REPORT
RHABDOID TUMOR OF THE SKIN OMAR P. SANGUEZA, M.D., CHARLES K. MESHUL, PH.D., PASTOR SANGUEZA, M.D., ANI3 RAUL MENDOZA, M.D.
The following case report involves an individual with a tumor in the skin with secondary invasion into deeper structures. The neoplasm showed all the classic characteristics of a rhabdoid tumor, but had an unusual immunohistochemical staining pattern.
Abstract A tumor in the skin of a 42-year-old man was analyzed by light and electron microscopic study and immunohistochemistry. The tumor cells were large and contained eosinophilic, periodic acid-Schiff (PAs)-positive inclusions in the cytoplasm. Immunohistochemically, the neoplasm was positive for intermediate filaments, cytokeratin, vimentin, desmin, and alpha-1-antichimotrypsin, and negative for S-100 and leukocyte common antigen (LCA). Ultrastructurally, the cytoplasm and cellular processes of the cells were inundated with intermediate filaments, some of which were tightly bundled. Junctional complexes and secretory granules were absent. These features suggest a rhabdoid tumor: a malignant tumor of uncertain origin.
Case Report A 42-year-old man complained of a nodule in the lower third of his right leg. This nodule was first noticed 4 months earlier. A biopsy was performed at that time, but we were unable to obtain the results. A physical examination of the patient was unremarkable except for a firm nodule measuring 3 x 2 x 2 cm in the lower third of the right leg. The nodule appeared to be localized to the skin; however, when the biopsy was performed, it was evident that the tumor extended deeply into subcutaneous tissue and bone. The bulk of the tumor was removed and submitted to the pathology department.
Rhabdoid tumors are rare, highly aggressive tumors of undetermined origin. They were first reported in the kidney as variants of the Wilms tumor, and were named rhabdoid because of their resemblance to the rhabdomyosarcomas.' Since then there have been numerous reports of this tumor in other sites.-^"'^ Although this tumor usually affects young children, it may also be seen in adults. Characteristics of the rhabdoid tumor include cells with large eosinophilic cytoplasm containing PAS-positive inclusions and large nuclei with prominent nucleoli. The immunohistochemical staining pattern of this tumor is variable; the most constant feature is positive reactivity for keratin and vimentin. Under the electron microscope, rhabdoid tumors show characteristic cytoplasmic filaments that correspond to the eosinophilic inclusions seen with the light microscope.
Materials and Methods: The biopsy specimen consisted of multiple irregular, brown to red fragments of soft tissue and skin, admixed with fragments of bone. The entire specimen was fixed in formalin overnight and processed routinely. Multiple sections of the tumor were stained with hematoxylin and eosin, PAS, and Mallory trichrome. Additional sections were stained by an indirect two-step immuno-alkaline phosphatase technique using the following antibodies: cytokeratin (Hybritech, San Diego, CA), epithelial membrane antigen (EMA) (DAKO, Santa Barbara, CA), vimentin (DAKO), actin (ENZO. New York, NY), S-100 rabbit
(DAKO), S-100 mouse (Chemicon, Los Angeles, CA), alpha-1antichimotrypsin (DAKO), desmin (Biogenics, San Ramon, CA), and LCA (DAKO).
For electron microscopic study, a small piece of paraffinembedded tissue was cut and washed in xylene for 1.5 hours. It was then washed with a series of decreasing concentrations of ethanols, placed in aqueous 1% osmium tetroxide/1.5% potassium ferrocyanide for 1.5 hours, stained en bloc in aqueous 0.5% uranyl acetate, dehydrated, and embedded in Embed 812/Araldite (Electron Microscopy Sciences, Fort Washington, PA). Thick (0.5 |jm) sections were cut with an RMC 6000 ultramicrotome (RMC, Tucson, AZ) and stained with toluidine blue. The area of interest was localized with the light microscope, and thin sections (80 nm) were cut using a Diatome diamond knife. Sections were placed on 200 mesh nickel grids and stained with 4% methanolic uranyl acetate and 0.075% lead citrate. The sections were examined and photographed with a JEOL 1200 EX electron microscope (JEOL, Peabody, MA.)
