Intracerebellar "fibroma" Case report JOSEFINA F. LLENA, M.D., HYUNG D. CHUNG, M.D., ASAO HIRANO, M.D., EMMANUEL H. FEIRING, M.D., AND HARRY M. ZIMMERMAN,M.D. Division of Neuropathology, Department of Pathology, and Department of Neurological Surgery, Montefiore Hospital and Medical Center, and Albert Einstein College of Medicine, Bronx, New York The authors report a unique case of intracerebellar fibroma; the tumor was well circumscribed and was treated by complete excision. KEY WORDS
"
cerebellum
9 benign tumor
9 fibroma
ENIGN tumors essentially composed of the skull revealed pronounced erosion of the fibroblastic elements are extremely sella turcica. A radioactive brain scan rare within the brain parenchyma. demonstrated an area of increased uptake in This is not surprising since paucity of con- the posterior fossa on the left side. A right nective tissue is a well-known feature of the brachial arteriogram showed evidence of brain. As far as we are aware, only 11 cases of hydrocephalus. In addition, the basilar artery benign fibrous tumors of the brain have been was pushed forward against the clivus, and reported. 1-4'6,s,9,12 All were located in the cere- abnormal vascularity was noted in the region brum. Recently, we came across a benign of the left cerebellar hemisphere. The fibrous tumor in the cerebellum. It was totally posterior inferior cerebellar artery appeared excised and showed certain interesting to be displaced medially and superiorly. Venhistological features which have not previ- triculography confirmed the diagnosis of a left cerebellar tumor. The lateral and third ously been described. ventricles and aqueduct were considerably dilated and the aqueduct and fourth ventricle C a s e Report were displaced anteriorly and to the right of This 19-year-old man was admitted on the midline. Operation. A suboccipital craniotomy was June 14, 1974, because of headaches dating back to the fall of the preceding year. For a performed on June 18, 1974, with the patient month prior to admission, he had had in the upright position. Immediately beneath difficulty in focusing his eyes and his gait had the surface of the left cerebellar hemisphere, become unsteady. More recently, he had an avascular, solid, firm, encapsulated, grayish-yellow tumor, about the size of a golf vomited and experienced double vision. Examination. He had papilledema and a ball, was present. Nowhere did it appear to be somewhat broad-based gait. X-ray films of attached to dura. It was totally removed after
B
98
J. Neurosurg. / Volume 43 /July, 1975
Intracerebellar "fibroma"
F~G. 1. Gross appearance of the cut surface of the tumor with ill-defined nodular pattern. Note the presence of thin capsule (arrows).
its blood supply was interrupted. The patient's postoperative course was entirely uneventful and he was discharged July 3, 1974. Pathological Examination. The specimen was a 5 X 4 X 4-cm firm, ovoid, pink-tan mass encapsulated by thin fibrous tissue. Cut F~. 2. Photomicrograph of tumor showing lobules of various sizes. H & E, X 10. surfaces (Fig. 1) were bulging and irregularly nodular, with whorled gray-white and smooth pale yellow areas. Multiple tissue blocks were embedded in paraffin, sectioned and stained with hematoxylin and eosin (H & E), Wilder reticulin, Masson trichrome, phosphotungstic acid hematoxylin (PTAH), elastic van Gieson, Bielschowsky, Alcian blue, periodic acid-Schiff, and mucicarmine stains. Frozen sections were stained with oil red " O " for fat. Microscopically, the lesion showed variously-sized lobules (Fig. 2) composed of spindle and stellate cells with myxoid and reticular matrices separated by irregular bands of collagenous tissue. It had moderate vascularity consisting mainly of capillaries and a few venous structures. A striking feature was a moderate amount of chronic inflammatory cell infiltrate, mostly plasma cells and lymphocytes, scattered throughout the lesion and remarkably dense at the periphery. In several areas, a "storiform" pattern of spindle cells associated with abundant intercellular reticulin was prominent (Fig. 3). Areas resembling granulation tissue were present in some lobules (Fig. 4). Mitotic figures were rare and not atypical. A few benign multinucleated cells were scattered throughout the lesion but no Touton-type FI~. 3. Photomicrograph of tumor showing giant cells were present. A few lipid- "storiform" pattern. Wilder reticulin stain, • 40. J. Neurosurg. / Volume 43 / July, 1975
99
j. F. l~lena, e t al.
FI~, 4. Photomicrograph of tumor showing areas resembling granulation tissue. H & E, • 40. containing macrophages were present around the capillaries. Whorl formation, psammoma bodies and nuclear palisades were not noted and no glial or other neural element was identified within or around the lesion. On the basis of its gross and histological features, the lesion was considered to be a benign mesenchymal tumor of fibroblastic origin.
