Mucinous tubular and spindle cell renal cell carcinoma: a review of clinicopathologic aspects

Mucinous Tubular and Spindle Cell Carcinoma: Case Report and Literature Review

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare type of renal cell carcinoma (RCC) recognized as an independent entity in the latest WHO (World Health Organization) classification. We here report a case of a 51-year-old female patient with MTSCC, who presented with abdominal pain and left lower pole kidney lesion on the computed tomography scan. A robotic-assisted laparoscopic partial nephrectomy was performed. The diagnosis was confirmed on histopathological examination. MTSCC is rare and generally indolent. Either partial or radical nephrectomy is usually curative. The prognosis is usually favorable. However, occasionally, MTSCC could demonstrate aggressive features requiring systemic therapy. There are also several mimickers of MTSCC, which carry different prognostic and treatment profiles. Histological, immunohistochemical, and molecular genetic profile are useful in diagnosing the disease.

Artificial intelligence links CT images to pathologic features and survival outcomes of renal masses

Treatment decisions for an incidental renal mass are mostly made with pathologic uncertainty. Improving the diagnosis of benign renal masses and distinguishing aggressive cancers from indolent ones is key to better treatment selection. We analyze 13261 pre-operative computed computed tomography (CT) volumes of 4557 patients. Two multi-phase convolutional neural networks are developed to predict the malignancy and aggressiveness of renal masses. The first diagnostic model designed to predict the malignancy of renal masses achieves area under the curve (AUC) of 0.871 in the prospective test set. This model surpasses the average performance of seven seasoned radiologists. The second diagnostic model differentiating aggressive from indolent tumors has AUC of 0.783 in the prospective test set. Both models outperform corresponding radiomics models and the nephrometry score nomogram. Here we show that the deep learning models can non-invasively predict the likelihood of malignant and aggressive pathology of a renal mass based on preoperative multi-phase CT images.

Renal mass biopsy - a practical and clinicopathologically relevant approach to diagnosis

Advancements in imaging modalities have increased the frequency of renal mass discovery. Imaging has typically been considered sufficient to guide management for a large proportion of these tumours, but renal mass biopsies (RMBs) have an increasing role in determining malignancy and can be a valuable tool for preventing unnecessary surgery in patients with benign tumours. A structured approach should be used to help to navigate the expanding repertoire of renal tumours, many of which are molecularly defined. In terms of tumour subtyping, the pathologist's strategy should focus on stratifying patients into clinically different prognostic groups according to our current knowledge of tumour behaviour, including benign, low-grade or indolent, intermediate malignant or highly aggressive. Crucial pathological features and morphological mimicry of tumours can alter the tumour's prognostic group. Thus, pathologists and urologists can use RMB to select patients with tumours at a reduced risk of progression, which can be safely managed with active surveillance within a tailored imaging schedule, versus tumours for which ablation or surgical intervention is indicated. RMB is also crucial in the oncological setting to distinguish between different high-grade tumours and guide tailored management strategies.

