Rhabdoid tumor

Roberts, C.W., Galusha, S.A., McMenamin, M.E., Fletcher, C.D., and Orkin, S.H. (2000) Haploinsufflciency of Snf5 (integrase interactor 1) pre-disposes to malignant rhabdoid tumors in mice. Proc. Natl. Acad. Sci. USA 97, 13796-13800. 

Epithelioid MPNST is an extremely rare tumor variant that also has a histologic resemblance to melanoma, as well as metastatic carcinoma, CCS, and extrarenal rhabdoid tumor (Fig. 4.26). As a result, epithelioid MPNST is underrecognized as a diagnostic entity. 

Some primary tumors of the soft tissues do not fit neatly into one of the foregoing categories. Malignant extra-renal rhabdoid tumor, chordoma, extraosseous myxoid chondrosarcoma (chordoid sarcoma), extraskeletal osteosarcoma, and selected liposarcoma and angiosarcoma variants are included in this group. 

FIGURE 4.33 The histologic image of extrarenal malignant rhabdoid tumor features large cells with eosinophilic cytoplasm, eccentric vesicular nuclei, and prominent nucleoli. 

Tumors that are histologically identical to malignant rhabdoid tumor of the kidney in children may be encountered in a variety of extrarenal sites in adults, including the soft tissues." The hallmarks of these neoplasms are hyaline paranuclear cytoplasmic eosinophilic inclusions eccentric, rounded nuclei with vesicular chromatin prominent nucleoli (Fig. 4.33) and a complex immunophenotype. 

Extrarenal rhabdoid tumors (ERTs) often show epithelial differentiation, and some may be difficult—if not impossible—to separate diagnostically from such entities as proximal-type epithelioid sarcoma. " INIl, a protein encoded by a gene at chromosome 22qll.2, is involved in chromatin remodeling it is usually absent in both ERT and proximal epithelioid sarcoma, as well as conventional (distal) epithelioid sarcoma. The majority of tumors in each category also show... 

FIGURE 4.37 Keratin in rhabdoid tumor, raising diagnostic concern for another type of soft tissue sarcoma or metastatic carcinoma. 

Fanburg-Smith JC, Hengge M, Hengge UR, et al. Extrarenal rhabdoid tumors of soft tissue A clinicopathologic and immunohistochemical study of 18 cases. Ann Diagn Pathol. 1998 2 351-362. 

Saito T, Oda Y, Itakura E, et al. Expression of intercellular adhesion molecules in epithelioid sarcoma and malignant rhabdoid tumor. Pathol Int. 2001 51 532-542. 

Kodet R, Newton Jr WA, Sachs N, et al. Rhabdoid tumors of soft tissues A clinicopathologic study of 26 cases enrolled on the Intergroup Rhabdomyosarcoma Study. Hum Pathol. 1991 22 674-684. 

Shiratsuchi H, Oshiro Y, Saito T, et al. Cytokeratin subunits of inclusion bodies in rhabdoid cells Immunohistochemical and clinicopathological study of malignant rhabdoid tumor and epithelioid sarcoma. Int J Surg Pathol. 2001 9 37-48. 

Argenta PA, Thomas S, Chura JC. Proximal-type epithelioid sarcoma vs. malignant rhabdoid tumor of the vulva A case report, review of the literature, and argument for consolidation. Gynecol Oncol. 2007 107 130-135. 

Oda Y, Tsuneyoshi M. Extrarenal rhabdoid tumors of soft tissue Clinicopathological and molecular genetic review and distinction from other soft-tissue sarcomas with rhabdoid features. Pathol Int. 2006 56 287-295. 

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. 

Izumi T, Oda Y, Hasegawa T, et al. Prognostic significance of dysadherin expression in epithelioid sarcoma and its diagnostic utility in distinguishing epithelioid sarcoma from malignant rhabdoid tumor. Mod Pathol. 2006 19 820-831. 

