Abstract:
Muir-Torre syndrome represents a rare autosomal dominant familial cancer predisposition disorder defined by the occurrence of cutaneous sebaceous tumors and an internal malignancy, most commonly gastrointestinal carcinoma. Most examples of hereditary non-polyposis cancer syndrome (Lynch syndrome), including the Muir-Torre syndrome, are associated with microsatellite instability (MSI) and germline mutations in mismatch repair genes-most commonly MLH1 or MSH2. We present a 58-year-old man with Muir-Torre syndrome and a large retroperitoneal mass (14.3 cm in greatest dimension) encompassing the left adrenal gland. Sections showed a cellular malignant tumor composed of spindle cells with a high mitotic index and lacking morphologic evidence of adipocytic differentiation. It was weakly reactive for smooth muscle actin (SMA) and negative for desmin, CD117, CD31, CD34, S100 protein and pan-cytokeratin. Further immunohistochemical analysis revealed intact expression of MLH1 but loss of MSH2 in tumor nuclei. Compared to non-neoplastic tissue, the tumor showed MSI in five of seven dinucleotide markers. Fluorescence in situ hybridization (FISH) failed to reveal 12q15 amplification, effectively excluding dedifferentiated liposarcoma as a diagnostic consideration. This is a rare case of a patient with Muir-Torre syndrome who developed a related high-grade undifferentiated pleomorphic sarcoma as the associated internal malignancy.
摘要:
Muir-Torre综合征代表一种罕见的常染色体显性家族性癌症易感性疾病,其定义为皮肤皮脂腺肿瘤和内部恶性肿瘤的发生。最常见的胃肠道癌。大多数遗传性非息肉病癌综合征(林奇综合征)的例子,包括Muir-Torre综合征,与错配修复基因中的微卫星不稳定性(MSI)和种系突变有关-最常见的是MLH1或MSH2。我们介绍了一名58岁的男性,患有Muir-Torre综合征和一个大的腹膜后肿块(最大尺寸为14.3厘米),包括左肾上腺。切片显示细胞恶性肿瘤由梭形细胞组成,具有高的有丝分裂指数,缺乏脂肪细胞分化的形态学证据。它对平滑肌肌动蛋白(SMA)的反应性弱,对结蛋白呈阴性,CD117、CD31、CD34、S100蛋白和泛细胞角蛋白。进一步的免疫组织化学分析显示MLH1完整表达,但肿瘤核中MSH2丢失。与非肿瘤组织相比,肿瘤在七个二核苷酸标记中的五个中显示MSI。荧光原位杂交(FISH)未能显示12q15扩增,有效排除去分化脂肪肉瘤作为诊断考虑。这是一例罕见的Muir-Torre综合征患者,其发展为相关的高级未分化多形性肉瘤作为相关的内部恶性肿瘤。