Renal Leiomyoma in a Female Adult: A Histopathological Case Report

Renal leiomyomas are rare benign mesenchymal tumors that arise from the smooth muscle cells in the renal capsule, renal pelvis, and the smooth muscles of vessels in the kidney. They are usually found by accident during autopsies or on different imaging modalities made on other occasions. The clinical presentation may include hematuria and abdominal or flank pain, although renal leiomyomas are most frequently asymptomatic. This case concerns a 45-year-old woman with an asymptomatic tumor mass in the left kidney, discovered incidentally on an outpatient CT scan conducted on an unrelated occasion. Histological examination revealed well-demarcated tumor formation on regular hematoxylin and eosin (H&E) staining consisting of intersecting fascicles of spindle cells with blunt-ended, cigar-shaped nuclei and eosinophilic cytoplasm. The neoplasm showed no mitotic activity. Immunohistochemistry (IHC) was performed to exclude different spindle cell pathologies, such as solitary fibrous tumor of the kidney, primary leiomyosarcoma, and, less probably, sarcomatoid variants of renal cell carcinoma (RCC). Tumor cell cytoplasm was positive for h-caldesmon, smooth muscle actin (SMA), and desmin. The proliferation index Kiel-67 (Ki-67) was evaluated as less than 1%. Considering the microscopic description and the IHC results, the neoplasm was interpreted as a renal leiomyoma. In light of the rarity of these tumors, pathologists should consider differential diagnosis with precision. In challenging cases, immunohistochemical examination can be beneficial to distinguish between several spindle cell renal neoplasms, such as solitary fibrous tumor, leiomyosarcoma, sarcomatoid variant of RCC, fat-poor angiomyolipoma, benign peripheral nerve sheath tumors, renomedullary interstitial cell tumor, benign fibrous histiocytoma, primary angiosarcoma, mucinous tubular and spindle cell renal cell carcinoma (MTSRCC).

Renal cell carcinoma

The landscape of the management of renal cell carcinoma has evolved substantially in the last decade, leading to improved survival in localised and advanced disease. We review the epidemiology, pathology, and diagnosis of renal cell carcinoma and discuss the evidence for current management strategies from localised to metastatic disease. Developments in adjuvant therapies are discussed, including use of pembrolizumab-the first therapy to achieve overall survival benefit in the adjuvant setting. The treatment of advanced disease, including landmark trials that have established immune checkpoint inhibition as a standard of care, are also reviewed. We also discuss the current controversies that exist surrounding the management of metastatic renal cell carcinoma, including the use of risk assessment models for disease stratification and treatment selection for frontline therapy. Management of non-clear cell renal cell carcinoma subtypes is also reviewed. Future directions of research, including a discussion of ongoing clinical trials and the need for reliable biomarkers to guide treatment in kidney cancer, are also highlighted.

Mucinous tubular and spindle renal cell carcinoma revealed by a trauma of the kidney: a case report

BACKGROUND

Mucinous tubular and spindle cell carcinoma is a rare renal tumor. It has been recognized as a distinct entity in the 2004 World Health Organization tumor classification. Since then, several dozen of these tumor have been reported with additional complementary morphologic characteristics, immunohistochemical profile, and molecular genetic features that have further clarified its clinicopathologic aspects.

CASE PRESENTATION

We report the case of a 52-year-old male African patient who was found to have a mucinous tubular and spindle renal cell carcinoma on a nephrectomy specimen for a severe kidney trauma.

CONCLUSIONS

This tumor has a histological spectrum ranging from low to high grade, which includes sarcomatoid differentiation that can confer the tumor an aggressive clinical course.

Indolent mucinous tubular and spindle cell carcinoma of the kidney: A case report and review of the literature

Mucinous tubular and spindle cell carcinoma of the kidney (MTSCC) is a rare subtype of renal cancer. It consists of tubules separated by mucus stroma and a spindle cell. Few cases have been reported; thus, the imaging features of MTSCC are not well characterized. An MTSCC in the left kidney of a 65-year-old woman was incidentally discovered during a medical checkup. A review of the patient's medical history revealed that this kidney lump had an indolent growth process. The current study presented this case and reviewed the pathological features, imaging findings and treatment options of MTSCC to strengthen the recognition of this rare renal neoplasm by radiologists.

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.

Contemporary Clinical Definitions, Differential Diagnosis, and Novel Predictive Tools for Renal Cell Carcinoma

