Search

Abstract 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.

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. [ABSTRACT FROM AUTHOR]

Background/Aim: Mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney is a rare histological type of renal cell carcinoma (RCC). There are few reports of MTSCC occurring in renal transplant recipients (RTRs). The aim of this study was to report a case of long-term survival of a RTR with metastatic MTSCC of the kidney with sarcomatoid changes. Case Report: A 53-year-old male with a left retroperitoneal tumor was referred to our department. He had been receiving hemodialysis since 1991 and underwent kidney transplantation in 2015. Computed tomography (CT) revealed suspected RCC, and a radical nephrectomy was performed in June 2020. Pathological findings revealed MTSCC with sarcomatoid changes. After the surgery, multiple metastases appeared in the bilateral adrenals, skin, para-aortic lymph nodes, muscles, mesocolon, and liver. We treated the patient with metastasectomy, radiation therapy, and sequential systemic therapy with tyrosine kinase inhibitors (TKI). Two years after the initial surgery, the patient died of cancer while controlling its progression. Conclusion: We report a RTR with aggressive and metastatic MTSCC with sarcomatoid changes, resulting in a longer survival time relative to multimodal therapy. [ABSTRACT FROM AUTHOR]

Abstract Background Anaplastic lymphoma kinase rearrangement-associated renal cell carcinoma (ALK-RCC) is an extremely rare tumor and ALK-RCC that mimics mucinous tubular and spindle cell carcinoma (MTSCC) has been very reported only in one instance. Case presentation A 42-year-old Japanese woman was admitted to our hospital for the treatment of a left renal tumor measuring 5 cm in maximum dimension. She underwent a laparoscopic left nephrectomy. Histologically, the tumor formed tubular or focally papillary structures with a small amount of spindle-shaped tumor cells against the background of prominent extracellular mucin. Although the tumor cells were negative for immunohistochemistry (IHC) of alpha-methylacyl-CoA racemase (AMACR) and lymph node metastasis was presented (these are atypical findings for MTSCC), we initially diagnosed the tumor as MTSCC based on its morphological characteristics with mucin deposition. However, an additional IHC analysis revealed that the tumor cells were diffusely positive for ALK-IHC. In addition, TPM3 exon 8 – ALK exon 20 fusion gene was detected by RNA sequencing. The tumor was thus correctly diagnosed as ALK rearrangement-associated renal cell carcinoma (ALK-RCC). Conclusions Since the use of molecular targeted therapy with an ALK inhibitor for ALK-RCC is promising, the correct pathological diagnosis of ALK-RCC is quite important. We strongly recommend that ALK-IHC be routinely performed for renal tumors with negative AMACR staining that mimic MTSCC.

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. [ABSTRACT FROM AUTHOR]

Mucinous Tubular and Spindle Cell Carcinoma (MTSCC) of the kidney is a rare variant, first classified by WHO in 2004 classification of RCC. MSCC has distinct morphology and immunohistochemistry unlike challenging previous renal tumor classifications. Despite its rarity, MTSCC diagnosis is important due to its unique characteristics. We present a 56-year-old female with a decade-long history of right-side abdominal pain and swelling. Physical examination revealed a 15*10 cm mass on the right flank. Imaging indicated a heterogeneously enhancing right renal mass, diagnosed as localized right Renal Cell Carcinoma (RCC). A radical nephrectomy was performed, and the biopsy confirmed MTSCC. The patient was discharged on the 6th post-op day, with no adjuvant treatment due to localized tumors. MTSCC, constituting <1 % of RCC, primarily affects females (1:3–4) with an indolent course. Radical nephrectomy is the preferred treatment, offering a favorable prognosis. However, a small percentage may experience metastasis, necessitating mandatory follow-up. MTSCC of the kidney is a rare RCC variant with an excellent prognosis. Surgical excision, specifically radical nephrectomy, is the mainstay of treatment. Adjuvant therapy may not be required for localized tumors. Postoperative follow-up is crucial, despite the rare risk of metastasis reported in some cases. • Mucinous tubular and spindle cell carcinoma of the kidney is a rare variant of renal cell carcinoma. • Mucinous tubular and spindle cell renal cell carcinoma is a low-grade carcinoma with an indolent natural course. • The main mode of management for any type of renal cell carcinoma is surgical excision. • The majority of diagnoses of mucinous tubular and spindle cell carcinoma of the kidney are done by pathology mainly morphology but if there is any difficulty in diagnosing via morphology we can do immunohistochemical staining and FISH technique. • The prognosis is excellent with long-term survival and a low risk of recurrence and metastasis. [ABSTRACT FROM AUTHOR]

