[7] Typically, papillary hidradenomas are solitary, slow-growing, small tumors that may have been present for months to many years before the time of diagnosis.

[8] Smaller studies on one or a few females with anogenital papillary hidradenomas found that the tumors commonly presented as asymptomatic, well-confined, skin-colored, red, or bluish nodules[14] in women of Caucasian origin between the ages of 25–66 years.

[4] Ectopic papillary hidradenomas in women have been reported to occur on the scalp, eyelid, cheek, forehead, face, ear canal, and back.

[18] Microscopic histopathological analyses of papillary hidradenoma tumors typically reveal a nodule in the dermis, i.e. layer of skin between the epidermis and subcutaneous tissue.

The glandular epithelial cells appear to be excessively proliferating in the ducts leading to the epidermis and show oxyphilic changes, (i.e. cytoplasm filled with large mitochondria, glycogen, and ribosomes) while the myoepithelial cells often appear clear cell-like, i.e. have uncolored cytoplasm when stained with hematoxylin and eosin.

Several studies have reported the presence in anogenital papillary hidradenoma tumor cells of mutations in one or multiple genes that lead to the production of proteins that directly or indirectly stimulate the PI3K/AKT/mTOR intracellular signaling pathway.

The PI3K/AKT/mTOR pathway promotes the grow (i.e. proliferation) and survival of cells and is abnormally activated in, and appears to contribute to the development and or progression of, a wide range of tumors.

[21] While further studies are needed, these findings suggest that the cited mutations lead to stimulation of the PI3K/AKT/mTOR pathway and thereby promote the development and/or progression of anogenital papillary hidradenoma in the majority of cases.

[9][23] However, some cases diagnosed as ectopic papillary hidradenomas, particularly those occurring in men, have subsequently been found to be syringocystadenoma papilliferums or trichoepitheliomas.

[13] The treatment of choice for anogenital and ectopic papillary hidradenomas, regardless of their locations, is similar: resection of the tumor while preserving the surrounding structures.