Thway Khin, Hamarneh Wael, Miah Aisha B, Fisher Cyril
Royal Marsden Hospital, London, UK
Royal Marsden Hospital, London, UK.
Int J Surg Pathol. 2015 Aug;23(5):377-83. doi: 10.1177/1066896915583996. Epub 2015 Apr 24.
Divergent differentiation occurs in a subset of malignant peripheral nerve sheath tumors (MPNST), but differentiation toward epithelial elements is unusual. MPNST with both heterologous rhabdomyosarcomatous differentiation (malignant Triton tumor), and glandular epithelial differentiation is exceedingly rare, with only 11 cases reported since 1973, and only 1 with histologically proven metastasis. We describe a case occurring in the mediastinum (between the ascending aorta and the main pulmonary artery) of a 40-year-old man with neurofibromatosis type-1. Despite treatment, the tumor metastasized to the right frontal lobe 16 months after diagnosis. Histologically, the primary neoplasm comprised cellular fascicles of atypical spindle cells, with discrete foci of well-formed or more primitive glandular epithelial structures, while the metastases comprised spindle cell sarcoma, including rhabdomyosarcoma, without epithelial elements. We review and discuss the literature on these little characterized neoplasms, including histology and clinical features, adding to the spectrum of documented cases of divergent epithelial differentiation in Triton tumor.
分化差异发生在一部分恶性外周神经鞘瘤（MPNST）中，但向上皮成分的分化并不常见。同时具有异源性横纹肌肉瘤分化（恶性蝾螈瘤）和腺上皮分化的MPNST极其罕见，自1973年以来仅有11例报道，且只有1例有组织学证实的转移。我们描述了1例发生在1名患有1型神经纤维瘤病的40岁男性纵隔（升主动脉和主肺动脉之间）的病例。尽管进行了治疗，肿瘤在诊断后16个月转移至右额叶。组织学上，原发性肿瘤由非典型梭形细胞的细胞束组成，伴有结构良好或更原始的腺上皮结构的离散灶，而转移瘤则为梭形细胞肉瘤，包括横纹肌肉瘤，无上皮成分。我们回顾并讨论了关于这些特征不明的肿瘤的文献，包括组织学和临床特征，丰富了已记录的蝾螈瘤中分化上皮差异病例的范围。
