Primary cutaneous osteosarcoma of the scalp in an immunosuppressed individual: A case report and review of the literature.

We report a case of a 76-year-old man presenting with a 12-month history of a solitary lesion on his scalp. The histopathology was consistent with a grade 2/3 osteosarcoma extending to the subcutis. Full-body imaging excluded any involvement of the underlying bony tissue or solid organ malignancy, thus a diagnosis of primary cutaneous osteosarcoma (PCO) was made. Given the exceedingly rare nature of PCO, we discuss the clinico-pathological features of this case and those previously reported in the literature.