case_images: PMC2662405_01
case_images: Histological
  and immunohistochemical features of the scrotal serous cystadenoma at the side
  of an orchiopexy 14 years earlier. (a)
  Low magnification shows a tubulocystic tumor (between large arrowheads)
  surrounded by connective tissue and embedded in the dartos fascia (asterisks). 
  Note its connection to the epidermis by a sinus (1) lined by cornifying
  stratified squamous epithelium and opening at the surface (arrow). (b) Detail of metaplastic noncornifying
  stratified squamous epithelium (2) passing into a single-layered columnar
  epithelium of the tubulocystic system (3) in the deepest part of the sinus. (c) Cystic papillary component. (d) Detail of a fibrous papilla covered
  by characteristic tall columnar epithelium with ciliated cells (small
  arrowheads). (e) Cytological and immunohistochemical characteristics discriminating
  the tumor from other scrotal and intrascrotal lesions. Vim: Vimentin; ER: Estrogen receptor; PR: Progesterone receptor; Calret: Calretinin; SMA: Smooth muscle actin.
case_images: AU2009-610453.001.jpg
case_images: PMC2662405_01_AU2009-610453.001.jpg
case_images: fig1
case_images: Microscopic sections revealed an irregular tubulocystic epithelial proliferation surrounded by a mantle of connective tissue and embedded in the smooth musculature of the dartos fascia (Figure 1(a)). The tubulocystic element spread outward from a central sinus that opened externally at the surface of the skin and was lined by a cornifying stratified squamous epithelium (Figure 1(a)). Metaplastic noncornifying stratified squamous epithelium in the deepest part of the sinus passed into columnar to cuboidal epithelium in the tubulocystic component of the tumor (Figure 1(b)). In addition to the tubulocystic element, slit-like and papillary configurations were also observed (Figures 1(c), 1(d)). Variable numbers of cells showed prominent apical snouts or cilia (Figures 1(d), 1(e)).  The epithelium was bland, mitotic figures were rare, and microinvasion was absent.