Despite significant progress regarding clinical detection/imaging evaluation modalities and genetic/molecular characterization of pathogenesis, advanced renal cell carcinoma (RCC) remains an incurable disease and overall RCC mortality has been steadily rising for decades. Concomitantly, clinical definitions have been greatly nuanced and refined. RCCs are currently viewed as a heterogeneous series of cancers, with the same anatomical origin, but fundamentally different metabolisms and clinical behaviors. Thus, RCC pathological diagnosis/subtyping guidelines have become increasingly intricate and cumbersome, routinely requiring ancillary studies, mainly immunohistochemistry. Meanwhile, RCC-associated-antigen targeted systemic therapy has been greatly diversified and emerging, novel clinical applications for RCC immunotherapy have already reported significant survival benefits, at least in the adjuvant setting. Even so, systemically disseminated RCCs still associate very poor clinical outcomes, with currently available therapeutic modalities only being able to prolong survival. In lack of a definitive cure for advanced RCCs, integration of the amounting scientific knowledge regarding RCC pathogenesis into RCC clinical management has been paramount for improving patient outcomes. The current review aims to offer an integrative perspective regarding contemporary RCC clinical definitions, proper RCC clinical work-up at initial diagnosis (semiology and multimodal imaging), RCC pathological evaluation, differential diagnosis/subtyping protocols, and novel clinical tools for RCC screening, risk stratification and therapeutic response prediction.

Mucinous tubular and spindle cell carcinomas of the kidney (MTSCC-Ks): CT and MR imaging characteristics

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 ADC_tumor-to-ADC_{renal 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.

Mucinous tubular and spindle cell carcinoma with high-grade transformation: case report

Background

Mucinous tubular and spindle cell carcinoma (MTSCC) is a type of renal cell carcinoma (RCC) described as an entity with low-grade and low malignant potential. This report presents a high-grade transformation of MTSCC which is an uncommon finding in this subtype of RCC. Although most reported cases showed low malignant potential and good prognosis after surgical resection, a small subset of patients has been reported with aggressive phenotype and fatal outcome.

Case presentation

A case of a 23-year-old male is discussed with an incidental renal mass in the left kidney after a workup of bilateral flank pain. Morphologically, the tumor was composed of tubular structures lined by cuboidal cells mixed with spindle cells and sarcomatoid change was present in the tumor. Previously sarcomatoid change has been mostly reported along with conventional morphology in other common type of RCC with a worse prognosis.

Conclusions

The aim of this report is to draw the attention of pathologists and clinicians to the importance of high grade MTSCC owing to the unfavorable prognosis.

Rare anti-VEGFR therapy-induced toxicity and long-term response to immunotherapy in a rare non-clear cell renal cell carcinoma patient

Advanced non-clear cell renal cell carcinoma (nccRCC) has a poor prognosis and clinical data on the therapeutic options currently available, including immunotherapy, are generally limited highlighting an unmet clinical need. Moreover, the onset of rare adverse events raises the need of a better therapeutic management of limited treatment options. We report the clinical case of a 63-year-old man with the diagnosis of metastatic mucinous tubular and spindle cell carcinoma, a rare nccRCC, with sarcomatoid differentiation who developed two episodes of posterior reversible encephalopathy syndrome (PRES) to first-line sunitinib. It appeared after 5 months the start of the targeted therapy and reappeared at the reintroduction of the therapy. PRES is a rare and unusual adverse event to anti-vascular endothelial growth factor receptor (VEGFR) therapies, which is characterized by acute neurological disorders along with typical changes on neurological imaging, especially MRI. Moreover, this rare histotype of RCC experienced a long-term response to immunotherapy which is lasting more than 2 years. This clinical case is interesting for its rarity as a rare neurological adverse event developed twice in a rare type of RCC which also experienced an unusual long-term benefit to immunotherapy.

MR characteristics of mucinous tubular and spindle cell carcinoma (MTSCC) of the kidney: comparison with clear cell and papillary subtypes of renal cell carcinoma

PURPOSE

To describe MR features of mucinous tubular spindle cell carcinoma (MTSCC) of the kidney that may help differentiate from clear cell renal cell carcinoma (ccRCC) and papillary RCC (pRCC).

