Basal Cell Carcinoma in an Unexposed Body Part

Abstract Basal cell carcinoma (BCC), is a skin cancer, frequently arising in sun-exposed areas, but can occur in atypical locations, including the lower limbs with incidence rates ranging from 1.5% to 13.5%. A 40-year-old woman with an asymptomatic dark lesion on her right shin persisting for over 20 years presents with recent growth, itching, intermittent discomfort, skin peeling, and bleeding episodes for 2 weeks. Examination revealed a 4 cm × 3 cm ill-defined, brownish-black ulcero-proliferative lesion. A wide local excision of the lesion was done and histology confirmed a mixed-type BCC with both nodular and superficial patterns. Although BCC primarily manifests in sun-exposed areas, it can develop in less common sites like the lower limbs. This case underscores the necessity of considering BCC in differential diagnoses for unusual skin lesions, irrespective of location. The tumor’s development is influenced by environmental and genetic factors, including the Hedgehog signaling pathway. With a favorable prognosis and high cure rates postsurgery, ongoing follow-up is essential to monitor for recurrence or new lesions. Preventive strategies, including sun protection and regular skin checks, remain crucial, particularly for at-risk populations. This case highlights the rarity of BCC in the lower extremities and emphasizes the importance of vigilance in identifying atypical presentations of skin cancers.