Discussion To date, 11 cases of benign fibrous tumors have been reported? 4,6,s,~,12 Eight of these were described as fibroblastic in nature, intracerebral in location, and without dural attachment; most were firm and well circumscribed with the common histological feature of interlacing pattern of fibroblasts? -4,s'9,12 Three other cases diagnosed as fibrous xanthomas, with two characteristic histological features, namely, the "storiform" pattern of the spindle cells and the presence of a variable number of Touton-type giant cells, were recently reported by Kepes, et al. 6 100
In the present case, the gross appearance of the lesion was essentially similar to most of the I 1 reported cases. However, in addition to the basic histological pattern of interlacing bundles of spindle cells, there was a prominent chronic inflammatory cell infiltrate along with areas resembling granulation tissue. It should be noted that although a " s t o r i f o r m " pattern was present in many areas, Touton-type giant cells, which are characteristic of fibrous xanthomas, were absent. It seems to us, therefore, that the lesion in the present case is not exactly similar to any of the 11 cases mentioned above. In our opinion, the histological features in the present case have some resemblance to those of a lesion known to occur in the extracranial soft tissues, namely, nodular fasciitis) '7'x~ The latter is characterized by lobules of fibroblasts with numerous blood vessels, chronic inflammatory cell infiltrate, many areas resembling granulation tissue, and a variable number of multinucleated giant cells? ~ It is generally believed to be reactive in nature? ~ On the other hand, most of the histological features of our case, especially the " s t o r i f o r m " pattern, can also be observed in a n o t h e r soft tissue lesion described as fibrous h i s t i o c y t o m a and believed to be a true neoplasm. 11 Therefore, it is difficult to classify this lesion precisely, but we believe it was a benign mesenchymal tumor of fibroblastic origin with an unusually prominent chronic inflammatory cell infiltration. In the absence of a better terminology, this tumor is deemed to be a "fibroma" although we are aware of the general reluctance by pathologists to use this term for tumors other than the "congenital malformation composed of the normal fibrous elements of the corium covered by epidermis. ''xl To our knowledge, this is the first such lesion reported occurring in the cerebellum.
References 1. Alpers BJ, Yaskin JC, Grant FC: Primary fibroblastoma of the brain. Arch Neurol Psychlatry 27:270-281, 1932 2. Amezfia L: Fibroma intracerebral gigante recidivado. Hibernaci6n artificial. Aeta Neuropsiquiat Argent 4:15-22, 1958 3. Baker AB, Adams JM: Primary fibroblastoma of the brain. Report of a case. Am J Pathoi 13:129-137, 1937 J. Neurosurg. / Volume 43 / J u l y , 1975
Intracerebellar "fibroma" 4. Brucher JM, Hizawa K, Wechsler W: Ultrastructure d'un fibrome intrac6r6bral et possibilit~ de transformation maligne de ce type tumoral. Rev Neurol (Paris) 123:443-445, 1970 5. Hutter RVP, Stewart FW, Foote FW Jr: Fasciitis. A report of 70 cases with follow-up proving the benignity of the lesion. Cancer 15:992-1003, 1962 6. Kepes J J, Kepes M, Slowik F: Fibrous xanthomas and xanthosarcomas of the meninges and the brain. Acta Neuropathol (Bed) 23:187-199, 1973 7. Konwaler BE, Keasbey L, Kaplan L: Subcutaneous pseudosarcomatous fibromatosis (fasciitis). Am J Clin Pathol 25:241-252, 1955 8. Koos WT, Jellinger K, Sunder-Plassmann M: Intracerehral fibroma in an 1 l-month old infant. Case report. J Neurosurg 35:77-81, 1971 9. Meyer HH, Scheller H: ISIber ein Fibromyx-
J. Neurosurg. / Volume 43 / July, 1975
om des Gehirns. Virchow Arch (Pathol Anat) 300:473-486, 1937 10. Price EB, Jr., Silliphant WM, Shuman R: Nodular fasciitis: a clinicopathologic analysis of 65 cases. Am J Clin Pathol 35:122-136, 1961 11. Stout AP, Lattes R: Tumors of the soft tissues, in Atlas of Tumor Pathology, second series, fasc 1. Washington, D.C., Armed Forces Institute of Pathology, 1967 12. Zfilch KJ: Fibrome, in Olivecrona H, TSnnis
W (eds): Handbuch der Neurochirurgie,
Volume 3. Berlin, Springer-Verlag, 1956, p 467
Address reprint requests to." Josefina F. Llena, M.D., Division of Neuropathology, Montefiore Hospital and Medical Center, 111 East 210 Street, Bronx, New York 10467.
