Al-Hussaini Maysa, Hirschowitz Lynn, McCluggage W Glenn
Department of Pathology, King Hussein Cancer Centre, Amman, Jordan.
Int J Gynecol Pathol. 2008 Apr;27(2):236-42. doi: 10.1097/PGP.0b013e31815aca67.
Malignant rhabdoid tumors are rare childhood neoplasms which occur most commonly in the kidneys, soft tissue, and central nervous system. They are characterized by cells with eccentric vesicular nuclei, prominent nucleoli, and abundant eosinophilic cytoplasm. Recently, it has been demonstrated that malignant rhabdoid tumors in childhood are characterized by biallelic deletion or mutation involving the SMARCB1/INI1 gene on chromosome 22. These molecular events result in loss of immunohistochemical expression of INI1. Neoplasms with a similar morphology occur in adults, either in pure form or associated with a parent tumor. It is controversial whether such neoplasms in adults are related to childhood malignant rhabdoid tumor or whether a rhabdoid morphology represents a nonspecific phenotype which can occur in a variety of neoplasms. In this study, we stained a series of adult uterine neoplasms with a prominent component of rhabdoid cells with the Baf 47 antibody which detects INI1; we aimed to ascertain whether these are related to childhood malignant rhabdoid tumor. Neoplasms included were an undifferentiated sarcoma consisting entirely of rhabdoid cells, 2 carcinosarcomas with a mesenchymal component composed entirely of rhabdoid cells, and 3 uterine tumors resembling ovarian sex cord tumor with rhabdoid cells. In all cases, there was positive nuclear staining of the rhabdoid cells with Baf 47, suggesting an absence of gene deletion or mutation and that these neoplasms are not related to childhood malignant rhabdoid tumor. In adults, we suggest that a diagnosis of malignant rhabdoid tumor should not be made without genetic confirmation or loss of immunohistochemical expression of Baf 47. In the absence of these, an attempt should be made to classify such tumors on the basis of any associated parent neoplasm and/or immunohistochemical or ultrastructural evidence of specific differentiation. We reviewed uterine neoplasms with a rhabdoid phenotype.
恶性横纹肌样瘤是罕见的儿童肿瘤，最常发生于肾脏、软组织和中枢神经系统。其特征是细胞具有偏心泡状核、明显的核仁以及丰富的嗜酸性细胞质。最近有研究表明，儿童恶性横纹肌样瘤的特征是22号染色体上的SMARCB1/INI1基因发生双等位基因缺失或突变。这些分子事件导致INI1免疫组化表达缺失。形态相似的肿瘤也见于成人，可为单纯形式或与母瘤相关。成人的这类肿瘤是否与儿童恶性横纹肌样瘤相关，或者横纹肌样形态是否代表一种可出现在多种肿瘤中的非特异性表型，目前仍存在争议。在本研究中，我们用检测INI1的Baf 47抗体对一系列以横纹肌样细胞为主要成分的成人子宫肿瘤进行染色；我们旨在确定这些肿瘤是否与儿童恶性横纹肌样瘤相关。纳入的肿瘤包括完全由横纹肌样细胞组成的未分化肉瘤、2例间叶成分完全由横纹肌样细胞组成的癌肉瘤以及3例类似卵巢性索肿瘤伴横纹肌样细胞的子宫肿瘤。在所有病例中，横纹肌样细胞的细胞核均被Baf 47抗体阳性染色，提示不存在基因缺失或突变，且这些肿瘤与儿童恶性横纹肌样瘤无关。在成人中，我们建议在没有基因确认或Baf 47免疫组化表达缺失的情况下，不应诊断为恶性横纹肌样瘤。在缺乏这些情况时，应尝试根据任何相关的母瘤和/或特定分化的免疫组化或超微结构证据对这类肿瘤进行分类。我们回顾了具有横纹肌样表型的子宫肿瘤。
