Naous Rana
Department of Pathology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
AME Case Rep. 2024 May 9;8:60. doi: 10.21037/acr-23-191. eCollection 2024.
Plexiform fibrohistiocytic tumor (PFH) is a rarely metastasizing slowly growing neoplasm usually affecting children and young adults. The tumor usually has a dermal-subcutaneous location, is poorly circumscribed, and is comprised of a plexiform or multinodular proliferation of a variable admixture of fibroblasts and histiocytoid cells with a distinctive biphasic morphology. Myxoid change in PFH is extremely rare with only five cases of myxoid variant of PFH reported to date in the English literature.
In this case report, the author describes a rare case in a 39-year-old man who had presented with a newly developed right forearm mass. Given the tumor's unusual morphology an extensive immunohistochemical and molecular workup was performed to rule out common superficial myxoid neoplasms and potential mimickers. The overall ancillary findings along with the histomorphologic features and immunoprofile of the entirely excised mass were eventually compatible with myxoid PFH.
Myxoid PFH is a rare or underrecognized entity that can present as a diagnostic pitfall and can lead to an erroneous diagnosis especially if the pathologist is unaware of such entity. In this case report the author sheds light on this unique tumor, myxoid PFH, discusses the pitfalls inherent to its differential diagnosis, and reviews the literature on such a rare phenomenon.
丛状纤维组织细胞瘤（PFH）是一种罕见的、转移缓慢的肿瘤，通常影响儿童和年轻人。该肿瘤通常位于真皮-皮下，边界不清，并由成纤维细胞和组织细胞样细胞的可变混合物呈丛状或多结节状增生组成，具有独特的双相形态。PFH中的黏液样改变极为罕见，迄今为止，英文文献中仅报道了5例PFH黏液样变体病例。
在本病例报告中，作者描述了一例罕见病例，一名39岁男性出现新发生的右前臂肿块。鉴于肿瘤形态异常，进行了广泛的免疫组织化学和分子检查，以排除常见的浅表黏液样肿瘤和潜在的相似肿瘤。最终，整个切除肿块的总体辅助检查结果以及组织形态学特征和免疫表型与黏液样PFH相符。
黏液样PFH是一种罕见或未被充分认识的实体，可能成为诊断陷阱，尤其在病理学家不了解该实体的情况下，可能导致错误诊断。在本病例报告中，作者阐明了这种独特的肿瘤——黏液样PFH，讨论了其鉴别诊断中固有的陷阱，并回顾了关于这种罕见现象的文献。