Purpose: To strengthen the recognition of mucinous tubular and spindle cell carcinomas of the kidney (MTSCC-Ks) by analyzing CT and MR imaging findings of MTSCC-Ks. Materials and methods: This study retrospectively enrolled ten patients with pathologically confirmed MTSCC-Ks from 2007 to 2020. The main observed imaging characteristics included growth pattern, signal characteristics on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI), hemorrhage, necrosis, cystic degeneration, lipid component, pseudocapsule and the enhancement pattern. Apparent diffusion coefficient (ADC) value of MTSCC-Ks and normal renal cortex were measured, respectively. All imaging features were evaluated in consensus by two genitourinary radiologists. Results: All patients (53.1 ± 6.5 years, male to female, 3:7) presented with a solitary renal tumor with the mean diameter of 3.5 ± 0.4 cm. All lesions showed iso- or slight hypoattenuation on non-contrast CT with no hemorrhage but cystic degeneration (10%) and necrosis (10%). On T2WI, all lesions showed predominantly slight hypointensity with focal hyperintensity. The ADC value of MTSCC-Ks was 0.845 ± 0.017 × 10−3 mm2/s, and ADCtumor-to-ADCrenal cortex value was 0.376 ± 0.084. Pseudocapsules existed in all MTSCC-Ks on MRI. There were seven lesions showed heterogeneous enhancement, while three lesions showed homogeneous enhancement. Among them, six MTSCC-Ks showed slight multiple patchy enhancement (60%) in the corticomedullary phase, while the remaining MTSCC-Ks showed homogeneously slight enhancement (30%) or slightly stratified enhancement (10%). All MTSCC-Ks exhibited slow and progressive enhancement in the late phases. Conclusion: Iso- or slight hypoattenuation on CT, slight hypointensity with focal hyperintensity on T2WI, marked diffusion restriction on DWI and ADC map, slight multiple patchy enhancement in the corticomedullary phase, and slow and progressive enhancement in the late phases are the imaging features of MTSCC-Ks, which may facilitate the diagnosis of MTSCC-Ks. [ABSTRACT FROM AUTHOR]

Mucinous tubular and spindle cell renal cell carcinoma (MTSC-RCC) is a rare but favorable variant of renal cell carcinoma, predominantly found in adults. Complete surgical excision is the treatment of choice. We are reporting an intriguing case of bilateral MTSC-RCC in a 13-yearold-boy with rapid disease progression, leading to metastatic disease and subsequent demise of the child. [ABSTRACT FROM AUTHOR]

Mucinous tubular and spindle cell carcinoma (MTSCC) of kidney is a rare variant of renal cell carcinoma which was first described in the 2004 World Health Organization classification of tumours of the kidney. Morphologically, MTSCC is composed of tubules merging with bland appearing spindle cells in a myxoid/mucinous stroma. Diverse morphological patterns have been reported in MTSCC; however, a spindle cell predominant morphology mimicking a mesenchymal tumour is rare and only two cases have been reported so far. We report a case of MTSCC with spindle cell predominance in kidney which was a diagnostic challenge. Though MTSCC usually shows an indolent course, there have been cases showing aggressive behaviour even with bland morphology. Hence, a thorough histopathological evaluation with ancillary studies are required to differentiate spindle cell predominant MTSCC from its mimics. Our case was a 40-year-old female who was incidentally found to have a well-defined hypodense lesion measuring around 2 cm in the upper pole of the right kidney. Right partial nephrectomy was performed which showed a 2.7 × 2.5 × 2 cm well-defined grey tan tumour without necrosis or haemorrhage, limited to kidney. Histopathological examination showed sheets of bland-appearing spindle cells mimicking a mesenchymal tumour. The tumour was extensively sampled, revealing small foci of tubule formation and mucinous stroma. Tumour cells were positive for CK7, AMACR, and PAX8. A final diagnosis of MTSCC was made. Hereby, we discuss ways of differentiating MTSCC from other spindle cell tumours of the kidney. [ABSTRACT FROM AUTHOR]

Introduction Mucinous tubular and spindle cell carcinoma is a rare subtype of renal cell carcinoma. Little is known regarding the efficacy of systemic therapy on its metastatic form because of its rarity. Case presentation We present the case of a patient with metastatic mucinous tubular and spindle cell carcinoma who achieved durable complete remission of multiple osseous metastases after undergoing cytoreductive nephrectomy followed by combination immunotherapy (ipilimumab plus nivolumab). Immunohistochemical analyses of the primary tumor revealed the presence of the tumor‐infiltrating immune cells, including activated CD8+ T cells and PD‐L1 expression, suggesting an immunologically hot tumor. Conclusion Combination immunotherapy was a viable treatment option for this disease. Immunohistochemical analyses of the tumor‐infiltrating immune cells predicted the efficacy of immune checkpoint inhibitors against rare renal cancers.

