Adenomatosis of minor salivary glands Report
of a case
Shelley AI. Khullar, ABERDEEN
UNIVERSITY
FDSRCS,” and Philip V. Best, FRCPath,b Aberdeen, Scotland AND
ABERDEEN
ROYAL
INFIRMARY
An account is given of a patient who had multiple canalicular adenomas in the upper lip and adjacent oral mucosa. A few months after these had been excised, several more tumors of the same type developed. Microscopic examination also revealed numerous tiny foci of adenomatous proliferation within otherwise normal salivary gland lobules. We suggest that this phenomenon represents a field neoplastic change although it appears to be benign. (ORAL SURC ORAL MED
ORAL PATHOL
1992;74:783-7)
A lthough controversy still exists about the nomenclature of some of the monomorphic salivary gland adenomas, a distinction between canalicular adenoma and so-called basal cell adenoma now seems, acceptable.‘, 2 By far the most common site of origin of the canalicular adenoma is the minor salivary glands in or near the upper lip,3-5 and the tumor is usually solitary without recurrence after surgical excision. Separate microscopic islands of similar neoplasia in salivary gland lobules in the immediate vicinity of the main mass have been described,4-7 but these have not usually been associated with clinical recurrence in the follow-up period. There have been a few reports of patients with more than one adenoma in or close to the upper lip, which appear either synchronously or metachronously. 5, 7-13 We report on a patient who had multiple adenomas when first seen and who developed several more in the following few months. Case Report The patient, a 59-year-old man, presented in March 1991, with “cysts” in his mouth that had appeared and slowly increased in size over a period of about 4 years. These were causing him trouble when he ate but were not associated with any pain or loss of function. Examination revealed six lesions in the upper right quadrant of the buccal mucosa and one, which was the largest-l.5 cm in diameter, in the upper labial midline. The lesions were excised with the patient under general anesthesia in April 1991, and healing was uneventful. aRegistrar, Department of Oral and Maxillofacial Surgery, Aberdeen Royal Infirmary. bConsultant/Senior Lecturer, Department of Pathology, University of Aberdeen. 7/14/41490
When the patient came for review in May 1991, he was found to have developed multiple new palpable mucosal lesions, but this time they were mainly confined to the upper lip and anterior buccal mucosa (from about the level of the right upper first molar tooth to that of the left canine). None seemed larger than about 0.5 cm in diameter. A total of 7 macroscopically identifiable lesions were excised in June 1991. When the patient was examined again in October 1991, six or seven new nodules were identified, situated bilaterally in the buccal mucosa and upper lip, but at this stage he declined to have further surgical treatment. Pathologic
results
The specimen from the first surgical procedure comprised six pieces of soft, pinkish-grey tissue, and ranged in maximum diameter from 0.7 to 2.3 cm. The outer surfaces were partly smooth, partly irregular, and friable. Microscopically the appearances of each fragment were strikingly similar (Figs. 1 and 2), and consisted of a tubular and trabecular structure formed by single or double layers of columnar or cuboidal epithelial cells. Some of the bilayered trabeculae showed foci of separation of the two layers around small luminal spaces, giving a beaded appearance. The nuclei were uniform, ovoid, and placed either centrally or slightly nearer the base than the luminal surface of tubules; occasional mitotic figures were identified. Myoepithelial cells were absent. A single dilated tubule was found in which the epithelium was partly of the usual columnar form, but the remainder was of oxyphil type. The palestained, sparsely cellular stroma contained thin-walled blood vessels surrounded by an alcianophilic matrix, in which there were occasional fibroblasts and collagen fibres. A few groups of siderophages were present. In the stroma there were no chondroid features, stellate epithelial cells, or myoepithelial cells. Most of the nodules did not have a recognizable capsule. 783
784
KhuElar and Best
ORAL
SUROOKAL
M~ORA~PATU~L
December 1992
Fig. 1. Specimen from first surgical procedure shows predominantly tubular structure. Note sparsely cellular stroma that contains capillary vessels. (Hematoxylin-eosin stain; original magnification X185.)
