Mucinous Tubular and Spindle Cell Carcinoma- A Recently Added Entity Posing Diagnostic Challenges: Case Report with Review of Literature - Abstract
Background: Mucinous tubular and spindle cell carcinomas (MTSCC) are low grade renal epithelial neoplasms, recently described as a subtype of renal cell carcinoma.
Aim: To report the histopathological and immunohistochemical features of MTSCC to solve the diagnostic challenges associated with the diagnosis of this tumour. Also adding a new case for better understanding of this rare entity with limited literature available.
Materials and methods: A single case of renal MTSCC was studied along with review of literature. HPE and IHC were done for confirmation of diagnosis.
Results: A 40 years old female presented with chief complain of left flank pain since last one year. Radiological findings revealed a mass lesion involving the mid pole of the left kidney. Left nephrectomy was done laproscopically and submitted for HPE. Grossly, cut surface of the kidney showed a single well
circumscribed, grayish white to yellowish white, firm growth measuring 4.5 x 3 x 1.5 cm in size, present in the midrenal area. HPE showed tumor cells arranged in tubules and cords separated by pale mucinous stroma with minimal nuclear atypia and low mitotic index. At places, the tumour cells were seen transitioning into anastomosing spindle cells. Clear cell changes and occasional psammoma bodies were also noted. IHC stains were strongly positive for CK 7, AMACR and EMA, weakly positive for CK 19 while negative for CD10 and RCC with a low Ki 67 index.
Conclusions: In spite of diagnostic challenges, on the basis of histomorphological and immunohistochemical featuresa final diagnosis of MTSCC was made. MTSCC shares some overlapping histomorphological features with RCC with sarcomatoid features, papillary RCC, clear cell RCC and collecting duct carcinoma. Immunohistochemistry as well as a thorough morphological assessment is necessary to avoid a misdiagnosis.