A 37-year-old woman presented with complaint of an episode of macroscopic, painless hematuria. She had a similar episode 3-months previously and was seen at another hospital and told to have a small bladder lesion detected by ultrasonography. There was no history of catamenial exacerbation or association for either episode. She defaulted follow-up till this current episode. Apart from laparoscopic removal of an ovarian cyst (5 × 4 × 2 cm) six years ago at a different hospital, the patient was otherwise well. Review of the hematoxylin and eosin stained sections confirmed that the ovarian cyst was a benign mucinous cystadenoma lined by single-layered endocervical-like epithelium. The patient also gave a history of two caesarean sections, thirteen and eleven years earlier. Physical examination revealed no significant findings. The patient underwent cystoscopic examination and transurethral resection of the lesion at the posterior dome of the bladder under spinal anesthesia.
Multiple rubbery, whitish-grey tissue fragments of varying sizes and shapes, measuring 1.5 × 1.2 × 0.5 cm in aggregate were resected. The fragments of bladder tissue revealed glands lined by a single-layered mucinous columnar epithelium with basal nuclei reminiscent of endocervical epithelium in the lamina propia and extending into the muscularis propia. These endocervicosis glands ranged from round to branched (Figure ). Occasional glands were cystically dilated and contained mucin. The overlying urothelium was intact and generally unexceptional except for alteration to single-layered mucinous columnar epithelium that resembled endocervical epithelium in a few areas. Mitotic activity was not detected in any of the tissue components. The lamina propia was mildly edematous with focal congestion of the vasculature and infiltrate of lymphocytes, plasma cells, neutrophils and eosinophils. Rare hemosiderin-laden macrophages were testimony to hemorrhagic episodes.
Figure 1 Histologic findings of the transurethral resected bladder tissue. (A) Endocervicosis showing round to branched endocervical-like glands with surrounding smooth muscle in the bladder (H + E × 40). (B) Surface mucinous epithelium delineated from (more ...)
4-μm sections of the formalin-fixed, paraffin-embedded tissue were subjected to immunohistochemical staining using monoclonal antibodies to pancytokeratin AE1/AE3 (DakoCytomation AE1/AE3, 1:100), CK7 (DakoCytomation OV-TL 12/30, 1:100), CK19 (DakoCytomation RCK108, 1:100), CK5/6 (DakoCytomation D5/16 B4, 1:100), CK20 (DakoCytomation Ks20.8, 1:100), HBME-1 (DakoCytomation HBME-1, 1:100), estrogen receptor (ER) (NeoMarkers SP1, 1:100) and progesterone receptor (PR) (DakoCytomation PgR 636, 1:200) via the EnVision™+ (DakoCytomation) system.
Southgate's mucicarmine clearly delineated the mucinous epithelium from the adjacent urothelium in this case (Figure ). Table summarises the immunohistochemical expression profile of the urothelium, surface mucinous epithelium and endocervicosis glands. As expected, AE1/AE3, CK7 and CK19 were ubiquitously expressed by all epithelial components. CK 5/6 was noted in the basal cells of the urothelium while the surface mucinous and endocervicosis epithelia were immunonegative (Figure ). Faint CK20 expression was only noted in few umbrella cells of the urothelium. HBME-1 was expressed on the apical margin of endocervicosis glands. In contrast, the surface mucinous epithelium and urothelium were immunonegative. The endocervicosis glandular and surface mucinous epithelial cells demonstrated nuclear ER (Figure ). Endocervicosis glandular cells generally demonstrated nuclear PR with rare cells exhibiting mixed cytoplasmic and nuclear positivity. Contrastingly, PR was expressed in both the nuclei and cytoplasm of the surface mucinous epithelial cells while no PR was seen in the urothelium.
Antibody expressions in urothelium, surface mucinous epithelium and endocervicosis glands