From the Departments of Pathology and Medical Psychology, Oregon Health Sciences University School of Medicine, and the Laboratory Services, Veterans Affairs Medical Center, Portland, Oregon, and the Departments of Pathology and Surgery, Hospital Number 1, La Paz, Bolivia. Supported in part by a grant from the Department of Veterans Affairs to C.K. Meshul. Address for correspondence: Omar P. Sangueza, M.D., Department of Pathology (UHS 19), Oregon Health Sciences tJniversity, 3181 S.W. Sam Jackson Park Road, Portland, OR 97201. 484
Rliabdoid Tumor Sanguez.i et al.
Figure 2. High-power view of the tumor showing large cells with cytoplasmic inclusions (arrows), large vesiculated nuclei, and prominent nucleoli.
Figure t. Light microscopic study of the tumor showing involvement of the entire dermis. RESULTS On light microscopic study, the neoplasm involved the entire dermis (Fig. 1) and extended into the subcutaneous fat tissue, muscle, and bone. It consisted of large cells with eosinophilic cytoplasm, some of which contained PASpositive pink material. The nuclei were large and vacuolated and had prominent nucleoli (Fig. 2). All of these features are typical for a rhabdoid tumor. Immunoperoxidase stains showed a diffuse positive staining for cytokeratin, EMA, vimentin (Fig. 3), desmin,, and alpha-1-antichiniotrypsin, and were negative for LCA and S-100. Electron microscopic analysis showed nuclei con-, taining sparse heterochromatin, with some cells showing prominent nucleoli. There were moderate atnounts of rough endoplasmic reticulum within a limited perinuclear location (Fig. 4). Some free ribosomes were present, with poorly preserved mitochondria scattered throughout the cytoplasm. The most prominent cytoplasmic feature was the enormous accumulation of intermediate filaments, some of which were aggregated to form bundles of filaments (Fig. 5); these filaments were observed throughout the cytoplasm. There were no obvious desmosomal contacts between the cells, and the unusually large cellular processes were also filled with intermediate filaments. There was no evidence of secretory vesicle accumulation; however, prior formalin fixation could have disrupted the vesicles.
Figure 3. Immunohistochemistry of the tumor showing the perinuclear inclusions positive for vimentin (arrow). tumor has been shown to occur in other parts of the body.-''*'*"'•' There has only been one case of skin involvement reported."' Clinically, these tumors grow quickly and occur most commonly in young patients, although they may also be found in adults.'"•'''•''' The outcome is fatal in most cases. The histologic features of this tumor include large, round to polygonal cells with eosinophilic cytoplasmic inclusions and large vesiculated nuclei with prominent central nucleoli. The eosinophilic inclusions are perinuclear and positive for PAS. In some cases mitotic figures and multinucieated cells can be identified.Immunohistochemically, this tutnor characteristically reacts positively with cytokeratin and vimentin; however, some reports give conflicting results for other markers, leading to controversy over the histogenesis of the rhabdoid tumor. Epithelial,^-''"'"' myogenic,'-^'" histiocytic,'-' neural,'"'' and mesenchymal'^ origins have been
DISCUSSION
Rhabdoid tumors were first described in the kidney in 1970 as a variant of Wilms tumor.' Since then this 485
International Journal of Dermatology Vol. 31, No. 7, July 1992
and create the characteristic appearance of the tumor. Some of these features may also be present in other types of tumors. The extent or degree of intermediate filament accumulation is another unusual feature of the rhabdoid tumor. Based on our findings and literature review, we concur with Carter et al.'^ that the variable ultrastructural and immunohistochemical features of rhabdoid tumors may reflect diverse histogenesis.^' Another possibility is that the rhabdoid stage may result from morphologic transformation associated with its highly aggressive behavior. This is based on observations of the coexistence of a rhabdoid tumor with a transitional cell carcinoma of the bladder'" and the presence of rhabdoid cells in other soft tissue sarcomas.^^
Figure 4. Low power electron photomicrograph showing a typical tumor cell with a nucleus and small accumulation of rough endoplasmic reticulum around the nucleus, with the remainder of the cytoplasm filled with intermediate filaments. Calibration bar: 2.5 |jm.
A particular problem with this tumor is distinguishing it from epithelioid sarcomas. Both tumors are identical clinically, immunohistochemically, and electron microscopically; however, some investigators believe it is possible to differentiate these two neoplasms based on morphologic features. "*'^°'^-' They suggest that multiple nodules with central necrosis and cells with bland nuclear features simulating a granulomatous process are characteristic of epithelioid sarcoma. Rhabdoid tumors, however, are composed of large pleomorphic cells with prominent nucleoli and characteristic eosinophiiic perinuclear inclusions. We have seen cases of typical epithelioid sarcomas that have the same type of cell characteristically attributed to rhabdoid tumors. For this reason, we feel that it is sometimes difficult to differentiate between these tumors, except in the typical cases. Due to the fact that only two rhabdoid tumors of the skin have been reported to date (reference 16 and the current case), we cannot compare their behavior with that of epithelioid sarcomas; however, both are highly aggressive malignant t u m o r s and should be treated accordingly.
