Giant basal cell carcinoma in a non-sun exposed area with four years follow-up: a case report

Basal cell carcinoma (BCC) is a low-grade malignant tumor that if properly managed has an excellent prognosis. Development of BCC outside the skin areas exposed to sun rays is infrequent. Giant BCC is a rare entity, especially in unexposed areas of the body. It carries a considerable implication on patients' quality of life because of the risk of being a source of infection that may progress to severe sepsis and/or metastasis. An old female presented with a long-standing solitary lesion measuring 7.5x6 cm overlaying the lumber 4-5 vertebral region about 2.5 cm from the line of the sacral promontory. No lymph nodes or distant metastases were detected. For many years, it was misdiagnosed by other physicians as eczema, psoriasis, and fungal infection and accordingly failed to respond to treatment. A histopathological examination of lesional punch biopsy assured the diagnosis of giant superficially spreading BCC. The lesion was excised with a circumferential safety margin of about 5 mm. During the follow-up period of 4 years, no recurrence was detected. Despite being a long-standing Giant basal cell carcinoma (GBCC) in a sun-hidden skin area, the growth behaved as a locally malignant lesion without metastasizing. A wide local surgical excision of the GBCC with 5 mm safety margins was feasible, safe, and with a good aesthetic outcome. Importantly, family practitioners should avoid such missed cases through accuracy in their diagnosis and early referral of any atypical cases to a dermatologist.