The histopathology of anogenital and ectopic papillary hidradenomas are similar to each other. Immunohistochemistry
Immunohistochemical analyses of anogenital papillary hidradenoma tumors have detected the expression of both the estrogen and progesterone receptors in 18 and the androgen receptor in 4 of 20 cases. In another study of anogenital papillary hidradenomas, expression of the estrogen receptor was restricted to the tumors glandular epithelial cells while the tumors myoepithelial cells expressed tumor protein p63 and alpha-smooth muscle actin protein. Presence of the estrogen and progesterone receptors may underlie the female prevalence of anogenital papillary hidradenomas as well as their development in females only after puberty. The anogenital tumor cells may also express vimentin, various cytokeratin proteins, and in a minority of cases the DNA of human papillomavirus (infection by this virus and the presence of its DNA does not appear involved in the development of papillary hidradenoma). These immunohistochemistry findings have not as yet been reported in atypical papillary hidradenomas. Gene and signaling pathway abnormalities
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 mutated genes include PIK3CA, AKT1, PIK3CA, MAGI1, SYNE1, USP9X, KLNI (also termed CASC5), RNF213, FLCN, PDGFRB, AR (i.e. the androgen receptor gene), BTK, MLL3, KAT6A, BRD3, EP400, TET2, IL6, and IL7R. The PI3K/AKT/mTOR pathway promotes the grow (i.e.
Kim, Sun Bean; Kim, Do Kyung; Byun, Sun Jeong; Park, Ji Hye; Choi, Jin Young; Park, Young Nyun; Kim, Do Young (2015-12-01). "Peliosis hepatis presenting with massive hepatomegaly in a patient with idiopathic thrombocytopenic purpura". Clinical and Molecular Hepatology. 21 (4): 387–392. doi:10.3350/cmh.2015.21.4.387. ISSN 2287-2728. PMC 4712167. PMID 26770928. External links
Merck Manual: Hepatomegaly