Introduction:

Large cell acanthoma is a rare, benign epidermal neoplasm of unknown aetiology. Because of the ongoing nosological debate, some authors regard it as a separate independent entity, while others classify it as a subtype of other conditions like lentigo, seborrheic keratosis, actinic keratosis, or even Bowen’s disease. Large cell acanthomas are usually solitary lesions located within sun-exposed skin, well-demarcated from surrounding. The diagnosis is always based on histological examination.

Objective:

Presentation of the characteristic clinical, videodermatoscopic, and histopathological features of this rare neoplasm.

Case report:

The paper presents the case of a 76-year-old man who, for several years, had been observing a gradually spreading, yellow-brown lesion with a hyperkeratotic surface, located on the skin of his upper back. Based on histological examination, large cell acanthoma was diagnosed.

Conclusions:

Histological examination plays a crucial role in the differential diagnosis of atypical skin lesions, including large cell acanthoma.