Final Diagnosis -- Fibroadenoma of the Vulva
Fibroadenoma of the vulva.
Fibroadenoma of the vulva is an exceptionally rare occurrence. It is a breast like benign biphasic fibroepithelial neoplasm composed of an epithelial glandular component and a stromal component. The neoplasm is of uncertain histogenesis arising either in an ectopic or supernumerary breast tissue or anogenital mammary-like gland (AGMLG) tissue.  Around 50 cases of ectopic benign breast lesions and 20 cases of ectopic malignant breast neoplasms have been reported in the literature. 
The vulval fibroadenoma is seen between 20-80 years of age.  It usually manifests as subcutaneous nodules or a mass. It is commonly solitary, mostly on the labia majora, seldom presents as vulval cysts and very infrequently bilateral. The lesion usually measures 0.8 to 6.0 cm in size. The mass may increase in size significantly during pregnancy or lactation. [4-8]
Hartung described the first mammary type tissue in the vulva in 1872, and since then these elements were considered ectopic breast representing the caudal remnants of the milk ridges. It was only in 1991 and then in 1994 that van der Putte proposed that this tissue represents a normal constituent of the anogenital area which was supported by other authors. [9-11] Fibroadenoma of the vulva was reported as early as 1947 and a few times thereafter. [12-13]
The vulval fibroadenomas are diagnosed by fine needle aspiration cytology (FNAC) and/or histopathological examination of the tissue. Histopathological features are similar to those in breast. The differential diagnosis includes benign lesions like phyllodes tumor, hidradenoma papilliferum, lactating adenoma, fibrocystic disease, sclerosing adenosis, epidermal cyst, follicular cyst, Bartholin's gland duct cyst, intraductal papilloma, apocrine adenoma, syringoma, pseudoangiomatous stromal hyperplasia and malignant lesions like extramammary Paget's disease or ductal or mucinous carcinoma. [1-7] The lesion can be managed by simple excision and almost never recurs. The behavior of the tumor is benign as in the breast.
- Kazakov DV, Spagnolo DV, Stewart CJ, Thompson J, Agaimy A, Magro G, Bisceglia M, Vazmitel M, Kacerovska D, Kutzner H, Mukensnabl P, Michal M. Fibroadenoma and phyllodes tumors of anogenital mammary-like glands: a series of 13 neoplasms in 12 cases, including mammary-type juvenile fibroadenoma, fibroadenoma with lactation changes, and neurofibromatosis-associated pseudoangiomatous stromal hyperplasia with multinucleated giant cells. Am J Surg Pathol. 2010 Jan;34(1):95-103.
- Dhaoui A, Nfoussi H, Kchir N, Haouet S. Vulvar lactating adenoma associated to a fibroadenoma: common neoplasms in an uncommon site. Pan Afr Med J. 2012; 13:47. Epub 2012 Nov 13.
- Kalyani R, Srinivas MV, Veda P. Vulval fibroadenoma - a report of two cases with review of literature. Int J Biomed Sci. 2014 Jun;10(2):143-5.
- Ayadi-Kaddour A, Khadhar A, Mlika M, Braham E, Ismail O, Zegal D, El Mezni F. Fibroadenoma in an ectopic vulvar breast gland: a common neoplasm in an uncommon site. Pathologica. 2014 Mar;106(1):32-4.
- David Cantu de Leon, Delia Perez Montiel, Hugo Vazquez, Cesar Hernandez, et al. Vulval fibroadenoma: a common neoplasm in an uncommon site. World J. Surg. Oncol. 2009; 7: 70.
- Anunibi CC, Obiajulu FJN, Banjo AAF, Okonkwo AOE. Vulval fibroadenoma associated with lactating adenoma in a 26 year old Nigerian female. Case reports in Pathology. 2013; article ID 195703, 3 pages.
- Lin WC, Lin WL, Chuang YH, Shih PY, et al. An asymptomatic nodule in the vulva. Clinical and Experimental Dermatology. 2009; 33: 523-524.
- Lucas EW Jr, Branton P, Mecklenburg FE, Moawad GN. Ectopic breast fibroadenoma of the vulva. Obstet Gynecol. 2009 Aug;114(2 Pt 2):460-2.
- van der Putte SC. Anogenital ''sweat'' glands. Histology and pathology of a gland that may mimic mammary glands. Am J Dermatopathol. 1991; 13:557-567.
- van der Putte SC. Mammary-like glands of the vulva and their disorders. Int J Gynecol Pathol. 1994; 13:150-160.
- Kazakov DV, Spagnolo DV, Kacerovska D, Michal M. Lesions of anogenital mammary-like glands: an update. Adv Anat Pathol. 2011 Jan;18(1):1-28.
- Fisher JH. Fibroadenoma of supernumerary mammary gland tissue in vulva. Am. J. Obstet. Gynecol. 1947; 53; 335-337.
- Burger RA, Marcuse PM. Fibroadenoma of the vulva. Am. J. Clin.Pathol. 1954; 24; 965-968.
Contributed by Dinesh Pradhan, MD and Gloria Carter, MD