A Case of Pseudomyogenic Hemangioendothelioma Clinically Mimicking Whitlow With Subsequent Cutaneous Metastasis

A 30-year-old male developed bloody nodules on the fingertips that clinically mimicked whitlow. Biopsy revealed a vascular tumor showing a sheet-like proliferation of large spindle cells and polygonal atypical cells with pleomorphic nuclei and abundant eosinophilic cytoplasm, including rhabdoid cells. Immunohistochemical analysis demonstrated positive staining for CD31, FOSB, AE1/AE3, ERG, INI-1, and BRG, whereas negative staining for CAMTA1, confirming the diagnosis of pseudomyogenic hemangioendothelioma. Digital amputation was performed, but 2 years later, a solitary reddish nodule appeared on the forearm, and histopathological examination revealed features similar to those of the primary digital lesion. Pseudomyogenic hemangioendothelioma presents with various clinical features; however, nodules with a whitlow-like appearance are rare. In addition, this type of tumor is a low-grade malignancy, and rarely metastasizes to lymph nodes or distal sites. Skin metastasis of pseudomyogenic hemangioendothelioma is extremely rare.