Sebaceous horn: a rare clinical image

A sebaceous horn, well known as a keratoacanthoma or cornu cutaneum, is a rare, benign skin tumor. It is characterized by a hard cone-shaped protrusion growth like a horn made up of keratinized material, a protein found in the skin. It appears on sun-exposed areas of the body, such as the face, scalp, or back of the hands. Sebaceous horns typically arise from a base of benign skin conditions like seborrheic keratosis or keratoacanthoma. The horn-like structure is formed as a result of the rapid growth of cells within the tumor. As most sebaceous horns are non-cancerous, they should be evaluated to rule out as they can sometimes be associated with underlying skin malignancies, such as squamous cell carcinoma. Sebaceous horns are less common than sebaceous cysts. A sebaceous horn is not a direct complication of a sebaceous cyst. A sebaceous cyst is a separate entity that forms from a blocked hair follicle or oil gland. It is a closed sac filled with a semi-solid material, typically sebum, dead skin cells, or other debris. While both sebaceous cysts and sebaceous horns involve the sebaceous glands and can occur on the skin, they are distinct entities with different causes, characteristics and advice of treatment is excision with histopathological confirmation.