Figure 5. Higher power electron photomicrograph showing the bundling of intermediate filaments (arrow) within the cytoplasm. Also in view are short segments of rough endoplasmic reticulum. Calibration bar: 0.25 |im.
Acknowledgments: Marianne Brown assisted with the immunohistochemistry; Donna Normoyle assisted with the electron microscopic study; Medical Media Services, Veterans Affairs Medical Center, assisted with the light microscopic study; Lori Cohen typed and edited the manuscript; and Dr. Robert Erlandson, Memorial Sloan-Kettering Cancer Center, New York, reviewed the case. .
postulated, but no definitive proof has been establisbed for any of these. In the present case the neoplastic cells stained positively for vimentin, cytokeratin, EMA., actin, desmin, alpha-1-antitrypsin, and alpha-1-antichimotrypsin. Expression of cytokeratin and KMA are thought to denote epithelial differentiation.^" Vimentin, alpha-1antitrypsin, and alpha-1-antichimotrypsin stain tumors of mesenchymal differentiation, although vimentin can also be found in malignant epithelial tumors." Tumors associated with myogenic differentiation are positive for actin and desmin; therefore, the unusual results found in this case, where antibodies against desmin, cytokeratin, and vimentin tested positive, seem to support the possibility that this tumor originates from undifferentiated cells, tjltrastructural features of this tumor include collections of intermediate filaments near the nucleus, which correspond to the hyalin globules seen with the light microscope. These intermediate filaments form bundles
REFERENCES 1.
Haas JE, Palmer NF, Weinberg AG, et al. Ultrastructure of malignant rhahdoid tumor of the kidney. Hum Pathol 1981; 12:646-657.
2.
Kawanishi G, Tamura M, Akiyama K, et al. Rhabdoid tumors of the spermatic cord. Br J Urol 1989; 63: 439^40. Ekfors TO, Heikki JA, Kekomaki M. Malignant rhahdoid tumor of the prostatic region. Virchows Arch [A] 1985; 406:381-388. •
3.
486
Rhabdoid Tumor Sangueza et al.
4.
5. 6.
7.
8.
9.
Small EJ, Gordon GJ, Barrett B. Malignant rhabdoid tumor of the heart in an infant. Cancer 1985; 55: 2850-2853. Blatt J, Russo P, Taylor S. Extrarenal rhabdoid sarcoma. Med Pediatr Oncol 1986; 14:22t-226. Robson DB, Akbarnia BA, deMello D, et al. Malignant rhabdoid tumor of the thoracic spine. Spine t987; 12: 620-624. Bigss PJ, Garaen PD, Powers JM, et al. Malignant rhabdoid tumor of the central nervous system. Hum Pathol 1987; 18:332-337. Kent AL, Mahoney DH, Gresik MV, et al. Malignant rhabdoid tumor of the extremity. Cancer 1987; 60: 1056-1059. Dervan PA, Cahalane SF, Kneasfsey P, et al. Malignant rhabdoid tumor of soft tissue: an ultrastructural and immunohistological study of a pelvic tumor. Histopathology 1987; tl:183-t90.
15.
16.
17.
18.
19.
10.
Harris M, Eyden BP, Joglekar VM. Rhabdoid tumor of the bladder: a histological, ultrastructural and immunohistochemical study. Histopathology 1987; 11: 1083-1092. 11. Parham DM, Peiper SC, Robicheaus G, et al. Malignant rhabdoid tumor of the liver. Arch pathol Lab Med 1988; 112:61-64. 12. Jakate SM, Marsden HB, Ingram L. Primary rhabdoid tumor of the brain. Virchows Arch [A] 1988; 412: 393-397. 13. Carter RL, McCarthy KP, Al-Sam SZ, et al. Malignant rhabdoid tumor of the bladder with immunohistochemical and ultrastructural evidence suggesting histiocytic origin. Histophathology 1989; 14:179-190. 14. Tsokos MA, Kourakis G, Chandra RS, et al. Malignant
20.
