What should you know about cystic keratoacanthoma?

This type of growth may begin as a firm bump and develop a central depression or plug of keratin. It can occur on sun-exposed skin, including the face, ears, backs of the hands, and forearms. A cystic appearance does not establish the diagnosis: inflamed cysts, warts, and squamous cell carcinoma can look similar. Sun-damaged skin is one relevant background factor; you can read about [Sun-Damaged Skin](/conditions/photoaging/). A clinician may examine the lesion with magnification and recommend a biopsy or removal so the cells can be checked.

Arrange a dermatology appointment rather than squeezing, cutting, or repeatedly covering the lump. Take a clear photograph beside a ruler and note when it appeared, how quickly it changed, and whether it bleeds or crusts. Treatment depends on the examination and tissue diagnosis. Options may include [Curettage And Cautery](/treatments/surgical-dermatology/curettage-and-cautery/) or [Surgical Excision](/treatments/surgical-dermatology/excisional-surgery/), which removes the growth with a margin when appropriate.

Seek prompt medical review for a lump that enlarges over weeks, develops a central crater, becomes tender, repeatedly crusts, or bleeds with little contact. Arrange urgent care if bleeding will not stop after firm pressure, or if redness, warmth, swelling, and fever suggest infection. Do not wait for pain: some concerning skin growths are not painful.

Ask whether the lesion needs a biopsy, which procedure is suitable for its location, how the wound will be cared for, and whether nearby sun-damaged skin needs examination.