METHODS

15 MTSCCs were retrospectively evaluated by MR with T2-weighted image without fat suppression (n = 15) and dynamic contrast-enhanced (DCE), fat-suppressed T1-weighted GRE (n = 11). Size-matched ccRCC (n = 30) and pRCC (n = 30) were evaluated as control. T2 ratio was calculated as the signal intensity (SI) ratio of the lesion to the renal cortex on T2W images. Enhancement ratio (ER) was calculated as (SI_post - SI_pre)/(SI_pre), where SI_pre (SI_post) is the SI of the entire lesion on each phase of DCE images. Early nodular enhancement was subjectively evaluated in MTSCC. T2 ratio and ER were compared using the Mann-Whitney U test with Bonferroni correction.

RESULTS

The mean value of T2 ratio was highest in ccRCC (1.24), followed by MTSCC (1.02), and pRCC (0.84). Difference of T2 ratio was significant between ccRCC and pRCC (p < 0.001), but not between MTSCC and ccRCC (p = 0.4) or between MTSCC and pRCC (p = 0.2). The mean ER of MTSCC, ccRCC and pRCC were 1.33, 1.53 and 0.38 in corticomedullary phase (CMP), 1.60, 1.61 and 0.69 in nephrographic phase (NGP) and 1.79, 1.35 and 0.77 in excretory phase (EP), respectively. ERs were significantly different between MTSCC and pRCC in CMP (p = 0.01), NGP (p = 0.003), and EP (p = 0.002). Early nodular enhancement was observed in 4/11 MTSCC (36%), 17/30 ccRCC (57%), and 2/30 pRCC (7%).

CONCLUSIONS

MTSCC has distinct MR features that can help differentiate from ccRCC and pRCC. MTSCC enhances more avidly compared to pRCC and shows gradual progressive enhancement.

Metastatic mucinous tubular and spindle cell carcinoma of the kidney responding to nivolumab plus ipilimumab

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.

Two Rare Entities in One Patient: Mucinous Tubular and Spindle Cell Carcinoma of the Kidney and Peritoneal Adenomyomas

Mucinous tubular and spindle cell carcinoma of the kidney is a rare subtype of renal cell carcinoma, that is believed to portend a favorable prognosis. Adenomyomas are benign tumors that typically arise from the myometrium. Extrauterine adenomyomas are extremely rare, with only a few cases reported in the literature. Here, we present an unusual case of a 46-year-old woman, with an incidentally detected bulky interpolar left kidney mass measuring 12 cm and multiple lobulated coalescent peritoneal nodules in the large epiploon suspicious for peritoneal carcinomatosis. A biopsy of the lesions revealed a mucinous tubular and spindle cell carcinoma of the kidney and extrauterine adenomyomas of the peritoneum. A left radical nephrectomy was performed and long-term hormone therapy with gonadotropin-releasing hormone agonists was prescribed. The purpose of this article is to focus on these two rare lesions, review the current literature, illustrate their key imaging findings along with pathologic correlation, as well as to discuss the differential diagnosis and clinical management.

Glucagon-producing mucinous tubular and spindle cell variant of renal cell carcinoma with paraneoplastic diabetes: Case report and review of literature

Renal cell carcinoma (RCC) is known as the internist tumor because of the myriad paraneoplastic manifestations associated with it. One of the rarely described paraneoplastic manifestations associated with this malignancy is hyperglycemia. Only 11 cases in the English and Japanese literature have been reported. We report the occurrence of paraneoplastic hyperglycemia with a rare variant: mucinous tubular and spindle cell variant of RCC. To the best of our knowledge, the association of paraneoplastic hyperglycemia with this variant has not been reported earlier.

Mucinous tubular and spindle cell carcinoma: A difficult diagnosis

Mucinous Tubular and Spindle Cell Carcinoma (MTSCC) is infrequently seen renal malignancy with favorable outcome, when diagnosed in the early stage. Once out of kidney it is have lethal course. Radiologically MTSCC is heterogeneously hypo-enhancing renal mass in delayed phase, may mimic to papillary renal cell carcinoma and in histopathology showed these tumoral cells shows complex immunophenotype expression. As this does not show enhancement pattern of common renal cell carcinomas, radiological diagnosis may be challenging. Histopathological reporting is also tedious indeed necessary to reach definitive diagnosis, which help in tailoring follow up and prognosis. Metastatic disease has dismal outcome and responds poorly with adjuvant therapy and patient succumbs within short span of time.

