Bilateral renal mucinous tubular and spindle cell carcinoma (MTSCC) – an extremely rare occurrence in children

Abstract

Introduction Mucinous tubular and spindle cell carcinoma of kidney (MTSCC) is extremely rare in children. Management of these tumours involve complex issues. Herein, we present a rare case with bilateral renal involvement who later developed progressive disease (bilateral lung, liver and bony metastases). Methods A thirteen-year-old boy presented to our Oncology Clinic with episodes of haematuria and bilateral dull-aching flank pain for last 9 months. On examination, there was presence of a large, 10x10 cm sized, firm mass occupying the right lumbar and right hypochondrium regions with extension beyond the midline. Contrast enhanced computed tomogram of the abdomen confirmed the presence of a large heterogeneous mass arising from right kidney with areas of calcification and displacement of inferior vena cava (IVC) to the left. Similar but smaller masses were seen involving the left kidney. Core biopsy of the right sided tumour was consistent with features of MTSCC. Intraoperatively, multiple dilated tortuous vessels overlying the mass resulted in abandoning the surgery. Tumour biopsy confirmed the presence of MTSCC of the kidney. Post-operatively, child was started on metronomic therapy but showed poor response and developed progressive disease with bilateral lung, liver and bony metastases. Results Child developed progressive disease and died while on metronomic therapy. Conclusions MTSCC of kidney is a rare tumour that can pose both a diagnostic and therapeutic challenge. Metastases, even in cases with low-grade morphology, have been reported. While surgical resection (partial or radical nephrectomy) is usually preferred modality for localized disease, no systemic treatment guidelines are established for metastatic disease. Few cases of metastatic MTSCC have shown response to Sunitinib.