Perivascular Epithelioid Cell Tumor (PEComa) Affecting the Knee in a Seven-Year-Old Girl: A Case Report.

Perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors composed of cells with epithelioid and spindle morphology, which grow around blood vessels. PEComas of soft tissue are usually reported in adults, with a rare incidence in the pediatric population, especially in young children and in the soft tissue of the limb. We report a case involving a healthy seven-year-old girl who presented with a painless prominence in front of the tibial tubercle. Radiological imaging revealed an encapsulated, lobulated mass that simulated a lipoma. After surgical excision, the microscopic examination and histopathological analysis of the surgical specimen confirmed the diagnosis of benign PEComa. Our case underscores the importance of considering PEComa in the differential diagnosis of pediatric soft tissue masses in children, whose presentation may vary from benign to malignant. Surgical treatment is the preferred approach for benign PEComas.