Update on Renal Neoplasms: Clinicopathologic-Radiologic Correlation With Case-Based Examples

OBJECTIVE. This article provides a brief overview of the clinicopathologic and radiologic correlation of 12 renal neoplasms, encompassing the conventional subtypes of renal cell carcinoma and a few of the newly recognized subtypes from the 2016 World Health Organization classification of renal tumors. In addition, we touch upon infrequent neoplasms that may enter the differential diagnosis of a renal mass, with corresponding radiologic and gross images and histologic findings of case-based examples. CONCLUSION. Familiarity with the radiologic and pathologic characteristics of renal cell carcinoma and other renal neoplasms is important to correctly identify and treat these masses.

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

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.

Case of renal mucinous tubular and spindle cell carcinoma with high nuclear grade

Introduction

Renal mucinous tubular and spindle cell carcinoma is a rare subtype of renal cell carcinoma newly added to the World Health Organization classification in 2004. Although it has been considered as a tumor with good prognosis, aggressive cases have recently been reported.

Case presentation

A 52‐year‐old man was diagnosed as having left renal cell carcinoma. Open radical left nephrectomy and left‐sided pelvic lymph nodes dissection were performed. Pathological diagnosis revealed a renal mucinous tubular and spindle cell carcinoma with high nuclear grade and extra‐regional lymph nodes metastasis classified as pT3aN0M1. After nephrectomy, metastasis at second lumbar vertebra and lymph nodes recurrence were occurred.

Conclusion

This tumor with high nuclear grade may be potentially aggressive and carries a poor prognosis.

Mucinous Tubular and Spindle Cell Carcinoma: A Review of Histopathology and Clinical and Prognostic Implications

Mucinous tubular and spindle cell carcinomas are rare kidney tumors with generally indolent behavior. As the name suggests, classic histomorphology reveals bland spindle cells, tubules, and mucinous stroma. Uncommon histologic features include mucin-poor stroma, high nuclear grade, cellular pleomorphism, and presence of necrosis. Rare cases can show aggressive growth and distant metastasis. Mucinous tubular and spindle cell carcinoma has characteristic chromosomal abnormalities and the molecular signature remains the same, irrespective of the varied histomorphology.

Imaging of Unusual Renal Tumors

PURPOSE OF REVIEW

Renal masses are a wide entity and a common finding in clinical practice. Detection of these masses has increased in the last years, yet mortality rates have slightly decreased.

RECENT FINDINGS

According to the World Health Organization classification, there are 8 types, 51 subtypes, and a lot more subsequent subclassifications of renal tumors. Histopathological analysis should always be assessed for final diagnosis of theses tumors. However, imaging can be an important diagnostic guidance. The most common diagnoses of renal tumor are clear cell carcinoma, papillary renal cell carcinoma, angiomyolipoma, and transitional cell carcinoma. Nonetheless, a considerable variety of particular tumors can arise from the kidney, challenging the expertise of radiologists and urologists on this subject. The awareness of these unusual entities is vital for professionals working at a complex medical facility with greater volume of patients. We hereby present uncommon renal tumors and its pathological and radiological features.

Huge mucinous tubular and spindle cell carcinoma of kidney: A rare case report and literature review

RATIONALE

Mucinous tubular and spindle cell carcinoma (MTSCC) is a variant of renal cell carcinoma newly added to the WHO classification in 2004. It is a rare variant of renal cell carcinoma and sometimes it is not easy to distinguish MTSCC from papillary renal cell carcinoma, chromophobe renal cell cancer, etc. The prognosis of MTSCC is favorable after surgical resection.

