Introduction: leprosy is an endemic disease in Brazil, ranking second worldwide for the number of new cases diagnosed yearly. However, late diagnosis of this disease is still common.
Objective: to alert health professionals to the importance of recognizing the insidious signs of leprosy, both clinical and histopathological, even in the presence of other, more apparent alterations.
Presentation and discussion of the case: a man with skin lesions suggestive of squamous cell carcinoma. On histological examination, besides the carcinoma, there were aggregates of foamy macrophages full of acidfast bacilli compatible with lepromatous leprosy. A more detailed physical examination by a multidisciplinary team from a national reference center also revealed skin with a diffuse infiltrated appearance and supraciliary madarosis, alterations not noticed in the first evaluation at another service.
Final considerations: this case can help clinical professionals and pathologists pay attention to skin alterations that can make it challenging to diagnose leprosy, especially in endemic regions, to enable early diagnosis and reduce the disabilities related to the disease.