Yolk sac tumor differentiation in urothelial carcinoma of the urinary bladder: a case report and differential diagnosis

Abstract

Background: Yolk sac tumor (YST) is a germ cell neoplasm that arises predominantly in the gonads, but can also derive from somatic neoplasms in extragonadal locations. These latter cases have been documented in several organs, although reports from the urinary tract are limited. To our knowledge, this is the first report of a bladder urothelial carcinoma with a predominant component of YST differentiation. Case presentation: We present a unique case of a 76-year-old man with a recurrent urinary bladder tumor, initially interpreted as a high grade urothelial carcinoma with glandular differentiation. In the recurrent tumor, diverse histological patterns were identified, including glandular, hepatoid and sarcomatoid. This tumor showed positivity for AFP, GLP3 and SALL4, and negativity for CK7 and EMA. Fluorescent in situ hybridization study showed a polysomic pattern of chromosome 12. All these findings led to the final diagnosis of a YST derived from urothelial carcinoma. Conclusions: YST differentiation should be considered in the differential diagnosis of a high grade urothelial carcinoma, particularly when glandular and other unusual patterns are observed.

Primary adenocarcinoma with yolk sac differentiation in the transplant ureter and salvage of the transplant kidney: a rare case report

“…YSD has not yet been recognized as a separate subtype of UC by the World Health Organization; however, an extensive literature search revealed a few case reports [ 8 , 9 ]. YSD has been reported in several other somatic malignancies, including those at gastrointestinal [ 10 , 11 ] and gynecological sites [ 12 , 13 ].…”

Urachal yolk sac tumor penetrating the bladder as a diagnostic challenge: a case report and review of the literature

“…YST differentiation of somatic tumors is relatively rare, and reported cases of YST differentiation of urothelial tumors are even less common [ 6 , 16 , 17 ]. Histologically, tumors can contain both YST and somatic tumor structures.…”

“…There are also documented cases of bladder adenocarcinomas that have shown both immunoreactivity for AFP and elevated serum AFP levels [ 16 ]. Recently, a case of urothelial tumor with YST differentiation was presented by Espejo-Herrera et al The patient was a 76-year-old male with a history of recurrent urothelial carcinoma of the bladder [ 17 ].…”

Unusual Faces of Bladder Cancer

“…A very limited number of UC with yolk sac tumor differentiation has been reported in the literature [ 52 , 53 , 54 , 55 ]. The yolk sac differentiation represents an example of a somatic differentiation present in non-gonadal neoplasms [ 56 ].…”

“…Markers of intestinal differentiation, like CDX2, are usually positive in enteroblastic areas and Her Par-1 in hepatoid ones. A polysomic abnormality in 12p has been detected in one recently published case [ 55 ].…”