PATIENT CONCERNS

A 45-year-old male patient presented with a right renal mass that was detected on ultrasonography incidentally. The computed tomography scan showed a huge homogenous mass with patchy calcification in the central area, and the lesion was slightly enhanced after contrast injection.

DIAGNOSES

According to postoperative pathology, the patient was diagnosed with MTSCC.

INTERVENTIONS

The patient underwent an open transabdominal radical resection of right kidney and right retroperitoneal lymph node dissection.

OUTCOMES

The surgical outcomes were good, and no recurrence or metastasis was observed during the follow-up.

LESSONS

MTSCC is a rare malignancy of the kidney and the prognosis is usually favorable. Preoperative enhanced CT and MRI can help differentiate MTSCC from other renal tumors, so as to provide a more suitable surgical approach for those who need to retain renal function as much as possible.

The Probability of Aggressive Versus Indolent Histology Based on Renal Tumor Size: Implications for Surveillance and Treatment

BACKGROUND

While the probability of malignant versus benign histology based on renal tumor size has been described, this alone does not sufficiently inform decision-making in the modern era since indolent malignant tumors can be managed with active surveillance.

OBJECTIVE

To characterize the probability of aggressive versus indolent histology based on radiographic tumor size.

DESIGN, SETTING, AND PARTICIPANTS

We evaluated patients who underwent radical or partial nephrectomy at Mayo Clinic for a pT1-2, pNx/0, M0 solid renal tumor between 1990 and 2010. Pathology was reviewed by one genitourinary pathologist. High-grade clear-cell renal cell carcinoma (RCC), high-grade papillary RCC, collecting duct RCC, translocation-associated RCC, hereditary leiomyomatosis RCC, unclassified RCC, and malignant non-RCC tumors were all considered aggressive, as well as any tumors demonstrating coagulative necrosis (except low-grade papillary RCC) or sarcomatoid differentiation. The remaining benign and malignant tumors were considered indolent.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Cancer-specific survival (CSS) was estimated using the Kaplan-Meier method. Logistic regression models were used to estimate the probability of malignant and aggressive histology based on tumor size. Sex-stratified analyses were also performed.

RESULTS AND LIMITATIONS

Of the 2650 patients included, there were 1860 patients with indolent tumors (300 benign; 1560 malignant) and 790 with aggressive tumors. The 10-yr CSS was 96% for indolent malignant tumors and 81% for aggressive malignant tumors. The predicted percentages of any malignant histology as well as aggressive histology increased with tumor size. Specifically, 2cm, 3cm, and 4cm tumors have an estimated 84%, 87%, and 88% likelihood of malignancy, respectively, and an 18%, 24%, and 29% likelihood of aggressive histology, respectively. For any given tumor size, men had a greater chance of aggressive histology than women. Potential limitations of this observational surgical cohort include selection bias.

CONCLUSIONS

We present tumor size-based estimates of the probability of aggressive histology for renal masses. This information should be useful for initial patient counseling and management.

PATIENT SUMMARY

Active surveillance is an option for kidney masses, even if they are malignant. Beyond knowing whether the mass is benign or cancer, it is important to know whether or not it is an aggressive tumor. This study presents tumor size-specific and sex-specific estimates of the probability of cancer overall and aggressive cancer among patients with a kidney mass in order to aid with initial decision-making.

Renal Mucinous Tubular and Spindle Cell Carcinoma Shows a High Uptake on 18F-FDG PET/CT

We herein report a rare case of mucinous tubular and spindle cell carcinoma (MTSCC) in an 80-year-old woman. A well circumscribed tumor located on the right kidney was discovered incidentally as a result of screening non-contrast CT. Fluorodeoxyglucose positron emission tomography (FDG PET)/CT showed the increased tracer accumulation in the tumor. The histological diagnosis was MTSCC, which is a rare and only recently established subtype of the malignant renal cell carcinoma (RCC). The present case suggests the clinical benefit of a high uptake of FDG combined with enhanced contrast CT in the differentiation of MTSCCs and other RCCs.

