Trichoepithelioma and trichoblastoma are both benign skin tumors which can occur in pet rabbits. They can resemble malignant basal cell tumors (carcinomas), so it is important to distinguish which type is present.

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These tumors originate from the basal cells of hair follicles. They are rare in rabbits with the majority being benign. They tend to have a cystic appearance, can rupture and can appear anywhere on the skin surface of the rabbit.

Trichoblastomas also originate from hair follicles, from trichoblast cells and are sometimes seen in rabbits but are very common in guinea pigs. They appear as raised masses on or under the dermis of the skin and are also benign in nature.

Any rabbit can get these types of tumors, but as rabbits get older, they are more likely to develop tumors.

Different types of skin tumor look very similar. Your veterinarian may first take some cells from the tumor to look at under a microscope and see what type of cells are present to make a diagnosis. This is not painful for your rabbit and will usually be performed conscious or under a small amount of sedation. Alternatively, they may recommend surgical removal of the tumor followed by laboratory testing (histology).

With any skin tumor, surgical removal and testing by histology to determine the exact diagnosis is usually the best option, especially if the whole tumor has been removed and if it is likely to return. Although both trichoblastomas and trichoepitheliomas are benign in rabbits they can cause irritation and may rupture, and can also resemble malignant tumors, so it is best to discuss surgical removal with your veterinarian. Your veterinarian will aim to remove the tumor with margins of at least 1 cm to try to ensure it is all removed.

There is always the possibility of return, but if a trichoblastoma or trichoepithelioma is removed entirely then reoccurrence is unlikely. These types of tumors don’t spread locally or metastasize and spread through the blood, so surgical removal is usually curative.

If you see or feel a skin tumor on your rabbit or are worried in anyway, take your rabbit to a rabbit savvy veterinarian so they can perform a clinical examination and discuss diagnostics and potential treatments with you. There are several types of malignant (cancerous) skin tumor that rabbits can get so if in doubt, get it checked out!