Electron
Microscopic
results
(Fig. 3)
Tumor nuclei were regular, contained euchromatin, and had a single prominent nucleolus. The base of the cells rested on a single, thin, continuous basement membrane, and at the luminal surface there were scanty, poorly-formed microvilli. Junction complexes could be seen near the luminal surface of adjacent cells, and there were occasional desmosomes elsewhere, although these were not associated with tonofilament bundles. The cytoplasm contained moderate numbers of profiles of rough endoplasmic reticulum, plentiful polyribosomes, and microvesicles. Mitochondria were relatively scanty. Secondary lysosomes, usually near the cell base, were common. Occasional dense granules, probably secretory, were identified. The specimen from the second surgical procedure was in seven parts, six of them were single fragments of tissue that ranged from 0.5 to 1.6 cm in maximum dimension, and one that consisted of three separate portions of tissue, 0.5 to 2 cm in maximum dimension. Microscopically all but one of the fragments contained multiple discrete adenomatous nodules; the seventh was a solitary adenoma. The largest nodule was 7 mm in diameter, and the smallest lesions were
ig. 2. Specimen from first surgical procedure shows bilayered trabecular pattern. (Hematoxylin-eosin stain; origX 185.) inal magnification
ill-defined foci of canalicular adenomatous proliferation within intact salivary gland lobules (Fig. 4). The structure of the individual tumors was essentially the same as that in the first specimen, although some had a more clearly defined fibrous capsule, and a few were cystic.
Although the occurrence of multicentric canalicular adenomas in minor salivary glands, usually in or near the upper lip, is a recognized phenomenon, it has mostly been identified as tiny satellite lesions in close proximity to a single presenting tumor of the same type.4-6 The additional neoplastic foci were essentially an incidental microscopic finding and were not associated with clinical recurrence in the reported follow-up period. The development of more than one clinically manifest adenoma in an individual patient is rare and even in some of these, further overt tumors have not arisen after the initial surgical treatment. The first reported example of clinically manifest multifocal neoplasia in minor salivary glands of the
Volume 74 Number 6
Adenomatosis
of minor
salivary
glands
785
Fig. 3. Electron micrograph of tubular component of adenoma shows columnar cells with uniform nuclei, thin single-layered basal lamina (curved arrow), poorly formed or absent microvilli (open arrowhead), cisternae of rough endoplasmic reticulum (R), sparsemitochondria (closed arrowhead), and scanty desmosomes (long arrow] lacking associatedtonofilaments. Note absenceof basal plasmalemmal invaginations and secretory vacuoles. (Original magnification X9700.)
UPPer Pipseems to be. that of de la Pava et al. in 1966’; alth ough the tumors were diagnosed as glandular can :inoma, they would probably now be regarded by mosit pathologists as, canalicular adenomas. The pa-
tient described by Sarangapani and McCarth y9 h;ad small adenomas (up to 5 mm in maximum dim< n) around a larger cystic one in the upper lip. In the e:xampl.es of monomorphic adenomas reported by Min tz
786
Khullar and Best
4. Specimen from second surgical procedure shows focal, partly cystic, microadenomatous proliferation at different stagesof development within gland lobules. (Hematoxylin-eosin stain; original magnification X70.)
Fig.