Background: Anaplastic lymphoma kinase rearrangement-associated renal cell carcinoma (ALK-RCC) is an extremely rare tumor and ALK-RCC that mimics mucinous tubular and spindle cell carcinoma (MTSCC) has been very reported only in one instance. Case presentation: A 42-year-old Japanese woman was admitted to our hospital for the treatment of a left renal tumor measuring 5 cm in maximum dimension. She underwent a laparoscopic left nephrectomy. Histologically, the tumor formed tubular or focally papillary structures with a small amount of spindle-shaped tumor cells against the background of prominent extracellular mucin. Although the tumor cells were negative for immunohistochemistry (IHC) of alpha-methylacyl-CoA racemase (AMACR) and lymph node metastasis was presented (these are atypical findings for MTSCC), we initially diagnosed the tumor as MTSCC based on its morphological characteristics with mucin deposition. However, an additional IHC analysis revealed that the tumor cells were diffusely positive for ALK-IHC. In addition, TPM3 exon 8 – ALK exon 20 fusion gene was detected by RNA sequencing. The tumor was thus correctly diagnosed as ALK rearrangement-associated renal cell carcinoma (ALK-RCC). Conclusions: Since the use of molecular targeted therapy with an ALK inhibitor for ALK-RCC is promising, the correct pathological diagnosis of ALK-RCC is quite important. We strongly recommend that ALK-IHC be routinely performed for renal tumors with negative AMACR staining that mimic MTSCC. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

PurposeTo describe the clinical, imaging, pathological features and oncologic outcomes of mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney.Patients and MethodsTwenty-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.ResultsThese 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.ConclusionsMTSCC 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.

Background/Aim: Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare subtype of renal cell carcinoma and generally considered a low-grade renal epithelial neoplasm. However, MTSCC with distant metastases often shows a poor prognosis. This is the first reported case of cytoreductive nephrectomy after nivolumab plus ipilimumab combination treatment. Case Report: A 26- year-old man had a 72-mm tumor at the left kidney with multiple osteolytic bone metastases. A biopsy of the renal tumor and bone metastases resulted in the diagnosis of MTSCC of the kidney with bone metastases. After nivolumab plus ipilimumab combined treatment, he underwent cytoreductive nephrectomy. The excised specimen showed higher PD-L1 expression in the spindle components than in the tubular components, but CD4- and CD8-positve T-cells showed greater infiltration in the tubular components than the spindle components. Conclusion: Combination immunotherapy of nivolumab and ipilimumab may be an effective treatment option for metastatic MTSCC of the kidney. [ABSTRACT FROM AUTHOR]

Introduction Bilateral renal cell carcinomas with different histological types are rare. We report herein the first description of bilateral renal carcinomas with clear cell renal cell carcinoma and mucinous tubular and spindle cell carcinoma occurring synchronously. Case presentation A 62‐year‐old man was referred to our hospital with bilateral renal tumors. The tumors on each side showed different findings from both contrast‐enhanced computed tomography and magnetic resonance imaging. The tumors were partially resected. Histopathological and immunohistochemical examination of the left renal tumor diagnosed clear cell renal carcinoma. Histopathological and immunohistochemical examination of the right renal tumor diagnosed mucinous tubular and spindle cell carcinoma. Conclusion We encountered a case with clear cell renal cell carcinoma and mucinous tubular and spindle cell carcinoma occurring simultaneously in bilateral kidneys.

Mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney is a rare type of kidney cancer. Accurate diagnosis depends on pathological examination. A huge left renal tumor was incidentally found by computed tomography (CT) examination of a 52-year-old lady. She underwent Laparoscopic radical left nephrectomy. The postoperative pathological diagnosis is Mucinous tubular and spindle cell carcinoma. Eight months later, she showed no signs of recurrence.

