Mammary fibroadenoma in rats (most common subcutaneous tumor; up to 8–10 cm, both sexes)
Source: Merck Veterinary Manual (merckvetmanual.com), a copyrighted professional veterinary reference. Per COPYRIGHT_POLICY §3, the points below are paraphrased derived fact summaries: numerical values and proper nouns are preserved from the source, but sentences are rewritten and not quoted verbatim.
Claims
*[Paraphrased derived summary — non-Open-Access source.]* The most common subcutaneous tumour in rats is the mammary fibroadenoma; mammary tissue extends widely so tumours can appear anywhere from the neck to the groin, reach 8–10 cm across, and occur in both sexes.