Sebaceous Adenoma

What is it?

Sebaceous glands make the skin's natural oil. A sebaceous adenoma is a benign overgrowth of these glands and is common in older dogs. Coonhounds, cocker spaniels and English cocker spaniels, Huskies, Samoyeds, and Alaskan malamutes are most likely to develop them. A similar, smaller change called sebaceous hyperplasia also occurs in old dogs. A malignant form, sebaceous adenocarcinoma, is rare.

What signs should I watch for?

Look for firm, raised, well-defined bumps on the skin, often on the head and usually larger than about 1 cm (0.4 inch). They may be crusted, and some become inflamed, infected, or bleed if scratched or licked. A growth on the edge of the eyelid can irritate the eye, causing squinting or rubbing at the face.

How is it diagnosed and treated?

Your veterinarian may take a fine needle sample, though these growths often contain oily secretions that make the sample less useful, so removal and laboratory examination (histopathology) is often how the diagnosis is confirmed. Surgery is optional for benign growths unless they are bothersome, inflamed, or infected; when needed, it is usually straightforward. A cone can stop licking after a sample or surgery.

Can it be prevented, and what's the outlook?

• There is no known prevention.
• These growths grow where they start and do not tend to spread, but dogs that have one often develop new ones elsewhere.
• Have any new or changing lump checked.