Mucinous tubular and spindle cell carcinoma (MTSCC) shows significant overlap with papillary renal cell carcinoma (PRCC), and harbor recurrent copy-number alterations (CNA). We evaluated 16 RCC with features suggestive of MTSCC using chromosomal microarrays. The cohort was comprised of 8 females and males, each, with an age range of 33-79 years (median, 59), and a tumor size range of 3.4-15.5 cm (median, 5.0). Half the tumors were high-grade (8/16, 50%) with features such as necrosis, marked cytologic atypia, and sarcomatoid differentiation, and 5/16 (31%) were high stage (≥pT3a). Three (of 16, 19%) cases had a predominant (>95%) spindle cell component, whereas 5/16 (31%) were composed of a predominant (>95%) epithelial component. Most cases (12/16, 75%) exhibited a myxoid background and/or extravasated mucin, at least focally. Twelve (of 16, 75%) cases demonstrated CNA diagnostic of MTSCC (losses of chromosomes 1, 4, 6, 8, 9, 13, 14, 15, and 22). In addition, 2 high-grade tumors showed loss of CDKN2A/B, and gain of 1q, respectively, both of which are associated with aggressive behavior. Three (of 16, 19%) cases, demonstrated nonspecific CNA, and did not meet diagnostic criteria for established RCC subtypes. One (of 16, 6%) low-grade epithelial predominant tumor (biopsy) demonstrated characteristic gains of 7, 17, and loss of Y, diagnostic of PRCC. MTSCC can be a morphologically heterogenous tumor. Our study validates the detection of characteristic chromosomal CNA for diagnostic use that may be useful in challenging cases with unusual spindle cell or epithelial predominant features, as well as in high-grade tumors., Competing Interests: Declaration of competing interest The authors of this article have no relevant financial relationships with commercial interests to disclose., (Copyright © 2024 Elsevier Inc. All rights reserved.)

We report a case of unusually aggressive behavior of a mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney with no sarcomatoid changes. A 43-year-old man was referred to our hospital for a mass on his left kidney. Computed tomography revealed a tumor at the upper pole of the kidney and swollen lymph nodes. Left radical nephrectomy with lymph node dissection was performed and the tumor was diagnosed as MTSCC. Peritoneal dissemination was detected 4 months after the surgery. The patient received systemic treatments, which were not effective. He finally died of the disease 12 months after the surgery.

Mucinous tubular and spindle cell carcinoma (MTSCC) is rare in renal cell carcinoma (RCC) and usually demonstrates a low nuclear grade and a better prognosis compared with other RCCs. The authors present a case report of MTSCC containing an area of Fuhrman nuclear grade 3, in addition to an area with a micropapillary pattern. An 82-year-old man consulted a hospital due to macrohematuria, and a tumor in the right kidney was detected. The tumor was resected and histologically examined. The tumor consisted of various growth patterns: Elongated tubular structure, a papillary structure containing a micropapillary pattern and solid pattern with spindle cells. The tumor cells demonstrated Fuhrman nuclear grades 2 and 3. Invasion into the lymph vessel and metastasis into the regional lymph node were observed. Thus, the tumor was diagnosed as a high grade MTSCC. Five months following resection, a computed tomography scan suggested metastasis of the tumor into the para-aortic lymph nodes and liver, and the patient succumbed to brain metastasis. When MTSCC of kidney is observed, careful histological observation is important to avoid missing a high nuclear grade area. [ABSTRACT FROM AUTHOR]

Mucinous tubular and spindle cell carcinoma (MTSCC) is a relatively rare renal epithelial neoplasm. Although MTSCC is considered to be a low-grade and indolent neoplasm, aggressive cases have been recently reported. The present study discussed two additional cases of high-grade MTSCC causing multiple distant metastases with a fatal course. In case 1, a 71-year-old patient presented with hematuria and pyuria. Computed tomography (CT) scan of the right kidney revealed a mass lesion, for which partial nephrectomy was performed. However, a follow-up CT imaging revealed distant metastases in the liver, the paraaortic lymph nodes and the bone. Despite molecular targeted therapy and irradiation, the patient succumbed due to tumor progression. In case 2, a 64-year-old patient presented with an incidentally identified mass lesion in the right kidney. A laparoscopic nephrectomy was performed, and a follow-up CT imaging revealed metastases in the skin and lungs. The cytology of pleural effusion revealed pleuritis carcinomatosa. Histologically, both cases were diagnosed as mucin-poor MTSCC with high-grade transformation, which comprised uniform tumor cells primarily forming slender tubules. The tumors contained low- and high-grade regions. In addition, venous invasion and necrosis were observed. The tumor cells also demonstrated increased Ki-67 labeling indices and cellular tumor antigen p53 (p53) nuclear accumulation. High-grade transformation, large tumor size, necrosis, venous invasion, high Ki-67 labeling index and p53 nuclear accumulation are generally predictive findings for aggressive behavior of malignant tumors. In the current report, it was emphasized that MTSCC possesses a wide spectrum of clinicopathological features. Thus, careful postoperative investigation is required for MTSCC with high-grade elements due to its aggressive nature. [ABSTRACT FROM AUTHOR]

