Dehner Carina A, Pearson Hadley, Almohsen Shahd S, Lo Ying-Chun, Thangaiah Judith Jebastin, Torres-Mora Jorge, Guo Ruifeng Ray, Baker Jonathan C, Folpe Andrew L, Alomari Ahmed K, Dickson Brendan C, Billings Steven D, Michal Michael, Demicco Elizabeth G, Fritchie Karen J, Chrisinger John S A
Department of Anatomic Pathology and Laboratory Medicine, Indiana University, Indianapolis, Indiana.
Robert J Tomsich Pathology and Laboratory Medicine Institute, Cleveland Clinic, Cleveland, Ohio.
Mod Pathol. 2024 Dec;37(12):100599. doi: 10.1016/j.modpat.2024.100599. Epub 2024 Aug 23.
Acral fibrochondromyxoid tumor (AFCMT) is a recently described likely benign mesenchymal neoplasm arising in the distal extremities with distinctive histologic features and a recurrent THBS1::ADGRF5 fusion. We studied an additional 37 cases of AFCMT and expanded on the so-far reported clinicopathologic and molecular findings. Tumors occurred in 21 females and 16 males, ranging in age from 17 to 78 years (median age: 47), and solely involved the hands (24/37, 65%) or feet (13/37, 35%). Histologic examination revealed well-delineated uni- or multinodular tumors with prominent vasculature-rich septa and bland, chondrocyte-like tumor cells set within abundant chondromyxoid stroma. Immunohistochemical studies showed that tumor cells were positive for CD34 (25/27; 93%) and ERG (27/27; 100%), whereas negative for S100 protein (0/31). Molecular analysis revealed evidence of a THBS1::ADGRF5 fusion in 17 of 19 (89%) successfully tested tumors. Clinical follow-up was available in 8 cases (median: 97 months), with multiple local recurrences in 1 case at 276, 312, and 360 months. We conclude that AFCMT is a distinct entity with reproducible morphologic, immunohistochemical, and molecular genetic features that should be differentiated from other similar appearing acral mesenchymal neoplasms.
肢端纤维软骨黏液样肿瘤（AFCMT）是一种最近被描述的可能为良性的间叶性肿瘤，发生于四肢远端，具有独特的组织学特征及反复出现的THBS1::ADGRF5融合基因。我们研究了另外37例AFCMT，并扩展了迄今报道的临床病理及分子学发现。肿瘤发生于21名女性和16名男性，年龄范围为17至78岁（中位年龄：47岁），仅累及手部（24/37，65%）或足部（13/37，35%）。组织学检查显示肿瘤界限清楚，呈单结节或多结节状，有明显的富含血管的间隔，在丰富的软骨黏液样基质内可见温和的、软骨样肿瘤细胞。免疫组织化学研究显示肿瘤细胞CD34阳性（25/27；93%）、ERG阳性（27/27；100%），而S100蛋白阴性（0/31）。分子分析显示，在19例成功检测的肿瘤中有17例（89%）存在THBS1::ADGRF5融合基因。8例有临床随访资料（中位随访时间：97个月），1例在276、312和360个月时出现多次局部复发。我们得出结论，AFCMT是一种具有可重复的形态学、免疫组织化学及分子遗传学特征的独特实体，应与其他外观相似的肢端间叶性肿瘤相鉴别。
