A rare case of primary clear-cell adenocarcinoma of the bladder arising from bladder endometriosis

Clear Cell Adenocarcinoma in Men: A Series of 15 Cases

Clear cell adenocarcinoma (CCA) is a rare tumor in the genitourinary tract with female predominance and few reports in men. We identified 15 cases of CCA in men evaluated at our institution. Five arose in the bladder, 7 in the prostate or prostatic urethra, 2 in the membranous urethra (1 multifocal in the prostatic and membranous urethra), 1 periprostatic (likely from an embryologic remnant), and 1 between rectum and bladder (likely in a prostatic utricle cyst). No cases showed associated Müllerian structures. One case showed separate foci of nephrogenic adenoma at diagnosis, and 1 case showed urothelial carcinoma in situ on a later follow-up biopsy. Four tumors extended into other organs (prostate to seminal vesicle and periprostatic soft tissue, periprostatic soft tissue to prostate, prostatic urethra to bladder and rectum, and prostate to bladder neck). One tumor showed extraprostatic extension alone. Four tumors metastasized to lymph nodes, with 3 also metastasizing to other sites (bladder, lung and adrenal, and right flank). Eleven patients underwent resection, including 3 transurethral resections. Seven underwent other treatments, including radiation (5 [1 for recurrence]), chemotherapy (3), hormonal therapy (3), immunotherapy with nivolumab (1), and targeted therapy with gefitinib (1). The mean follow-up was 35 months (range: 1 to 138 mo). At the last follow-up, 7 patients showed no evident disease and 3 were alive with disease. Four died with the cause of death unknown, with 2 cases having confirmed disease at the time of death and the remaining 2 dying less than a year after diagnosis. The mean time to death was 16 months (range: 6 to 39 mo). No follow-up was available on 1 patient. All patients who died in this series had CCA of the prostate or prostatic urethra. Pathologists need to be attuned to CCA occurring in males, given that the literature emphasizes its occurrence in females. In addition to established sites such as bladder and urethra, our series demonstrates that tumor may present in unusual adjacent sites, such as in periprostatic embryologic remnants or prostatic utricle.

Molecular profiling of clear cell adenocarcinoma of the urinary tract

Clear cell adenocarcinoma (CCA) of the urinary tract is a rare type of malignancy whose molecular profiles remain undefined. Here we reported an integrated clinicopathologic and molecular profiling analysis of four cases of clear cell adenocarcinoma arising in the urethra or the bladder. Utilizing a clinically validated 130-gene exon-sequencing assay, we identified recurrent pathogenic PIK3CA (p. E545K) and KRAS (p.G12D) variants in three of four (75%) of the cases. In addition, an APC variant (P.S2310X), a TP53 variant (p.R273C), and a MYC amplification event were identified. The only CCA case without either PIK3CA or KRAS variants has a distinct pathogenesis through BK virus, demonstrated by positive BK virus PCR and SV40 immunohistochemistry. The novel finding of recurrent variants in the PI3K/AKT/mTOR pathway provides not only insights into oncogenesis but also potential clinical therapeutic targets for patients with clear cell adenocarcinoma of the urinary tract.

Vesical clear cell adenocarcinoma arising from endometriosis: A mullerian tumor, indistinguishable from ovarian clear cell adenocarcinoma

Endometriosis is associated with increased rates of ovarian, particularly clear cell, adenocarcinomas. Malignant transformation of ovarian endometriosis is most common but rare cases have been reported in the bladder, abdominal wall, diaphragm, and rectum. We present the case of a 44-year-old female with vesical clear cell adenocarcinoma arising in a background of endometriosis in the absence of other pelvic endometriosis. The malignancy was diagnosed on transurethral resection of bladder tumor and managed with radical surgery. Histology and immunohistochemical findings were consistent mullerian origin and indistinguishable from similar tumors arising in the female genital tract. Extrapolating from the gynecologic literature, the recommendation was made for adjuvant chemotherapy. Further studies are needed to clarify the optimal treatment paradigm for ovarian and bladder clear cell adenocarcinomas.

•

Malignant transformation of extra-ovarian endometriosis is rare

•

Histology and immunohistochemistry support mullerian origin of this malignancy

•

Consideration can be given to extrapolating treatment from gynecologic literature