giant pigmented basal cell carcinoma in the inguinal region: a diagnostic challenge at an uncommon site

Background: basal cell carcinoma is the most common skin cancer. it accounts for 80% of all non-melanoma skin cancers. it most commonly occurs in sun-exposed areas. 0.094% of the cases occur in the inguinal region.case presentation: a 70-year-old male presented with swelling in the left inguinal region for 6 months, diagnosed as malignant melanoma based on clinical and cytological features and finally as pigmented basal cell carcinoma by histopathology and immunohistochemistry.conclusion: all pigmented lesions are not melanoma. pigmented basal cell carcinoma is an important differential diagnosis for malignant melanoma irrespective of the site, size, and clinical picture. we take this opportunity to reiterate the chances and reasons for the misdiagnosis of basal cell carcinoma in cytology smears.