et al.,“’ one patient had two tumors in the upper lip. Only one of the 11 patients with multiple incipient neoplastic foci around the main tumor described by Daley5 subsequently developed a second adenoma; it was in the same part of the upper lip and was removed 12 years after the first. In the large series of minor salivary gland tumors reviewed by Regezi et a1.,12 neoplasia recurred in only 2 of 23 cases of canalicular adenoma, and one of these was multifocal. In the group of patients studied by Neville et a1.,13two each had two simultaneous, bilateral adenomas of the upper lip, and another person developed a second adenoma 5 years after the first. The patient described by Mair and Stalsberg7 had five manifest adenomas at presentation and multiple microadenomas in adjacent salivary tissue, but there was no clinical evidence of recurrence up to 1 year after surgery. The second of the two patients reported by Ahren and Lindstromlo developed numerous miliary nonprogressive nodules in the lower lip after removal of multiple adenomas of
the upper lip, but the lower lip lesions were not sampled for histologic diagnosis and therefore cannot be unequivocally accepted as additional adenomas. Our patient is very unusual in that he had multiple obvious canalicular adenomas at first presentation, and he developed several more in the following few months. Multiple microscopic foci of neoplastic change were found in minor salivary gland lobules in addition to the macroscopically identifiable tumor nodules. Only two cases described in the literature appear to be comparable.8, l2 Study of the light microscopic appearances and ultrastructure of the multifocal neoplasia in our patient leads us to concur with the view previously expressed that the site of origin is likely to be the intercalated duct.‘O>r4, t5 The microscopic adenomatous foci within otherwise intact salivary lobules seem to indicate the location of initial neoplastic transformation. A derivation from acinar cells themselves is highly unlikely in view of the ductlike architecture of the tumor and the minimal evidence of secretory activity. Eversole” 5 pointed out that only striated and intercalated ducts are present within lobules. Striated duct epithelium has deep basal plasmalemmal imaginations, secretory vacuoles, and abundant mitochondria, none of which are features of the tumor cells in our patient. The absence, however, of myoepithelium is perhaps a point against intercalated duct derivation. De la Pava et a1.8 thought that the multicentric tumors resulted from a carcinogenic stimulus acting on widely separated accessory salivary glands, but Daley5 argued against the field cancerization interpretation lest this should lead to unnecessary surgery. We feel that the appearances do point to a field change, even though the neoplasia remains benign. The patient described by de la Pava et a1.8 was a long-standing pipe smoker, but smoking has not been mentioned as a possible etiologic factor in other cases, and our patient is a nonsmoker. The predilection for involvement of the glands in the upper lip has also to be explained. With regard to management of patients with multifocal canalicular adenoma, it seems that local excision of symptomatic nodules is sufficient. Despite the presence of multicentric microscopic abnormality in the minor salivary glandular tissue, recurrent macroscopic growths are remarkably rare. Mair and Stalsberg7 suggested that this could be due to slow growth with long latent periods or that the epithelial change may represent a multifocal developmental dysplasia, which does not necessarily become neoplastic. Our patient, however, illustrates that recurrences can occasionally arise after a short time, which indicates a high neoplastic potential. Although malignant transformation has not so far been reported in such tumors,
Volume Number
Adenomatosis
74 6
it would probably be prudent to keep affected persons under observation.
8.
We are grateful to Mr. R. Bainton for permission to publish
clinical
details
of .the patient
who
was
under
his care,
to the staff of the Electron Microscopy Unit, Department of Pathology, Aberdeen, for invaluable technical assistance, and to Mrs. I.M. Watson for typing the manuscript.
9. 10.
11.
REFERENCES 1. Daley TD, Gardner DG, Smout MS. Canalicular not a basal cell adenoma. ORAL SURG ORAL PATHOL
adenoma: MED
ORAL
1984;57:181-8.
2. Chen SY, Miller AS. Canalicular adenoma of the upper lip: an electron microscopic study. Cancer 1980;46:552-6. 3. Nelson JF, Jacoway JR. Monomorphic adenoma (canalicular type): report of 29 cases. Cancer 1973;31:1511-3. 4. Fantasia JE, Neville BW. Basal cell adenomas of the minor salivary glands: a clinicopathologic study of seventeen new cases and a review of the literature. ORAL SURG ORAL MED ORAL
PATHOL
1980;50:433-40.
5. Daley TD. The canalicular adenoma: considerations on differential diagnosis and treatment. J Oral Maxillofac Surg 1984; 42:728-30. 6. Klein HZ, Goldman RL. Basal cell adenoma of the upper lip. Arch Path01 1973;95:94-6. 7. Mair IWS, Stalsberg H. Basal cell adenomatosis of minor sal-
of minor salivary glands
787
ivary glands of the upper lip. Arch Otorhinolaryngol 1988; 245:191-5. de la Pava S, Karjoo R, Mukhtar E, Pickren JW. Multifocal carcinoma of accessory salivary gland: a case report. Cancer 1966;19:1308-10. Sarangapani K, McCarthy J. Multiple cystic adenomas of labial salivary glands. Br J Oral Surg 1977-78; 15: 166-70. Ahren C, Lindstrom J. Adenomatosis of accessory salivary glands of the lip: report of two cases. ORL J Otorhinolaryngol Relat Spec 1977;39:161-6. Mintz GA, Abrams AM, Melrose RJ. Monomorphic adenomas of the major and minor salivary glands. ORAL SURG ORAL
MED
ORAL
PATHOL
1982;53:375-86.
