Anatomical Pathology Interesting Case Conference

Microscopic Description:

Histology reveals spindle cells arranged in sheets with hyperchromatic pleomorphic nuclei, mitotic figures are seen surrounded by myxoid stroma.

Tumor cells are invading the Muscularis propria.

Immunohistochemistry was positive for AE1/AE3, Desmin, Pancytokeratin is focally positive.

Discussion:

Sarcomatoid urothelial carcinoma is an aggressive biphasic tumor exhibiting morphological and immunohistochemistry of both epithelial(urothelial) and mesenchymal(spindle-shaped) origin. It accounts for 0.3 % of all urothelial cancers.

Occurs in (51-88 years) in both men and women, with more prevalence in men.

Urothelial Carcinoma can occur in upper tract (ureter to pelvis, 5-10%) or lower tract (bladder and urethra, 90-95%).

Etiology: smoking, chemical exposures(aromatic amines, hydrocarbons, dyes), genetic changes causes urothelial carcinoma but the expression of (epithelial-to-mesenchymal transition) EMT-related biomarkers in sarcomatoid carcinoma of the bladder, in particular vimentin, FocC2, SNAIL, and ZEB1 have been reported.

Clinical features: increased frequency, dysuria, gross hematuria, flank pain, hydronephrosis.

Grossly, it can be polypoid, pedunculated, broadly based, projecting into the bladder lumen and has gray fleshy cut surface.

Microscopy, atypical urothelial cells with mitosis, necrosis, spindled shape tumor cells with pleomorphic nuclei in the background of myxoid or sclerosing stroma. The tumors cells can be seen invading the muscle layer. Occasional mitotic figures can be seen.

Immunohistochemistry is positive for AE1/AE3, GATA3, CK7, p53, Vimentin, EMA, SMA, high Ki-67 proliferation index.

Treatment includes neoadjuvant chemotherapy followed by radical cystectomy( bladder preservation surgery has worst outcome), and the use of immune checkpoint inhibitors (PD-1/PD-L1) in metastasis cancer, which improve clinical management and offer survival benefits.

There is a high risk of recurrence, metastasis and a poor prognosis as it frequently presents at a later stage. The prognosis is determined by the involvement of detrusor muscle, presence of myxoid or chordoid features.. Due to its aggressive nature, approx. 50 % patients die within one year of presentation.

References:

Fatima N, Canter DJ, Carthon BC, Kucuk O, Master VA, Nieh PT, Ogan K, Osunkoya AO. Sarcomatoid urothelial carcinoma of the bladder: a contemporary clinicopathologic analysis of 37 cases. Can J Urol. 2015 Jun;22(3):7783-7.

Sanfrancesco J, McKenney JK, Leivo MZ, Gupta S, Elson P, Hansel DE. Sarcomatoid Urothelial Carcinoma of the Bladder: Analysis of 28 Cases With Emphasis on Clinicopathologic Features and Markers of Epithelial-to-Mesenchymal Transition. Arch Pathol Lab Med. 2016 Jun;140(6):543-51.

Lopez-Beltran A, Cimadamore A, Blanca A, Montironi R, Cheng L. Sarcomatoid urothelial carcinoma: advances and challenges. Curr Opin Urol. 2026 Mar 1;36(2):147-154.

Rouanne M, Bajorin DF, Hannan R, Galsky MD, Williams SB, Necchi A, Sharma P, Powles T. Rationale and Outcomes for Neoadjuvant Immunotherapy in Urothelial Carcinoma of the Bladder. Eur Urol Oncol. 2020 Dec;3(6):728-738. doi: 10.1016/j.euo.2020.06.009.

 

Bansal A, Kumar N, Sharma SC. Sarcomatoid variant of urothelial carcinoma of the urinary bladder. J Cancer Res Ther 2013; 9(4): 571-3.

UroToday. (2026). Urotoday.Com. https://www.urotoday.com/uij-archives/95096-contemporary-treatment-patterns-and-outcomes-of-sarcomatoid-bladder-cancer-beyond-the-abstract.html

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