A case of G－CSF and PTHrP－producing spindle cell squamous cell carcinoma of the right heel

Abstract

Herein, we report a case of spindle cell squamous cell carcinoma (SCC) that produced G－CSF and PTHrP. A 46－year－old woman presented with a 5 cm－sized erythematous mass on her right heel. A skin biopsy revealed spindle cell SCC. The tumor grew rapidly to approximately 15 cm in diameter in three weeks, and the patient developed impaired consciousness caused by PTHrP－induced hypercalcemia. Right femoral amputation was performed to reduce the tumor ; the blood calcium level returned to the normal range, and the patient’s consciousness improved. Adjuvant radiotherapy without chemotherapy was administered at the patient’s request ; however, the tumor grew rapidly, and a high titer of white blood cells was observed due to elevated G－CSF. One course of irinotecan monotherapy was administered ; however, the SCC worsened, and the patient died four months after the initial diagnosis. [Skin Cancer (Japan) 2024 ; 39 : 312－317]