Cytopathologic features of epithelioid inflammatory myofibroblastic sarcoma with correlation of histopathology, immunohistochemistry, and molecular cytogenetic analysis.

Epithelioid inflammatory myofibroblastic sarcoma (E-IMS) is a recently established rare variant of inflammatory myofibroblastic tumor. It is characterized by a distinctive constellation of clinical, pathological, and molecular features, including a nearly exclusive intraabdominal location, strong male predilection, aggressive clinical course, predominance of epithelioid tumor cells, and Ran-binding protein 2 (RANBP2)-anaplastic lymphoma kinase (ALK) fusion in the majority of cases. To the authors' knowledge, the cytologic features of E-IMS have not been described to date. Cases of E-IMS that had corresponding cytology were searched. Six cytology samples (1 fine-needle aspiration sample, 2 imprint samples, and 3 effusion fluids) containing tumor cells were identified in 5 patients with E-IMS. The cytomorphology included large monotonous epithelioid cells arranged in loose aggregates or singly, with admixed myxoid stroma, and an inflammatory background rich in neutrophils. The tumor cells had a large, round, eccentric nucleus with vesicular chromatin, prominent nucleoli, and moderate amounts of pale cytoplasm. Delicate thin-walled branching vessels traversing tumor aggregates was a prominent feature in a fine-needle aspiration sample. Immunohistochemically, ALK was positive in all 5 tumors, with a nuclear membranous staining pattern noted in 3 cases and a cytoplasmic pattern observed in the other 2 cases. ALK rearrangement was confirmed in all 5 tumors by molecular genetic studies. The cytologic features of E-IMS recapitulate its histologic characteristics. E-IMS merits inclusion in the differential diagnosis of any intraabdominal, large epithelioid cell neoplasm. Confirmation of ALK rearrangement is advisable because patients may benefit from targeted therapies.

Lee JC ，Wu JM ，Liau JY ，Huang HY ，Lo CY ，Jan IS ，Hornick JL ，Qian X ... -  《-》

Epithelioid inflammatory myofibroblastic sarcoma: An aggressive intra-abdominal variant of inflammatory myofibroblastic tumor with nuclear membrane or perinuclear ALK.

Mariño-Enríquez A ，Wang WL ，Roy A ，Lopez-Terrada D ，Lazar AJ ，Fletcher CD ，Coffin CM ，Hornick JL ... -  《-》

Epithelioid inflammatory myofibroblastic sarcoma: a clinicopathological, immunohistochemical and molecular cytogenetic analysis of five additional cases and review of the literature.

Yu L ，Liu J ，Lao IW ，Luo Z ，Wang J ... -  《Diagnostic Pathology》

Pulmonary epithelioid inflammatory myofibroblastic sarcoma with multiple bone metastases: case report and review of literature.

Fu X ，Jiang J ，Tian XY ，Li Z ... -  《Diagnostic Pathology》

Epithelioid inflammatory myofibroblastic sarcoma in abdominal cavity: a case report and review of literature.

Wu H ，Meng YH ，Lu P ，Ning HY ，Hong L ，Kang XL ，Duan MG ... -  《International Journal of Clinical and Experimental Pathology》