Pseudoepitheliomatous Hyperplasia of the Medial Thigh with Dystrophic Calcification and Metaplastic Ossification: A Case Report.

Pseudoepitheliomatous hyperplasia (PEH) is a benign, reactive epidermal proliferation that may histologically mimic squamous cell carcinoma (SCC) due to its pseudo-infiltrative growth pattern. While typically associated with chronic inflammation, trauma, or infection, it is considered to be benign and does not warrant oncological management. Here, we present the case of a 71-year-old African American female with morbid obesity among other comorbidities who presented with a painful, ulcerated right medial thigh mass of 10 years' duration. The patient, a nursing home resident, reported significant localized pain upon presentation. Imaging revealed a large soft-tissue mass with calcification. Biopsy revealed ulcerated skin and extensively fibrosed subcutaneous tissue exhibiting dystrophic calcification, ossification, and granulation tissue, without features of malignancy. Final pathology confirmed PEH. Following the biopsy and confirmation of the benign nature of the lesion, the patient's management focused on conservative wound care and pain control, successfully avoiding the morbidity of radical surgical resection. This case underscores the diagnostic challenge in differentiating PEH from SCC and highlights the importance of making a clear diagnosis to provide great patient care and avoid unnecessary treatments that carry risk.