Lesions of anogenital mammary-like glands are rare, and only 44 female cases have been reported. Herein, we describe a particularly rare case of
phyllodes tumor of anogenital mammary-like glands in a 41-year-old male presenting anal
bleeding. Papillectomy was performed. The excised
tumor was circumscribed in shape, and after it was sliced into sections, it was noted that there were leaf-like slits on the surface of cut side. Under the microscope, the
tumor was found to be biphasic, with a bland glandular epithelium and low-to-intermediate cellular stroma, which together created the leaf-like slits. Gynecomastoid
hyperplasia was evident at the periphery. The epithelium showed immuno-activity for ER, PR(focal), AR, and GCDFP-15. The stromal cells showed positive staining for CD34 and
vimentin. The morphology and immunophenotype were similar to benign
phyllodes tumors of breast. To the best of our knowledge, this case report represents the first case of
phyllodes tumor of anogenital mammary-like glands with gynecomastoid
hyperplasia at the periphery in a male patient. To make a diagnosis, we had to differentiate this lesion from
hidradenoma papilliferum of skin appendage,
phyllodes tumor of ectopic prostatic tissue, and other
tumors of anogenital mammary-like glands analogous to the
breast tumor (e.g.,
fibroadenoma phyllodes, periductal stromal
sarcoma, and
spindle cell carcinoma). While
gynecomastia of male breast is usually a result of
hormone imbalance, our patient's
tumor did not seem to be related to peripheral
hormone status in the anogenital mammary-like glands. Nevertheless, because
hormone imbalance has been strongly related to
male breast cancer,
hormone levels may need to be followed in male patients who have this rare malady.
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