Rapid progression of mucinous tubular and spindle cell carcinoma of the kidney without sarcomatoid changes: A case report

Early recurrence and extensive retroperitoneal metastasis after surgery for high‑grade mucinous tubular and spindle cell carcinoma: A case report and literature review

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare subtype of renal cancer. The present report details the treatment experience of a case of MTSCC, where the patient underwent a right-side laparoscopic nephrectomy in October 2020 at Zhuji People's Hospital (Zhuji, China). A total of 3 months post-operation, multiple metastases were discovered in the right renal area and retroperitoneum, with rapid disease progression observed in the subsequent 2 months. Treatment with tislelizumab combined with pazopanib was ineffective, and the patient subsequently died. Although MTSCC is generally considered a low-grade 'indolent' tumor, with most patients achieving long-term survival post-surgery, a minority of cases, especially those of a higher grade, may experience postoperative recurrence and metastasis. Due to the rarity of metastatic MTSCC, most studies are based on small sample sizes or case reports, and there is a lack of standardized systemic treatment and follow-up strategies for metastatic MTSCC. The present paper summarizes and analyzes the clinical features, treatment methods and prognosis of metastatic MTSCC cases reported in the literature, aiming to provide assistance for the treatment and follow-up management of metastatic MTSCC. Even in cases of distant metastasis, aggressive surgical treatment, metastasectomy combined with molecular targeted or immunotherapy, may still be recommended.

Mucinous tubular and spindle cell carcinoma of the kidney: a report of seven cases

OBJECTIVE

To further analyse the imaging features and tumour outcomes of mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney.

MATERIALS AND METHODS

The current study retrospectively reviewed the clinical information of seven patients diagnosed with MTSCC at our institution from January 2011 to March 2023.

RESULTS

The median age at diagnosis was 52 years (range, 32-66 years) and the majority of patients were female (71.4%). On conventional abdominal ultrasound, the majority of the tumours (5/7) were heterogeneous hypoechoic or slightly hypoechoic. Colour Doppler flow imaging showed blood flow within the tumour in 2 cases and peripheral blood flow signal in 1 case. On non-enhanced CT, all tumours had a spherical or ovoid shape, with an expansile growth mode, and had clear or unclear boundaries with the surrounding renal parenchyma. The tumours were either partially exophytic (n = 4) or parenchymal (n = 3), while no cases of completely exophytic tumour was observed (n = 0). On contrast-enhanced CT, the majority of tumours (5/7) showed a heterogenous pattern of enhancement and the mean tumour diameter was 6.7 ± 4.4 cm (range, 2.1-16.8 cm). All patients underwent partial or radical nephrectomy for pT1a (42.9%), pT1b (28.5%), pT2 (14.3%) or pT3b (14.3%) stage. Among these, 1 patient (14.3%) had a level I tumour thrombus at diagnosis and died of disease 24.5 months later. The remaining patients had no recurrence or metastasis.

CONCLUSION

MTSCC is not universally indolent, which tends to occur in female patients of a broad range of ages. MTSCC is a hypovascular renal tumour, which is different from clear cell renal cell carcinoma (RCC); however, it is difficult to distinguish MTSCC from other hypovascular RCC subtypes because of the overlap of their imaging characteristics.

Mucinous Tubular and Spindle Cell Carcinoma of the Kidney: A Study of Clinical, Imaging Features and Treatment Outcomes

Purpose

To describe the clinical, imaging, pathological features and oncologic outcomes of mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney.

Patients and Methods

Twenty-two cases of MTSCC were pathologically identified between January 2004 and April 2021 at our institution. The clinical and imaging findings, pathological features, treatment methods and outcomes of the patients were reviewed.

Results

These cases included 17 women and 5 men, with a median age at diagnosis of 52.5 years. On contrast-enhanced CT, MTSCC was less enhanced than the adjacent renal parenchyma. Tumor attenuation values were 33.3 ± 6.8HU, 44.0 ± 9.1HU, 54.4 ± 13.9HU and 67.1 ± 11.8HU in the non-contrast, corticomedullary, nephrographic and excretory phases of CT, respectively. Contrast-enhanced ultrasonography and MRI also showed hypovascular features of the masses. On MRI, the tumors were isointense on T1-weighted images and slightly hypo- or hyperintense on T2-weighted images. Diffusion-weighted imaging revealed a low apparent diffusion coefficient of the tumor. The patients were managed with laparoscopic partial nephrectomy (n=5), radical nephrectomy (n=16), or robotic-assisted laparoscopic partial nephrectomy (n=1). The median follow-up time was 59.5 months. All the patients were free of local recurrence or distant metastasis.

Conclusions

MTSCC is generally indolent and has favorable outcomes. The imaging features of MTSCC are generally hypovascular, which is significantly different from clear cell renal cell carcinoma. However, it is still difficult to distinguish MTSCC from other hypovascular renal tumors preoperatively because their imaging features overlap. Further studies are essential to fully characterize the features of this rare RCC variant.

Mucinous Tubular and Spindle Cell Carcinoma of the Kidney with Nodal Metastasis Managed with Surgical Resection

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare renal malignancy that usually follows an indolent course. The few existing reports of metastatic MTSCC show poor response to systemic therapy. Here we describe the unusual case of a 39-yr-old male with MTSCC presenting as a large renal mass with bulky retroperitoneal lymphadenopathy managed with complete resection of disease. He has remained free of recurrence for 1 yr postoperatively. On the basis of the experience reported here, aggressive surgical resection of MTSCC with isolated nodal metastases may be considered for similar patients in the future given the historically poor response rates to systemic therapy.