Rhabdoid Features in Leiomyosarcoma of Soft Tissue: With Special Reference to Aggressive Behavior

Abstract

The presence of rhabdoid cells has been reported in various types of malignant neoplasms and has been determined to be a predictor of aggressive behavior of neoplasms regardless of tumor histogenesis. One hundred and thirteen cases of leiomyosarcoma, selected from 1800 soft tissue sarcomas, were reviewed on hematoxylin and eosin sections, and immunohistochemical staining when available, and seven cases with rhabdoid features were retrieved. Clinicopathologic differences were analyzed to compare between cases with rhabdoid features and those without rhabdoid features. In the seven cases with rhabdoid features, two were intra-abdominal, and the others arose in external soft tissues including muscle, subcutis, and cutis. Patient age ranged from 33 to 84 years, three were female, and four were male. Tumor size ranged from 3 to 22 cm. Clinical evidence showed no differences from those cases without rhabdoid features. Histologically, one of the abdominal cases was epithelioid leiomyosarcoma. Two of the 7 cases were better subclassified as pleomorphic leiomyosarcoma, in which rhabdoid cells are diffusely scattered. In cases other than those with pleomorphic leiomyosarcomas, foci of anaplastic areas were observed, and collections of rhabdoid cells were present in those areas. Immunohistochemical examination of the cases confirmed myogenic differentiation, and showed rhabdoid cells being positive for vimentin and desmin in the inclusion bodies, and diffusely so for muscle actin in the cytoplasm. After dividing all the cases of leiomyosarcoma by their location, prognostic analysis was performed. Leiomyosarcoma of external soft tissue with rhabdoid cells showed a tendency for poorer prognoses than cases without rhabdoid features. On the contrary, retroperitoneal cases did not. This study indicates that rhabdoid features are associated with aggressive biological behavior in leiomyosarcoma of the external soft tissue.

INI1 expression is retained in composite rhabdoid tumors, including rhabdoid meningiomas

“…The secondary rhabdoid phenotype is most often found in neoplasms of adults and has been encountered in a variety of parent neoplasms, including carcinomas, melanomas, sarcomas, desmoplastic small round cell tumors, neuroblastomas, meningiomas, and gliomas. 7,[25][26][27][28][29][30][31][32][33][34] Occasionally, the parent tumor is not immediately recognizable so that a specific diagnosis is not attainable, beyond that of a highgrade malignant neoplasm. Previously referred to as composite extrarenal rhabdoid tumors, the 'extrarenal' portion is no longer appropriate, given the recent recognition of a rhabdoid variant of renal cell carcinoma.…”

Renal Cell Carcinoma with Rhabdoid Features: Report of a Rare Case Diagnosed on Endobronchial Ultrasound-Guided Fine Needle Aspiration

“…The differential diagnosis is broad, because neoplasms with rhabdoid features include primary adenocarcinomas from the gastrointestinal system, genitourinary system, respiratory system, central nervous system, and malignant melanoma (2,3,17,26). In addition, some soft tissue neoplasms such as epithelioid sarcomas and synovial sarcoma also have rhabdoid features (19,25). In this case, the cytological features were highly suggestive of metastasis from the renal neoplasm when combined with imaging studies and clinical history.…”

Malignant melanoma with a rhabdoid phenotype exhibiting numerous solid tumor masses: A case report

“…Thereafter, numerous cases of MRT arising from extra-renal sites including the liver (10,11), brain (10,11), skin (11) and soft tissue (10-13) have been reported. Subsequent studies revealed the rhabdoid cells have also been seen in other tumors, such as some carcinomas (14,15), sarcomas (16)(17)(18), in the central nervous system (19) and malignant melanoma (6,7). The rhabdoid features are thought to represent a common dedifferentiated end point for a variety of neoplasms.…”

“…One explanation is that this discrepancy might be attributed the differences of the specificities of the antibodies used. Furthermore, this variability in immunohistochemical features is frequent among the rhabdoid features which represent a common dedifferentiated end point for a variety of neoplasms (3)(4)(5)(6)(7)(15)(16)(17). Further molecular and cytogenetic studies of the differentiation and the dediffer-entiation of the neoplasm are warranted.…”