21.
22.
23.
rhabdoid tumor of the kidney and soft tissues. Arch Pathol Lab Med 1989; 113:115-120. Lynch HT, Shurin SB, Dahms BB, et al. Paravertebral malignant rhabdoid tumor in infancy. Cancer 1983; 52: 290-296. Dabbs DJ, Park HK. Malignant rhabdoid skin tumor: an uncommon primary skin neoplasm. Ultrastructural and immunohistochemical analysis. J Cutan Pathol 1988; 15:109-115. Tsuneyoshi MA, Daimaru Y, Hashimoto H, et al. Malignant soft tissue neoplasm with the histologic features of renal rhabdoid tumors. Hum Pathol t985; 16:12351242. Molenaar WM, Dejon B, Dam-Meiring A, et al. Epithelioid sarcoma or malignant rhabdoid tumor of soft tissue? Epithelioid immunophenotype and rhabdoid karyotype. Hum Pathol 1989: 21:347-351. Zanetti G, Giangaspero F. Rhabdomyoblastic nature of cytoplasmic inclusions in malignant rhabdoid tumor. Hum Pathol 1982; 13:410. Perrone T, Swanson PE, Twiggs L, et al. Malignant rhabdoid tumor of the vulva: is distinction from epithelioid sarcoma possible? A pathologic and immunohistochemical study. Am J Surg Pathol 1989; 13:848-858. Weeks DA, Beckwith JB, Mierau GW. Rhabdoid tumor: an entity or a phenotype? Arch Pathol lab Med 1989; 113: 113-114. Tsuneyoshi M, Daimaru Y, Hashimoto H, et al. The existence of rhabdoid cells in specified soft tissue sarcomas: histopathological, ultrastructural and immunohistochemical evidence. Virchows Arch [A] 1987; 411: 509-514. Fisher C. Epithelioid sarcoma: the spectrum of ultrastructural differentiation in seven immunohistochemical defined cases. Hum Pathol 1988; 19:265-275.
"Contented." Virginia R. Edwards, Lighthouse Point, Florida. Oil Painting second place. American Academy of Dermatology Art Exhibit, Dallas, Texas 1991. Photograph courtesy of Dermik Laboratories, Inc. 487
RHABDOID TUMOR OF THE SKIN OMAR P. SANGUEZA, M.D., CHARLES K. MESHUL, PH.D., PASTOR SANGUEZA, M.D., ANI3 RAUL MENDOZA, M.D.
The following case report involves an individual with a tumor in the skin with secondary invasion into deeper structures. The neoplasm showed all the classic characteristics of a rhabdoid tumor, but had an unusual immunohistochemical staining pattern.
Abstract A tumor in the skin of a 42-year-old man was analyzed by light and electron microscopic study and immunohistochemistry. The tumor cells were large and contained eosinophilic, periodic acid-Schiff (PAs)-positive inclusions in the cytoplasm. Immunohistochemically, the neoplasm was positive for intermediate filaments, cytokeratin, vimentin, desmin, and alpha-1-antichimotrypsin, and negative for S-100 and leukocyte common antigen (LCA). Ultrastructurally, the cytoplasm and cellular processes of the cells were inundated with intermediate filaments, some of which were tightly bundled. Junctional complexes and secretory granules were absent. These features suggest a rhabdoid tumor: a malignant tumor of uncertain origin.
Case Report A 42-year-old man complained of a nodule in the lower third of his right leg. This nodule was first noticed 4 months earlier. A biopsy was performed at that time, but we were unable to obtain the results. A physical examination of the patient was unremarkable except for a firm nodule measuring 3 x 2 x 2 cm in the lower third of the right leg. The nodule appeared to be localized to the skin; however, when the biopsy was performed, it was evident that the tumor extended deeply into subcutaneous tissue and bone. The bulk of the tumor was removed and submitted to the pathology department.
Rhabdoid tumors are rare, highly aggressive tumors of undetermined origin. They were first reported in the kidney as variants of the Wilms tumor, and were named rhabdoid because of their resemblance to the rhabdomyosarcomas.' Since then there have been numerous reports of this tumor in other sites.-^"'^ Although this tumor usually affects young children, it may also be seen in adults. Characteristics of the rhabdoid tumor include cells with large eosinophilic cytoplasm containing PAS-positive inclusions and large nuclei with prominent nucleoli. The immunohistochemical staining pattern of this tumor is variable; the most constant feature is positive reactivity for keratin and vimentin. Under the electron microscope, rhabdoid tumors show characteristic cytoplasmic filaments that correspond to the eosinophilic inclusions seen with the light microscope.
