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. 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. These abnormalities have not yet been reported in ectopic papillary hidradenomas. Diagnosis
The diagnosis of anogenital papillary hidradenoma lesions, while often suggested based on their clinical presentations, must be differentiated from a wide range of other similarly presenting anogenital lesions such as hemorrhoidal disease, anorectal abscesses, virus-related wart-like lesions, sebaceous cysts, mucous cysts, lipomas, neurofibromas, metastatic carcinomas with papillary histopathology, syringocystoadenocarcinoma papilliferum (i.e. malignant syringocystadenoma papilliferum), syringocystadenoma papilliferum, melanomas, eccrine porocarcinomas, squamous cell carcinomas, nodular lesions in extramammary Paget disease, dermatofibroma, focal areas of mucinosis, colloid milium, and sebaceous adenomas. This differentiation is made by finding that a lesion has the histopathological features typical of papillary hidradenomas. However, some cases diagnosed as ectopic papillary hidradenomas, particularly those occurring in men, have subsequently been found to be syringocystadenoma papilliferums or trichoepitheliomas. Further studies are required to better define the criteria for ectopic papillary hidradenomas. Treatment and prognosis
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. Recurrence of these tumors is rare and usually due to incomplete removal of the primary lesion.
As of 2021, there has been no reported recurrence of ectopic papillary hidradenomas. Prognosis after complete surgical removal of anogenital and ectopic papillary hidradenomas is excellent. Malignant transformation of papillary hidradenomas
Transformations of papillary hidradenomas into malignant forms are extremely rare. Two cases progressed to in situ (malignant cells present in the tumor but have neither metastasized, i.e. spread to distant tissues nor invaded beyond the layer of tissue from where they arose) cancers; two cases appeared to have infiltrated locally but not metastasized; and one case was a rapidly fatal lesion that appeared to be an adenosquamous carcinoma that arose in a papillary hidradenoma. It is not clear that these cases actually represent true progression of papillary hidradenoma into a cancer. See also
Hidroacanthoma simplex
List of cutaneous conditions

References


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