12. Regezi JA, Lloyd RV, Zarbo RJ, McClatchey KD. Minor salivary gland tumors: a histologic and immunohistochemical study. Cancer 1985;55:108-15. 13. Neville BW, Damm DD, Weir JC, Fantasia JE. Labial salivary gland tumors. Cancer 1988;61:2113-6. 14. Christ TF, Cracker D. Basal cell adenoma of minor salivary gland origin. Cancer 1972;30:214-9. 15. Eversole LR. Histogenic classification of salivary tumors. Arch Path01 1971;92:433-43. Reprint requests: Philip V. Best, FRCPath Department of Pathology Medical School Foresterhill, Aberdeen AB9 2ZD, Scotland
BOUND VOLUMES AVAILABLE TO SUBSCRIBERS Bound volumes of ORAL SURGERY, ORAL MEDICINE, AND ORAL PATHOLOGY are available to subscribers (only) for the 1991 issues from the Publisher, at a cost of $45.00 for domestic, $60.15 for Canadian, and $57.00 for international, for Vol. 71 (January-June) and Vol. 72 (July-December). Shipping charges are included. Each bound volume contains a subject and author index and all advertising is removed. Copies are shipped within 60 days after publication of the last issue in the volume. The binding is durable buckram with the journal name, volume number, and year stamped in gold on the spine. Payment must accompan,y all orders. Contact Mosby-Year Book, Inc., Subscription Services, 11830 Westline Industrial Drive, St. Louis, MO 63146-3318, USA; phone (800)325-4177, ext. 4351, or (314)453-4351. Subscriptions must be in force to qualify. Bound volumes are not available in place of a regular journal subscription.
of a case
Shelley AI. Khullar, ABERDEEN
UNIVERSITY
FDSRCS,” and Philip V. Best, FRCPath,b Aberdeen, Scotland AND
ABERDEEN
ROYAL
INFIRMARY
An account is given of a patient who had multiple canalicular adenomas in the upper lip and adjacent oral mucosa. A few months after these had been excised, several more tumors of the same type developed. Microscopic examination also revealed numerous tiny foci of adenomatous proliferation within otherwise normal salivary gland lobules. We suggest that this phenomenon represents a field neoplastic change although it appears to be benign. (ORAL SURC ORAL MED
ORAL PATHOL
1992;74:783-7)
A lthough controversy still exists about the nomenclature of some of the monomorphic salivary gland adenomas, a distinction between canalicular adenoma and so-called basal cell adenoma now seems, acceptable.‘, 2 By far the most common site of origin of the canalicular adenoma is the minor salivary glands in or near the upper lip,3-5 and the tumor is usually solitary without recurrence after surgical excision. Separate microscopic islands of similar neoplasia in salivary gland lobules in the immediate vicinity of the main mass have been described,4-7 but these have not usually been associated with clinical recurrence in the follow-up period. There have been a few reports of patients with more than one adenoma in or close to the upper lip, which appear either synchronously or metachronously. 5, 7-13 We report on a patient who had multiple adenomas when first seen and who developed several more in the following few months. Case Report The patient, a 59-year-old man, presented in March 1991, with “cysts” in his mouth that had appeared and slowly increased in size over a period of about 4 years. These were causing him trouble when he ate but were not associated with any pain or loss of function. Examination revealed six lesions in the upper right quadrant of the buccal mucosa and one, which was the largest-l.5 cm in diameter, in the upper labial midline. The lesions were excised with the patient under general anesthesia in April 1991, and healing was uneventful. aRegistrar, Department of Oral and Maxillofacial Surgery, Aberdeen Royal Infirmary. bConsultant/Senior Lecturer, Department of Pathology, University of Aberdeen. 7/14/41490
When the patient came for review in May 1991, he was found to have developed multiple new palpable mucosal lesions, but this time they were mainly confined to the upper lip and anterior buccal mucosa (from about the level of the right upper first molar tooth to that of the left canine). None seemed larger than about 0.5 cm in diameter. A total of 7 macroscopically identifiable lesions were excised in June 1991. When the patient was examined again in October 1991, six or seven new nodules were identified, situated bilaterally in the buccal mucosa and upper lip, but at this stage he declined to have further surgical treatment. Pathologic
results