Materials and Methods: The biopsy specimen consisted of multiple irregular, brown to red fragments of soft tissue and skin, admixed with fragments of bone. The entire specimen was fixed in formalin overnight and processed routinely. Multiple sections of the tumor were stained with hematoxylin and eosin, PAS, and Mallory trichrome. Additional sections were stained by an indirect two-step immuno-alkaline phosphatase technique using the following antibodies: cytokeratin (Hybritech, San Diego, CA), epithelial membrane antigen (EMA) (DAKO, Santa Barbara, CA), vimentin (DAKO), actin (ENZO. New York, NY), S-100 rabbit
(DAKO), S-100 mouse (Chemicon, Los Angeles, CA), alpha-1antichimotrypsin (DAKO), desmin (Biogenics, San Ramon, CA), and LCA (DAKO).
For electron microscopic study, a small piece of paraffinembedded tissue was cut and washed in xylene for 1.5 hours. It was then washed with a series of decreasing concentrations of ethanols, placed in aqueous 1% osmium tetroxide/1.5% potassium ferrocyanide for 1.5 hours, stained en bloc in aqueous 0.5% uranyl acetate, dehydrated, and embedded in Embed 812/Araldite (Electron Microscopy Sciences, Fort Washington, PA). Thick (0.5 |jm) sections were cut with an RMC 6000 ultramicrotome (RMC, Tucson, AZ) and stained with toluidine blue. The area of interest was localized with the light microscope, and thin sections (80 nm) were cut using a Diatome diamond knife. Sections were placed on 200 mesh nickel grids and stained with 4% methanolic uranyl acetate and 0.075% lead citrate. The sections were examined and photographed with a JEOL 1200 EX electron microscope (JEOL, Peabody, MA.)
From the Departments of Pathology and Medical Psychology, Oregon Health Sciences University School of Medicine, and the Laboratory Services, Veterans Affairs Medical Center, Portland, Oregon, and the Departments of Pathology and Surgery, Hospital Number 1, La Paz, Bolivia. Supported in part by a grant from the Department of Veterans Affairs to C.K. Meshul. Address for correspondence: Omar P. Sangueza, M.D., Department of Pathology (UHS 19), Oregon Health Sciences tJniversity, 3181 S.W. Sam Jackson Park Road, Portland, OR 97201. 484
Rliabdoid Tumor Sanguez.i et al.
Figure 2. High-power view of the tumor showing large cells with cytoplasmic inclusions (arrows), large vesiculated nuclei, and prominent nucleoli.
Figure t. Light microscopic study of the tumor showing involvement of the entire dermis. RESULTS On light microscopic study, the neoplasm involved the entire dermis (Fig. 1) and extended into the subcutaneous fat tissue, muscle, and bone. It consisted of large cells with eosinophilic cytoplasm, some of which contained PASpositive pink material. The nuclei were large and vacuolated and had prominent nucleoli (Fig. 2). All of these features are typical for a rhabdoid tumor. Immunoperoxidase stains showed a diffuse positive staining for cytokeratin, EMA, vimentin (Fig. 3), desmin,, and alpha-1-antichiniotrypsin, and were negative for LCA and S-100. Electron microscopic analysis showed nuclei con-, taining sparse heterochromatin, with some cells showing prominent nucleoli. There were moderate atnounts of rough endoplasmic reticulum within a limited perinuclear location (Fig. 4). Some free ribosomes were present, with poorly preserved mitochondria scattered throughout the cytoplasm. The most prominent cytoplasmic feature was the enormous accumulation of intermediate filaments, some of which were aggregated to form bundles of filaments (Fig. 5); these filaments were observed throughout the cytoplasm. There were no obvious desmosomal contacts between the cells, and the unusually large cellular processes were also filled with intermediate filaments. There was no evidence of secretory vesicle accumulation; however, prior formalin fixation could have disrupted the vesicles.