Mucinous tubular and spindle cell carcinoma is a rare tumor defined in the 2004 WHO classification as a new entity. It is characterized by a relatively indolent behavior We report the case of a 60-year old woman presenting with lumbar pain. CT scan showed left renal mass measuring 55 x 40 mm. The patient underwent left partial nephrectomy. Macroscopic examination showed a well limited fleshy tumor with hemorrhagic or necrotic elements. Histological examination confirmed low grade mucinous tubular and spindle cell carcinoma. Immunohistochemistry revealed cytokeratin positive cells (CK 7 and CK 19), epithelial membrane antigen positive cells (EMA), and CD10-negativity cells. Patient's evolution was favorable, with a follow-up period of 6 months. [ABSTRACT FROM AUTHOR]

Background: Mucinous tubular and spindle cell carcinoma (MTSC) is a rare and newly described type of renal cell carcinoma (RCC) with relatively indolent behavior. Although there are small series of this clinical entity in the literature, its histogenetic origin or line of differentiation remains unclear. Patients and Methods: A 67-year-old woman was hospitalized for flank pain; imaging studies revealed a 6.5-cm mass in the right kidney. She was referred for fine needle aspiration of the lesion, which showed an epithelial tumor with round to oval nuclei associated with strands of metachromatic stromal tissue. Cytopathologic diagnosis was consistent with RCC. Results: Subsequent right heminephrectomy was performed and the surgical pathology specimen showed an MTSC of the kidney. The patient has done well postoperatively, with 24 months of benign follow-up. Conclusion: A precise differential diagnosis between MTSC and other renal carcinomas (e.g. papillary RCC with sarcomatoid transformation) is important for predicting patient prognosis. Even though MTSC is a rare cause of renal masses, it should be included in the differential diagnosis, especially because its imaging might be misleading, mimicking other benign renal diseases. Heminephrectomy is the preferred treatment in these subjects.

Background: Mucinous tubular and spindle carcinoma (MTSCC) of kidney is a rare, low-grade polymorphic tumor. Recent studies have described a wide morphology spectrum of this tumor. Aim: To report the clinico-pathologic features of six cases of MTSCC of kidney. Materials and Methods: Six cases of MTSCC of kidney were studied and literature was reviewed. Immunohistochemistry was done by Envision method. Results: The age of the patients ranged from 44 to 84 years (mean 58.5 years). Four patients were males and two were females. The tumor was located in the left kidney in four cases and in the right kidney in two cases. The tumor size ranged from 4.5 to 15 cm (mean 6.4 cm). All tumors exhibited an admixture of tubules, spindle cells, and mucinous stroma in variable proportions. Tubules were predominant in five cases and spindle cells in one case. Psammomatous calcifications, papillations, and necrosis were seen in two cases. Collections of foamy histiocytes were noted in four cases. Cytoplasmic vacuoles and osseous metaplasia were seen in one case each. All cases were Fuhrman′s nuclear grade II. Five cases were of stage pT1, and one was pT3. All cases stained positive for alcian blue at pH 2.5. Immunohistochemical stain CK7 was positive in all cases and CD10 was positive in 1/1 case. All patients were alive and well at follow-up of 12-59 months (mean 33.5 months). No metastases were detected. Conclusions: We report six cases of MTSCC of kidney, a rare distinct variant of RCC, with a favorable prognosis. A male predominance was seen in our cases. MTSCC shares histologic and immunohistochemical overlap with papillary renal cell carcinoma (PRCC) and cytogenetic analysis should be performed in difficult cases to avoid a misdiagnosis.

Background/aim: Mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney is a rare histological type of renal cell carcinoma (RCC). There are few reports of MTSCC occurring in renal transplant recipients (RTRs). The aim of this study was to report a case of long-term survival of a RTR with metastatic MTSCC of the kidney with sarcomatoid changes., Case Report: A 53-year-old male with a left retroperitoneal tumor was referred to our department. He had been receiving hemodialysis since 1991 and underwent kidney transplantation in 2015. Computed tomography (CT) revealed suspected RCC, and a radical nephrectomy was performed in June 2020. Pathological findings revealed MTSCC with sarcomatoid changes. After the surgery, multiple metastases appeared in the bilateral adrenals, skin, para-aortic lymph nodes, muscles, mesocolon, and liver. We treated the patient with metastasectomy, radiation therapy, and sequential systemic therapy with tyrosine kinase inhibitors (TKI). Two years after the initial surgery, the patient died of cancer while controlling its progression., Conclusion: We report a RTR with aggressive and metastatic MTSCC with sarcomatoid changes, resulting in a longer survival time relative to multimodal therapy., (Copyright © 2023, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.)