The specimen from the first surgical procedure comprised six pieces of soft, pinkish-grey tissue, and ranged in maximum diameter from 0.7 to 2.3 cm. The outer surfaces were partly smooth, partly irregular, and friable. Microscopically the appearances of each fragment were strikingly similar (Figs. 1 and 2), and consisted of a tubular and trabecular structure formed by single or double layers of columnar or cuboidal epithelial cells. Some of the bilayered trabeculae showed foci of separation of the two layers around small luminal spaces, giving a beaded appearance. The nuclei were uniform, ovoid, and placed either centrally or slightly nearer the base than the luminal surface of tubules; occasional mitotic figures were identified. Myoepithelial cells were absent. A single dilated tubule was found in which the epithelium was partly of the usual columnar form, but the remainder was of oxyphil type. The palestained, sparsely cellular stroma contained thin-walled blood vessels surrounded by an alcianophilic matrix, in which there were occasional fibroblasts and collagen fibres. A few groups of siderophages were present. In the stroma there were no chondroid features, stellate epithelial cells, or myoepithelial cells. Most of the nodules did not have a recognizable capsule. 783
784
KhuElar and Best
ORAL
SUROOKAL
M~ORA~PATU~L
December 1992
Fig. 1. Specimen from first surgical procedure shows predominantly tubular structure. Note sparsely cellular stroma that contains capillary vessels. (Hematoxylin-eosin stain; original magnification X185.)
Electron
Microscopic
results
(Fig. 3)
Tumor nuclei were regular, contained euchromatin, and had a single prominent nucleolus. The base of the cells rested on a single, thin, continuous basement membrane, and at the luminal surface there were scanty, poorly-formed microvilli. Junction complexes could be seen near the luminal surface of adjacent cells, and there were occasional desmosomes elsewhere, although these were not associated with tonofilament bundles. The cytoplasm contained moderate numbers of profiles of rough endoplasmic reticulum, plentiful polyribosomes, and microvesicles. Mitochondria were relatively scanty. Secondary lysosomes, usually near the cell base, were common. Occasional dense granules, probably secretory, were identified. The specimen from the second surgical procedure was in seven parts, six of them were single fragments of tissue that ranged from 0.5 to 1.6 cm in maximum dimension, and one that consisted of three separate portions of tissue, 0.5 to 2 cm in maximum dimension. Microscopically all but one of the fragments contained multiple discrete adenomatous nodules; the seventh was a solitary adenoma. The largest nodule was 7 mm in diameter, and the smallest lesions were
ig. 2. Specimen from first surgical procedure shows bilayered trabecular pattern. (Hematoxylin-eosin stain; origX 185.) inal magnification
ill-defined foci of canalicular adenomatous proliferation within intact salivary gland lobules (Fig. 4). The structure of the individual tumors was essentially the same as that in the first specimen, although some had a more clearly defined fibrous capsule, and a few were cystic.
Although the occurrence of multicentric canalicular adenomas in minor salivary glands, usually in or near the upper lip, is a recognized phenomenon, it has mostly been identified as tiny satellite lesions in close proximity to a single presenting tumor of the same type.4-6 The additional neoplastic foci were essentially an incidental microscopic finding and were not associated with clinical recurrence in the reported follow-up period. The development of more than one clinically manifest adenoma in an individual patient is rare and even in some of these, further overt tumors have not arisen after the initial surgical treatment. The first reported example of clinically manifest multifocal neoplasia in minor salivary glands of the
Volume 74 Number 6
Adenomatosis
of minor
salivary
glands
785
Fig. 3. Electron micrograph of tubular component of adenoma shows columnar cells with uniform nuclei, thin single-layered basal lamina (curved arrow), poorly formed or absent microvilli (open arrowhead), cisternae of rough endoplasmic reticulum (R), sparsemitochondria (closed arrowhead), and scanty desmosomes (long arrow] lacking associatedtonofilaments. Note absenceof basal plasmalemmal invaginations and secretory vacuoles. (Original magnification X9700.)