The ability of melanoma to simulate the appearance of various soft tissue sarcomas is also well documented. These include malignant peripheral nerve sheath tumors, gastrointestinal stromal tumors, epithelioid angiosarcoma, rhabdoid tumors, osteosarcomas, and primitive neuroectodermal tumors, to name a few. The detailed immunophenotypic properties of those lesions are provided elsewhere in this book. However, none of them manifests reactivity for gplOO-related melanocytic markers or tyrosinase, making those markers essential to the differential diagnostic process. 

Malignant rhabdoid tumors of the kidney were described in 1978 by Beckwith and Palmer as highly malignant tumors of infants and children initially thought to represent a variant of Wilms tumor. Similar neoplasms were described in extrarenal sites and in adults. 

FIGURE 12.30 This primary rhabdoid tumor of lung is composed of large cells with large, globular eosinophilic inclusions. X 400. 

Those that resemble rhabdoid tumors in the kidney but occur in non-renal sites are frequently designated as pseudorhabdoid tumors. They have a diverse immuno-histochemical phenotype,i ° although the majority of them express vimentin and many coexpress vimentin and keratin. 

FIGURE 12.31 The globular inclusions in this primary rhabdoid tumor of lung show intense immunostaining for vimentin. X200. 

S-100 protein, HMB-45, and light chain immunoglobulin (evaluated in 1 case). In this author s experience with 6 cases primary in the lung, 5 showed immunostaining for vimentin (Fig. 12.31) and 1 showed coexpression of vimentin and keratin. Miyagi and associates described 3 cases of primary lung rhabdoid tumor, all associated with an adenocarcinoma. The authors concluded that the rhabdoid cells in these cases represented dedifferentiated components of an adenocarcinoma. 

Small EJ, Gordon GJ, Dahms BB. Malignant rhabdoid tumor of the heart in an infant. Cancer. 1985 55 2850-2853. 

Balaton AJ, Vaury P, Videgrain M. Paravertebral malignant rhabdoid tumor in an adult A case report of immunocytochemi-cal study. Pathol Res Pract. 1987 182 713-718. 

Dervan PA, Cahalane SF, Kneafsey P, et al. Malignant rhabdoid tumor of soft tissue An ultrastructural and immunohistological study of a pelvic tumour. Histopathol. 1987 11 183-190. 

Parham DM, Peiper S, Robicheaux G, et al. Malignant rhabdoid tumor of the liver Evidence for epithelial differentiation. Arch Pathol Lab Med. 1988 112 61-64. 

Uchida H, Yokoyama S, Nakayama I, et al. An autopsy case of malignant rhabdoid tumor arising from soft parts in the left inguinal region. Acta Pathol Jpn. 1988 38 1087-1096. 

Patron M, Palacious J, Rodriguez-Peralto JL, et al. Malignant rhabdoid tumor of the tongue A case report with immunohistochemical and ultrastructural findings. Oral Surg Oral Med Oral Path. 1988 65 67-70. 

MRT (atypical teratoid/rhabdoid tumor) frequently demonstrates deletion and mutation of the hSNF5/INIl gene, with decreased or absent INIl protein expression. An antibody to INIl can be used to assess INIl loss, characterized by absence of immunoreactivity in contrast to functional INIl with positive immunoreactivity in normal tissues and other neoplasms." Like MRT of the kidney and extrarenal soft tissues, atypical teratoid/rhabdoid tumors of the central nervous system showed absence of nuclear staining for INIl in a recent study." 3i... 

FIGURE 17.26 Malignant rhabdoid tumor consists of sheets of round cells with vesicular nuclei, prominent nucleoli, and variable amounts of eosinophilic cytoplasm with occasional large cytoplasmic eosinophilic globules (hematoxylin-eosin, x200). 

Presence of WTl staining and the EWS-WTl gene fusion distinguish DSRCT from malignant rhabdoid tumor, which is another polyphenotypic small cell malignant neoplasm. 

FIGURE 17.28 Vimentin displays cytoplasmic reactivity in malignant rhabdoid tumor (immunoperoxidase, x400). 

FIGURE 17.33 Absence of staining for INI protein correlates with deletion and mutation of the hSNFS/INII gene in central nervous system, malignant rhabdoid tumor (immunoperoxidase, x400). 

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