Pseudomyogenic Hemangioendothelioma of Bone Initially Managed as Slipped Capital Femoral Epiphysis: A Case Report

Pseudomyogenic hemangioendothelioma is a rare, recently described neoplasm that usually presents as multifocal lesions in a single extremity. The disease has demonstrated a high propensity for infiltrative growth and local recurrence but limited metastatic potential. Variations of histological appearance and immunohistochemical signatures have been described, but typically involve spindle or polygonal cells with nuclear atypia and neutrophilic infiltration. Here we present a case report of an 8-year-old female who presented with hip pain that was initially diagnosed and managed as a slipped capital femoral epiphysis (SCFE). Subsequent evaluation led to the diagnosis of pseudomyogenic hemangioendothelioma of bone. Due to the degree of osseous destruction, described patterns of local recurrence, and metastatic potential of this neoplasm, a wide resection with endoprosthetic reconstruction of the proximal femur was performed. This case highlights the importance of due diligence in the diagnoses of SCFE and bone tumors in young patients with abnormalities of the proximal femur, including consideration of the need for biopsy.