UPPer Pipseems to be. that of de la Pava et al. in 1966’; alth ough the tumors were diagnosed as glandular can :inoma, they would probably now be regarded by mosit pathologists as, canalicular adenomas. The pa-
tient described by Sarangapani and McCarth y9 h;ad small adenomas (up to 5 mm in maximum dim< n) around a larger cystic one in the upper lip. In the e:xampl.es of monomorphic adenomas reported by Min tz
786
Khullar and Best
4. Specimen from second surgical procedure shows focal, partly cystic, microadenomatous proliferation at different stagesof development within gland lobules. (Hematoxylin-eosin stain; original magnification X70.)
Fig.
et al.,“’ one patient had two tumors in the upper lip. Only one of the 11 patients with multiple incipient neoplastic foci around the main tumor described by Daley5 subsequently developed a second adenoma; it was in the same part of the upper lip and was removed 12 years after the first. In the large series of minor salivary gland tumors reviewed by Regezi et a1.,12 neoplasia recurred in only 2 of 23 cases of canalicular adenoma, and one of these was multifocal. In the group of patients studied by Neville et a1.,13two each had two simultaneous, bilateral adenomas of the upper lip, and another person developed a second adenoma 5 years after the first. The patient described by Mair and Stalsberg7 had five manifest adenomas at presentation and multiple microadenomas in adjacent salivary tissue, but there was no clinical evidence of recurrence up to 1 year after surgery. The second of the two patients reported by Ahren and Lindstromlo developed numerous miliary nonprogressive nodules in the lower lip after removal of multiple adenomas of
the upper lip, but the lower lip lesions were not sampled for histologic diagnosis and therefore cannot be unequivocally accepted as additional adenomas. Our patient is very unusual in that he had multiple obvious canalicular adenomas at first presentation, and he developed several more in the following few months. Multiple microscopic foci of neoplastic change were found in minor salivary gland lobules in addition to the macroscopically identifiable tumor nodules. Only two cases described in the literature appear to be comparable.8, l2 Study of the light microscopic appearances and ultrastructure of the multifocal neoplasia in our patient leads us to concur with the view previously expressed that the site of origin is likely to be the intercalated duct.‘O>r4, t5 The microscopic adenomatous foci within otherwise intact salivary lobules seem to indicate the location of initial neoplastic transformation. A derivation from acinar cells themselves is highly unlikely in view of the ductlike architecture of the tumor and the minimal evidence of secretory activity. Eversole” 5 pointed out that only striated and intercalated ducts are present within lobules. Striated duct epithelium has deep basal plasmalemmal imaginations, secretory vacuoles, and abundant mitochondria, none of which are features of the tumor cells in our patient. The absence, however, of myoepithelium is perhaps a point against intercalated duct derivation. De la Pava et a1.8 thought that the multicentric tumors resulted from a carcinogenic stimulus acting on widely separated accessory salivary glands, but Daley5 argued against the field cancerization interpretation lest this should lead to unnecessary surgery. We feel that the appearances do point to a field change, even though the neoplasia remains benign. The patient described by de la Pava et a1.8 was a long-standing pipe smoker, but smoking has not been mentioned as a possible etiologic factor in other cases, and our patient is a nonsmoker. The predilection for involvement of the glands in the upper lip has also to be explained. With regard to management of patients with multifocal canalicular adenoma, it seems that local excision of symptomatic nodules is sufficient. Despite the presence of multicentric microscopic abnormality in the minor salivary glandular tissue, recurrent macroscopic growths are remarkably rare. Mair and Stalsberg7 suggested that this could be due to slow growth with long latent periods or that the epithelial change may represent a multifocal developmental dysplasia, which does not necessarily become neoplastic. Our patient, however, illustrates that recurrences can occasionally arise after a short time, which indicates a high neoplastic potential. Although malignant transformation has not so far been reported in such tumors,
Volume Number
Adenomatosis
74 6
it would probably be prudent to keep affected persons under observation.
