A 63-year-old woman with long-standing psoriasis and decades-long history of methotrexate ingestion presents with a solitary, hard, slightly tender nodule on the hand. A review of her past medical history also revealed extensive phototherapy. The patient was of Irish ancestry, with a very fair complexion, who sunburned easily.
Key point: The appearance of the skin lesion alone should strongly suggest the proper diagnosis: primary cutaneous squamous cell carcinoma.
Treatment: The lesion was excised under histologic control by Moh’s surgery. The resulting large defect was closed via split-thickness skin graft. Radiation therapy might be another treatment option.
Note: Although the patient learned early in life to avoid the sun, she was nonetheless exposed to therapeutic ultraviolet irradiation for many years, as well as to a known tumorigenic immunosuppressive (methotrexate). There is an element of iatrogenic etiology in this case.