10]
"
cerebellum
9 benign tumor
9 fibroma
ENIGN tumors essentially composed of the skull revealed pronounced erosion of the fibroblastic elements are extremely sella turcica. A radioactive brain scan rare within the brain parenchyma. demonstrated an area of increased uptake in This is not surprising since paucity of con- the posterior fossa on the left side. A right nective tissue is a well-known feature of the brachial arteriogram showed evidence of brain. As far as we are aware, only 11 cases of hydrocephalus. In addition, the basilar artery benign fibrous tumors of the brain have been was pushed forward against the clivus, and reported. 1-4'6,s,9,12 All were located in the cere- abnormal vascularity was noted in the region brum. Recently, we came across a benign of the left cerebellar hemisphere. The fibrous tumor in the cerebellum. It was totally posterior inferior cerebellar artery appeared excised and showed certain interesting to be displaced medially and superiorly. Venhistological features which have not previ- triculography confirmed the diagnosis of a left cerebellar tumor. The lateral and third ously been described. ventricles and aqueduct were considerably dilated and the aqueduct and fourth ventricle C a s e Report were displaced anteriorly and to the right of This 19-year-old man was admitted on the midline. Operation. A suboccipital craniotomy was June 14, 1974, because of headaches dating back to the fall of the preceding year. For a performed on June 18, 1974, with the patient month prior to admission, he had had in the upright position. Immediately beneath difficulty in focusing his eyes and his gait had the surface of the left cerebellar hemisphere, become unsteady. More recently, he had an avascular, solid, firm, encapsulated, grayish-yellow tumor, about the size of a golf vomited and experienced double vision. Examination. He had papilledema and a ball, was present. Nowhere did it appear to be somewhat broad-based gait. X-ray films of attached to dura. It was totally removed after
B
98
J. Neurosurg. / Volume 43 /July, 1975
Intracerebellar "fibroma"
F~G. 1. Gross appearance of the cut surface of the tumor with ill-defined nodular pattern. Note the presence of thin capsule (arrows).
its blood supply was interrupted. The patient's postoperative course was entirely uneventful and he was discharged July 3, 1974. Pathological Examination. The specimen was a 5 X 4 X 4-cm firm, ovoid, pink-tan mass encapsulated by thin fibrous tissue. Cut F~. 2. Photomicrograph of tumor showing lobules of various sizes. H & E, X 10. surfaces (Fig. 1) were bulging and irregularly nodular, with whorled gray-white and smooth pale yellow areas. Multiple tissue blocks were embedded in paraffin, sectioned and stained with hematoxylin and eosin (H & E), Wilder reticulin, Masson trichrome, phosphotungstic acid hematoxylin (PTAH), elastic van Gieson, Bielschowsky, Alcian blue, periodic acid-Schiff, and mucicarmine stains. Frozen sections were stained with oil red " O " for fat. Microscopically, the lesion showed variously-sized lobules (Fig. 2) composed of spindle and stellate cells with myxoid and reticular matrices separated by irregular bands of collagenous tissue. It had moderate vascularity consisting mainly of capillaries and a few venous structures. A striking feature was a moderate amount of chronic inflammatory cell infiltrate, mostly plasma cells and lymphocytes, scattered throughout the lesion and remarkably dense at the periphery. In several areas, a "storiform" pattern of spindle cells associated with abundant intercellular reticulin was prominent (Fig. 3). Areas resembling granulation tissue were present in some lobules (Fig. 4). Mitotic figures were rare and not atypical. A few benign multinucleated cells were scattered throughout the lesion but no Touton-type FI~. 3. Photomicrograph of tumor showing giant cells were present. A few lipid- "storiform" pattern. Wilder reticulin stain, • 40. J. Neurosurg. / Volume 43 / July, 1975
99
j. F. l~lena, e t al.
FI~, 4. Photomicrograph of tumor showing areas resembling granulation tissue. H & E, • 40. containing macrophages were present around the capillaries. Whorl formation, psammoma bodies and nuclear palisades were not noted and no glial or other neural element was identified within or around the lesion. On the basis of its gross and histological features, the lesion was considered to be a benign mesenchymal tumor of fibroblastic origin.
