2020-41 / October 12
Contributors: Constantina Petraki

Nephrectomy for a renal mass in female patient in her 50s. H&E and CD10 immunostains are shown.


1. What is the correct diagnosis?

a. Unclassified renal cell carcinoma

b. Papillary renal cell carcinoma, solid type

c. Mucinous tubular and spindle cell carcinoma of the kidney

d. Angiomyolipoma

e. Papillary renal cell carcinoma with sarcomatoid transformation

1. Mucinous tubular and spindle cell carcinoma of the kidney

Nephrectomy was performed on a female patient in her 50s for an incidentally identified 5.1 cm renal mass. The tumour was circumscribed, tan-brown/yellow. Microscopic examination revealed a pT1b biphasic tumour with tubular and spindle cell morphology and focally various mucinous stroma and foamy cells. The tumour cells were positive for PAX8, PAX2, AMACR and CK8-18. CK7, KSP-Cadherin, CA IX, CD15 and Vimentin were focally positive. CD10 was mainly negative (shown). CD117, ALK1, CKHMW, CK20 and Cathepsin K were negative. SDHB and Fumarate Hydratase were retained. The Ki-67/MIB1 index was low (≤5%).

Mucinous tubular and spindle cell carcinoma is a rare renal epithelial neoplasm characterized by tubular formations merging with bland spindle cells and a variably myxoid stroma. The nuclei have low grade features. Immunohistochemically, the tumour cells are generally positive for CK7, PAX8, PAX2 and AMACR and mostly negative for CD10. Most tumours have an indolent behaviour and recurrence is rare. Tumours with high grade transformation and metastases have been reported. The differential diagnosis includes mainly the papillary renal cell carcinoma with solid growth pattern and the papillary renal cell carcinoma with sarcomatoid transformation. The later has high nuclear atypia in the stroma and is generally CD10 positive.

Ged Y, Chen YB, Knezevic A, Donoggue MTA, Carlo M, Lee CH, Feldman DR, Patil S, Hakimi AA, Russo P, Vosa MH, Motzer RJ. Mucinous tubular and spindle-cell carcinoma of the kidney: Clinical features, genomic profiles, and treatment outcomes. Clin Genitourin Cancer 2019 ,17 (4): 268–274.

Adamane SA, Menon S, Prakash G, Bakshi G, Joshi A, Popat P, Desai SB. Mucinous tubular and spindle cell carcinoma of the kidney: Acase series with a brief review of the literature. Indian J Cancer 2020, 57 (3): 267-281.

Constantina Petraki, MD PhD
Metropolitan Hospital, Athens, Greece


Kidney, mucinous tubular and spindle cell carcinoma, renal cell carcinoma subtypes