A synchronous occurrence of urothelial carcinoma with abundant myxoid stroma and inverted papilloma of the urinary bladder

Urothelial carcinoma of the bladder with abundant myxoid stroma: A case report and literature review

INTRODUCTION

Abundant myxoid stroma rarely occurs in urothelial carcinomas (UCs). We report an 83-year-old woman with UC of the urinary bladder with abundant myxoid stroma. We summarized the clinicopathological features, immunophenotype, diagnosis, and differential diagnosis of this type of bladder cancer, in order to improve the understanding of surgeons and pathologists.

PATIENT CONCERNS

An 83-year-old female presented with hematuria and frequent micturition, without odynuria, hypogastralgia, or fever.

DIAGNOSIS

The computed tomography scan demonstrated extensive tumors in the anterior wall of the bladder and a soft tissue shadow anterior to the sacrum. Cystoscopy showed massive wide-based tumors located on the anterior and lateral walls of the bladder, with no tumor involving the bladder neck. Multiple punch biopsies were performed, the histologic evaluation of which revealed a poorly differentiated invasive UCs with myxoid stroma.

INTERVENTIONS

The patient underwent a laparoscopic radical cystectomy and cutaneous ureterostomy.

OUTCOMES

The patient discharged without any complications. Histologic evaluation revealed an invasive UC; the most prominent feature was an abundant myxoid stroma that covered approximately 80% of the lesion and the tumor cells were arranged in cords, small nests, or a sheet-like structure. Immunohistochemically, the tumor cells were positive for CK19, CK20, VEGF, EGFR, p63, 34βE12, MUC1, GATA3, uroplakin3, and TopII (rate = 15%), while the Ki-67 proliferation index was 10%. The myxoid stroma in the mesenchyme stained positively with AB-PAS and colloidal iron, and some tumor cells stained positive for colloidal iron. Considering the histologic, histochemical, and immunohistochemical findings, a diagnosis of UC with abundant myxoid stroma was made. After surgery, the regular follow-up was continued in clinic, and there was no recurrence for 2 years.

CONCLUSION

Morbidity associated with UC with abundant myxoid stroma is very low. The diagnosis mainly depends on histopathological and immunohistochemical findings.

Invasive urothelial carcinoma with chordoid features of the ureter: a rare entity and review of literature

Invasive urothelial carcinoma (UC) is characterized by some histologic variants that can sometimes lead to diagnostic difficulty. In addition to those described by the World Health Organization. Recently invasive urothelial carcinoma with chordoid features (UCC) has been described as a distinct entity and there are relatively few reported cases in the English-language literature. To date 13 cases of UCC have been reported in 2 case series, respectively in 2009 and 2015. We report the 14(th) case in an 80-year-old female, and to the best of our knowledge this is the second case report of UCC in the ureter. She was admitted to our hospital with macroscopic haematuria and unspecific left lower abdominal pain. Computed tomography scan revealed a soft tissue nodule in the middle of the left ureter. The left nephroureterectomy was performed. Morphologically, 85% areas had acellular myxoid stroma was associated with the neoplastic cells. The neoplastic cells had scant eosinophilic cytoplasm and were arranged into cords closely mimicking chordoma or extraskeletal myxoid chondrosarcoma. 15% areas was typical invasive urothelial carcinoma, and focal areas had transition phenomenon between them. Immunohistochemically, the tumor cells were positive for CK, 34βE12 and p63, but were negative for S100, AFP, CD34, Syn and CgA. The final histopathological diagnosis was UCC of the ureter.

Mucinous urothelial carcinoma of the renal pelvis

Urothelial carcinoma with abundant myxoid stroma is a newly-described and extremely rare entity. Since only very few cases have been reported, there is no consensus on its nomenclature. Microscopic examination revealed invasive urothelial carcinoma with widespread low-grade noninvasive areas. There were focal invasive areas in the neighborhood of the renal parenchyma. Malignant urothelial tumor/cell groups localized in the stroma had abundant myxoid/mucinous background in the invasive areas. The cytoplasm of the tumoral cells was more eosinophilic in these areas and the cells formed small groups and cords. Histochemically, PAS and Alcian Blue were positive in the cytoplasm of the tumoral cells and in the stroma while negative in the non-mucinous areas. Immunohistochemically, the tumoral cells of the mucinous invasive areas diffusely expressed MUC1 and MUC2. We discuss the origin of the mucinous/myxoid stroma, the tumor’s nature and its nomenclature with histochemical and immunohistochemical features.