Boala Paget extramamara (BPEM) difera clinic si histologic de boala Paget a sanului. BPEM afecteaza zonele cutanate in care sunt prezente glande apocrine. Histopatologia BPS: epiderm dezorganizat prin prezenta celulelor Paget izolate sau grupate. Celulele respective raman cantonate in epiderm sau fuzeaza in peretele foliculului pilos si in canalele galactofore (carcinom epidermotrop galactofor). Coexistenta localizarii in epiderm cu cea din canalele galactofore a fost etichetata de Nicolau „sinergism oncogen". Celulele Paget au talie mare, sunt lipsite de punti intercelulare au nucleu monstruos, hipercromatic, excentric si o citoplasma clara abundenta.

Se prezinta doua cazuri de BPEM, unul localizat in regiunea inghino-crurala extins progresiv la toata vulva si altul care interesa numai vulva. In primul caz tabloul histopatologic, comparabil cu cel din BPS, se deosebeste de acesta prin prezenta de celule Paget in glandele apocrine, ductul ecrin si invazia conjunctivului dermic. Invazia carcinomatoasa a dermului este absenta in cel de al doilea caz. BPEM are prognostic mai bun decat BPS (numai 21% din cazuri se insotesc de un adenocarcinom invaziv, mai ales la pacientele cu leziuni multifocale). Carcinogeneza BPEM are loc in glandele apocrine.

Extra-mammary Paget disease (EMPD) differs clinically and pathologically from the mammary Paget disease (MPD). EMPD affects coetaneous regions having apocrine glans. Pathology of MPD: Paget cells grouped or single dezorganizing the epidermis structure. Paget cells remain in epiderm or fuse in the hair follicle wall and in the galactophore channels (galactophore epidermotrop carcinoma). The co-existence of epidermal localization together with the situation in the galactophore channels was labeled by Nicolau as "oncogenic synergism". Paget cells are large, without intercellular bridges, with monstrous nucleus, hyper-chromatic, eccentric and with clear abundant cytoplasm.

Two cases of EMPD are presented. One with localization in the crural region and with a progressive extension to the vulva. The other case was only with vulvar affection. In the first case the pathological examination was similar to the MPD being different by the presence of Paget cells inside apocrine glans, ecrine duct and also invading the dermic tissue. Carcinomatous invasion of the dermis was absent in the second case. EMPD has abetter prognosis that MPD (21% of cases having an invasive adenocarcinoma, greater incidence being encountered in multi - focal patients). EMPD carcinogenesis takes place in the apocrine glands.