Figure 3. Immunohistochemistry of the tumor showing the perinuclear inclusions positive for vimentin (arrow). tumor has been shown to occur in other parts of the body.-''*'*"'•' There has only been one case of skin involvement reported."' Clinically, these tumors grow quickly and occur most commonly in young patients, although they may also be found in adults.'"•'''•''' The outcome is fatal in most cases. The histologic features of this tumor include large, round to polygonal cells with eosinophilic cytoplasmic inclusions and large vesiculated nuclei with prominent central nucleoli. The eosinophilic inclusions are perinuclear and positive for PAS. In some cases mitotic figures and multinucieated cells can be identified.Immunohistochemically, this tutnor characteristically reacts positively with cytokeratin and vimentin; however, some reports give conflicting results for other markers, leading to controversy over the histogenesis of the rhabdoid tumor. Epithelial,^-''"'"' myogenic,'-^'" histiocytic,'-' neural,'"'' and mesenchymal'^ origins have been
DISCUSSION
Rhabdoid tumors were first described in the kidney in 1970 as a variant of Wilms tumor.' Since then this 485
International Journal of Dermatology Vol. 31, No. 7, July 1992
and create the characteristic appearance of the tumor. Some of these features may also be present in other types of tumors. The extent or degree of intermediate filament accumulation is another unusual feature of the rhabdoid tumor. Based on our findings and literature review, we concur with Carter et al.'^ that the variable ultrastructural and immunohistochemical features of rhabdoid tumors may reflect diverse histogenesis.^' Another possibility is that the rhabdoid stage may result from morphologic transformation associated with its highly aggressive behavior. This is based on observations of the coexistence of a rhabdoid tumor with a transitional cell carcinoma of the bladder'" and the presence of rhabdoid cells in other soft tissue sarcomas.^^
Figure 4. Low power electron photomicrograph showing a typical tumor cell with a nucleus and small accumulation of rough endoplasmic reticulum around the nucleus, with the remainder of the cytoplasm filled with intermediate filaments. Calibration bar: 2.5 |jm.
A particular problem with this tumor is distinguishing it from epithelioid sarcomas. Both tumors are identical clinically, immunohistochemically, and electron microscopically; however, some investigators believe it is possible to differentiate these two neoplasms based on morphologic features. "*'^°'^-' They suggest that multiple nodules with central necrosis and cells with bland nuclear features simulating a granulomatous process are characteristic of epithelioid sarcoma. Rhabdoid tumors, however, are composed of large pleomorphic cells with prominent nucleoli and characteristic eosinophiiic perinuclear inclusions. We have seen cases of typical epithelioid sarcomas that have the same type of cell characteristically attributed to rhabdoid tumors. For this reason, we feel that it is sometimes difficult to differentiate between these tumors, except in the typical cases. Due to the fact that only two rhabdoid tumors of the skin have been reported to date (reference 16 and the current case), we cannot compare their behavior with that of epithelioid sarcomas; however, both are highly aggressive malignant t u m o r s and should be treated accordingly.
Figure 5. Higher power electron photomicrograph showing the bundling of intermediate filaments (arrow) within the cytoplasm. Also in view are short segments of rough endoplasmic reticulum. Calibration bar: 0.25 |im.
Acknowledgments: Marianne Brown assisted with the immunohistochemistry; Donna Normoyle assisted with the electron microscopic study; Medical Media Services, Veterans Affairs Medical Center, assisted with the light microscopic study; Lori Cohen typed and edited the manuscript; and Dr. Robert Erlandson, Memorial Sloan-Kettering Cancer Center, New York, reviewed the case. .
postulated, but no definitive proof has been establisbed for any of these. In the present case the neoplastic cells stained positively for vimentin, cytokeratin, EMA., actin, desmin, alpha-1-antitrypsin, and alpha-1-antichimotrypsin. Expression of cytokeratin and KMA are thought to denote epithelial differentiation.^" Vimentin, alpha-1antitrypsin, and alpha-1-antichimotrypsin stain tumors of mesenchymal differentiation, although vimentin can also be found in malignant epithelial tumors." Tumors associated with myogenic differentiation are positive for actin and desmin; therefore, the unusual results found in this case, where antibodies against desmin, cytokeratin, and vimentin tested positive, seem to support the possibility that this tumor originates from undifferentiated cells, tjltrastructural features of this tumor include collections of intermediate filaments near the nucleus, which correspond to the hyalin globules seen with the light microscope. These intermediate filaments form bundles
REFERENCES 1.
Haas JE, Palmer NF, Weinberg AG, et al. Ultrastructure of malignant rhahdoid tumor of the kidney. Hum Pathol 1981; 12:646-657.
2.
