ABSTRACT Pseudomyogenic hemangioendothelioma (PMHE) is a rare, low‐grade vascular neoplasm that presents cutaneously as erythematous papules or nodules. Diagnosis is challenging, as PMHE can mimic more common benign dermatological conditions and shares histological similarities with high‐grade tumors, particularly epithelioid sarcoma. We present the case of an 18‐year‐old male with a two‐year history of a tender, indurated, dark brown subcutaneous plaque on his right upper thigh with histopathologic features consistent with PMHE. Genetic testing revealed a novel gene fusion, NEDD9::FOSB , which has not previously been reported in the literature, adding to the current genetic understanding of PMHE, and warrants further exploration as a potential therapeutic target.
Sampath et al. (Thu,) studied this question.