8.
We are grateful to Mr. R. Bainton for permission to publish
clinical
details
of .the patient
who
was
under
his care,
to the staff of the Electron Microscopy Unit, Department of Pathology, Aberdeen, for invaluable technical assistance, and to Mrs. I.M. Watson for typing the manuscript.
9. 10.
11.
REFERENCES 1. Daley TD, Gardner DG, Smout MS. Canalicular not a basal cell adenoma. ORAL SURG ORAL PATHOL
adenoma: MED
ORAL
1984;57:181-8.
2. Chen SY, Miller AS. Canalicular adenoma of the upper lip: an electron microscopic study. Cancer 1980;46:552-6. 3. Nelson JF, Jacoway JR. Monomorphic adenoma (canalicular type): report of 29 cases. Cancer 1973;31:1511-3. 4. Fantasia JE, Neville BW. Basal cell adenomas of the minor salivary glands: a clinicopathologic study of seventeen new cases and a review of the literature. ORAL SURG ORAL MED ORAL
PATHOL
1980;50:433-40.
5. Daley TD. The canalicular adenoma: considerations on differential diagnosis and treatment. J Oral Maxillofac Surg 1984; 42:728-30. 6. Klein HZ, Goldman RL. Basal cell adenoma of the upper lip. Arch Path01 1973;95:94-6. 7. Mair IWS, Stalsberg H. Basal cell adenomatosis of minor sal-
of minor salivary glands
787
ivary glands of the upper lip. Arch Otorhinolaryngol 1988; 245:191-5. de la Pava S, Karjoo R, Mukhtar E, Pickren JW. Multifocal carcinoma of accessory salivary gland: a case report. Cancer 1966;19:1308-10. Sarangapani K, McCarthy J. Multiple cystic adenomas of labial salivary glands. Br J Oral Surg 1977-78; 15: 166-70. Ahren C, Lindstrom J. Adenomatosis of accessory salivary glands of the lip: report of two cases. ORL J Otorhinolaryngol Relat Spec 1977;39:161-6. Mintz GA, Abrams AM, Melrose RJ. Monomorphic adenomas of the major and minor salivary glands. ORAL SURG ORAL
MED
ORAL
PATHOL
1982;53:375-86.
12. Regezi JA, Lloyd RV, Zarbo RJ, McClatchey KD. Minor salivary gland tumors: a histologic and immunohistochemical study. Cancer 1985;55:108-15. 13. Neville BW, Damm DD, Weir JC, Fantasia JE. Labial salivary gland tumors. Cancer 1988;61:2113-6. 14. Christ TF, Cracker D. Basal cell adenoma of minor salivary gland origin. Cancer 1972;30:214-9. 15. Eversole LR. Histogenic classification of salivary tumors. Arch Path01 1971;92:433-43. Reprint requests: Philip V. Best, FRCPath Department of Pathology Medical School Foresterhill, Aberdeen AB9 2ZD, Scotland
BOUND VOLUMES AVAILABLE TO SUBSCRIBERS Bound volumes of ORAL SURGERY, ORAL MEDICINE, AND ORAL PATHOLOGY are available to subscribers (only) for the 1991 issues from the Publisher, at a cost of $45.00 for domestic, $60.15 for Canadian, and $57.00 for international, for Vol. 71 (January-June) and Vol. 72 (July-December). Shipping charges are included. Each bound volume contains a subject and author index and all advertising is removed. Copies are shipped within 60 days after publication of the last issue in the volume. The binding is durable buckram with the journal name, volume number, and year stamped in gold on the spine. Payment must accompan,y all orders. Contact Mosby-Year Book, Inc., Subscription Services, 11830 Westline Industrial Drive, St. Louis, MO 63146-3318, USA; phone (800)325-4177, ext. 4351, or (314)453-4351. Subscriptions must be in force to qualify. Bound volumes are not available in place of a regular journal subscription.
