Primary signet ring cell adenocarcinoma arising in exstrophy of the urinary bladder (epispadias-exstrophy complex)

Bladder exstrophy is a rare congenital anomaly in which the urinary bladder develops outside the body. It may be part of the bladder epispadias-exstrophy-cloacal complex, which is a serious embryological defect where a spectrum of abnormalities involving the urinary tract, genital tract, musculoskeletal system, and intestinal tract is seen. Primary signet ring cell adenocarcinoma (PSRCA) arising in exstrophy of the urinary bladder is extremely rare with only a few cases reported in the literature. A 32-year-old man with congenital, untreated bladder exstrophy presented with a large fungating mass on the lower abdominal wall. Physical examination revealed a 15 × 12 cm exophytic mass with a penile epispadias. Ultrasonography showed a replacement of the urinary bladder by a mass of size 9 × 8 × 7 cm with a defect in the abdominal wall. On Contrast-enhanced computed tomography (CECT), a mass protruding from a large, inferior abdominal wall defect of 5.3 cm was seen. Widened pubic symphysis with divarication of recti and an absent urinary bladder, consistent with bladder exstrophy, was also noted. The biopsy showed a signet ring cell adenocarcinoma. A radical cystectomy with ileal conduit and left inguinal lymph node dissection was done. Histopathology examination revealed a PSRCA with metastasis to the left inguinal lymph nodes. Immunohistochemistry (IHC) showed strong positivity with CDX2 and CK20 while CK7 was negative. PSRCA shows an aggressive behavior, as was seen in our case, which had metastatic inguinal lymph nodes at the time of presentation. Metastatic signet ring cell adenocarcinomas from other sites need to be ruled out. Bladder exstrophy can develop high-grade malignancies at any stage of life. Hence, surgical treatment early in life with lifelong follow-up is recommended.