Discussion To date, 11 cases of benign fibrous tumors have been reported? 4,6,s,~,12 Eight of these were described as fibroblastic in nature, intracerebral in location, and without dural attachment; most were firm and well circumscribed with the common histological feature of interlacing pattern of fibroblasts? -4,s'9,12 Three other cases diagnosed as fibrous xanthomas, with two characteristic histological features, namely, the "storiform" pattern of the spindle cells and the presence of a variable number of Touton-type giant cells, were recently reported by Kepes, et al. 6 100
In the present case, the gross appearance of the lesion was essentially similar to most of the I 1 reported cases. However, in addition to the basic histological pattern of interlacing bundles of spindle cells, there was a prominent chronic inflammatory cell infiltrate along with areas resembling granulation tissue. It should be noted that although a " s t o r i f o r m " pattern was present in many areas, Touton-type giant cells, which are characteristic of fibrous xanthomas, were absent. It seems to us, therefore, that the lesion in the present case is not exactly similar to any of the 11 cases mentioned above. In our opinion, the histological features in the present case have some resemblance to those of a lesion known to occur in the extracranial soft tissues, namely, nodular fasciitis) '7'x~ The latter is characterized by lobules of fibroblasts with numerous blood vessels, chronic inflammatory cell infiltrate, many areas resembling granulation tissue, and a variable number of multinucleated giant cells? ~ It is generally believed to be reactive in nature? ~ On the other hand, most of the histological features of our case, especially the " s t o r i f o r m " pattern, can also be observed in a n o t h e r soft tissue lesion described as fibrous h i s t i o c y t o m a and believed to be a true neoplasm. 11 Therefore, it is difficult to classify this lesion precisely, but we believe it was a benign mesenchymal tumor of fibroblastic origin with an unusually prominent chronic inflammatory cell infiltration. In the absence of a better terminology, this tumor is deemed to be a "fibroma" although we are aware of the general reluctance by pathologists to use this term for tumors other than the "congenital malformation composed of the normal fibrous elements of the corium covered by epidermis. ''xl To our knowledge, this is the first such lesion reported occurring in the cerebellum.
References 1. Alpers BJ, Yaskin JC, Grant FC: Primary fibroblastoma of the brain. Arch Neurol Psychlatry 27:270-281, 1932 2. Amezfia L: Fibroma intracerebral gigante recidivado. Hibernaci6n artificial. Aeta Neuropsiquiat Argent 4:15-22, 1958 3. Baker AB, Adams JM: Primary fibroblastoma of the brain. Report of a case. Am J Pathoi 13:129-137, 1937 J. Neurosurg. / Volume 43 / J u l y , 1975
Intracerebellar "fibroma" 4. Brucher JM, Hizawa K, Wechsler W: Ultrastructure d'un fibrome intrac6r6bral et possibilit~ de transformation maligne de ce type tumoral. Rev Neurol (Paris) 123:443-445, 1970 5. Hutter RVP, Stewart FW, Foote FW Jr: Fasciitis. A report of 70 cases with follow-up proving the benignity of the lesion. Cancer 15:992-1003, 1962 6. Kepes J J, Kepes M, Slowik F: Fibrous xanthomas and xanthosarcomas of the meninges and the brain. Acta Neuropathol (Bed) 23:187-199, 1973 7. Konwaler BE, Keasbey L, Kaplan L: Subcutaneous pseudosarcomatous fibromatosis (fasciitis). Am J Clin Pathol 25:241-252, 1955 8. Koos WT, Jellinger K, Sunder-Plassmann M: Intracerehral fibroma in an 1 l-month old infant. Case report. J Neurosurg 35:77-81, 1971 9. Meyer HH, Scheller H: ISIber ein Fibromyx-
J. Neurosurg. / Volume 43 / July, 1975
om des Gehirns. Virchow Arch (Pathol Anat) 300:473-486, 1937 10. Price EB, Jr., Silliphant WM, Shuman R: Nodular fasciitis: a clinicopathologic analysis of 65 cases. Am J Clin Pathol 35:122-136, 1961 11. Stout AP, Lattes R: Tumors of the soft tissues, in Atlas of Tumor Pathology, second series, fasc 1. Washington, D.C., Armed Forces Institute of Pathology, 1967 12. Zfilch KJ: Fibrome, in Olivecrona H, TSnnis
W (eds): Handbuch der Neurochirurgie,
Volume 3. Berlin, Springer-Verlag, 1956, p 467
Address reprint requests to." Josefina F. Llena, M.D., Division of Neuropathology, Montefiore Hospital and Medical Center, 111 East 210 Street, Bronx, New York 10467.
10]