Kawanishi G, Tamura M, Akiyama K, et al. Rhabdoid tumors of the spermatic cord. Br J Urol 1989; 63: 439^40. Ekfors TO, Heikki JA, Kekomaki M. Malignant rhahdoid tumor of the prostatic region. Virchows Arch [A] 1985; 406:381-388. •
3.
486
Rhabdoid Tumor Sangueza et al.
4.
5. 6.
7.
8.
9.
Small EJ, Gordon GJ, Barrett B. Malignant rhabdoid tumor of the heart in an infant. Cancer 1985; 55: 2850-2853. Blatt J, Russo P, Taylor S. Extrarenal rhabdoid sarcoma. Med Pediatr Oncol 1986; 14:22t-226. Robson DB, Akbarnia BA, deMello D, et al. Malignant rhabdoid tumor of the thoracic spine. Spine t987; 12: 620-624. Bigss PJ, Garaen PD, Powers JM, et al. Malignant rhabdoid tumor of the central nervous system. Hum Pathol 1987; 18:332-337. Kent AL, Mahoney DH, Gresik MV, et al. Malignant rhabdoid tumor of the extremity. Cancer 1987; 60: 1056-1059. Dervan PA, Cahalane SF, Kneasfsey P, et al. Malignant rhabdoid tumor of soft tissue: an ultrastructural and immunohistological study of a pelvic tumor. Histopathology 1987; tl:183-t90.
15.
16.
17.
18.
19.
10.
Harris M, Eyden BP, Joglekar VM. Rhabdoid tumor of the bladder: a histological, ultrastructural and immunohistochemical study. Histopathology 1987; 11: 1083-1092. 11. Parham DM, Peiper SC, Robicheaus G, et al. Malignant rhabdoid tumor of the liver. Arch pathol Lab Med 1988; 112:61-64. 12. Jakate SM, Marsden HB, Ingram L. Primary rhabdoid tumor of the brain. Virchows Arch [A] 1988; 412: 393-397. 13. Carter RL, McCarthy KP, Al-Sam SZ, et al. Malignant rhabdoid tumor of the bladder with immunohistochemical and ultrastructural evidence suggesting histiocytic origin. Histophathology 1989; 14:179-190. 14. Tsokos MA, Kourakis G, Chandra RS, et al. Malignant
20.
21.
22.
23.
rhabdoid tumor of the kidney and soft tissues. Arch Pathol Lab Med 1989; 113:115-120. Lynch HT, Shurin SB, Dahms BB, et al. Paravertebral malignant rhabdoid tumor in infancy. Cancer 1983; 52: 290-296. Dabbs DJ, Park HK. Malignant rhabdoid skin tumor: an uncommon primary skin neoplasm. Ultrastructural and immunohistochemical analysis. J Cutan Pathol 1988; 15:109-115. Tsuneyoshi MA, Daimaru Y, Hashimoto H, et al. Malignant soft tissue neoplasm with the histologic features of renal rhabdoid tumors. Hum Pathol t985; 16:12351242. Molenaar WM, Dejon B, Dam-Meiring A, et al. Epithelioid sarcoma or malignant rhabdoid tumor of soft tissue? Epithelioid immunophenotype and rhabdoid karyotype. Hum Pathol 1989: 21:347-351. Zanetti G, Giangaspero F. Rhabdomyoblastic nature of cytoplasmic inclusions in malignant rhabdoid tumor. Hum Pathol 1982; 13:410. Perrone T, Swanson PE, Twiggs L, et al. Malignant rhabdoid tumor of the vulva: is distinction from epithelioid sarcoma possible? A pathologic and immunohistochemical study. Am J Surg Pathol 1989; 13:848-858. Weeks DA, Beckwith JB, Mierau GW. Rhabdoid tumor: an entity or a phenotype? Arch Pathol lab Med 1989; 113: 113-114. Tsuneyoshi M, Daimaru Y, Hashimoto H, et al. The existence of rhabdoid cells in specified soft tissue sarcomas: histopathological, ultrastructural and immunohistochemical evidence. Virchows Arch [A] 1987; 411: 509-514. Fisher C. Epithelioid sarcoma: the spectrum of ultrastructural differentiation in seven immunohistochemical defined cases. Hum Pathol 1988; 19:265-275.
"Contented." Virginia R. Edwards, Lighthouse Point, Florida. Oil Painting second place. American Academy of Dermatology Art Exhibit, Dallas, Texas 1991. Photograph courtesy of Dermik Laboratories, Inc. 487