Mucin-Poor Mucinous Tubular and Spindle Cell Carcinoma of the Kidney Presented with Multiple Metastases Two Years after Nephrectomy: An Atypical Behaviour of a Rare, Indolent Tumour

Background

Mucinous tubular and spindle cell carcinoma (MTSCC) is a rare type of renal cell carcinoma, whose clinical behaviour and metastatic potential have not been fully elucidated to date. There are only a few metastatic cases in the literature, which all either featured sarcomatoid differentiation or were synchronously metastasised at diagnosis.

Case Presentation

We report a case of a 49-year-old male with end-stage kidney disease on dialysis, presenting with multiple osseous metastases of a mucin-poor variant of MTSCC of the kidney, without sarcomatoid differentiation, two years after bilateral nephrectomy for papillary renal cell carcinoma (RCC) at a curable stage. After retrospectively reexamining the initial nephrectomy specimens, the tumour of the right kidney was also diagnosed as a mucin-poor variant of MTSCC, while the tumour of the left kidney was confirmed as a papillary RCC.

Conclusions

It is proposed that MTSCC can be associated with end-stage renal disease and that particularly the mucin-poor variant is easily confused with papillary renal cell carcinoma, as happened in this case. Although it is considered as a relatively indolent malign entity, it can metastasise even years after successful primary surgical treatment. This implies, besides accurate diagnosis, that MTSCC patients should be monitored closely in the follow-up period.

Mucin-poor and aggressive mucinous tubular and spindle cell carcinoma of the kidney: Two case reports

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.

[Mucinous tubular and spindle cell carcinoma: a rare renal tumor]

Le carcinome tubulo-mucineux et fusiforme désigne une tumeur rare décrite dans la classification OMS 2004 comme une nouvelle entité. Elle est reconnue de comportement relativement indolent. Nous rapportons l'observation d'une femme âgée de 60 ans qui présentait des douleurs lombaires, et chez qui la tomodensitométrie a révélé la présence d'une masse rénale gauche mesurant 55 x 40 mm. La patiente a été traitée par néphrectomie partielle gauche dont l'examen macroscopique a montré la présence d'une tumeur bien limitée d'aspect charnu avec des remaniements hémorragiques et nécrotiques. L'étude histologique a confirmé le carcinome tubulo-mucineux et à cellules fusiformes de bas grade. L'immunohistochimie a révélé une positivité à la cytokératine (CK 7 et CK 19) et à l'antigène des membranes épithéliales (EMA), et une négativité au CD10. L'évolution était favorable avec un recul de 6 mois.

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.

Smears are important for adequate cytologic diagnosis of kidney lesions

INTRODUCTION

Traditionally at our institution, smears with or without liquid-based cytology (LBC) and core biopsies (CBs) have been obtained by radiologists performing image-guided fine-needle aspiration biopsies (FNABs) of deep organs. Since 2015, however, there has been a shift to providing cytology with samples for LBC only when obtaining CBs. The impression among our institution's cytologists is that LBC alone is less often adequate for diagnosis compared with smears and LBC together. We examined a series of kidney FNABs pre- and post-"LBC only" to evaluate this impression.

MATERIALS AND METHODS

With institutional review board approval, we compared all kidney FNABs from 2012 to those from 2015. We recorded the type(s) of cytology preparation(s), the number of cytology slides, the cytology diagnosis, the concurrent CB diagnosis, and whether there was a subsequent excision and the excision diagnosis. We examined cytology and CB slides as needed.

RESULTS

In 2012, 105 patients underwent 111 kidney biopsies, 109 with smears made. In 2015, 58 patients underwent 62 kidney biopsies, 7 with smears made. In 2012, there were 13 (12%) nondiagnostic (ND) cytology cases and 19 (17%) cases where the cytology and CB diagnoses were discrepant. By comparison, in 2015, there were 20 (32%) ND cytology cases and 21 (33%) discrepant cases.

CONCLUSIONS

There were more cytology slides per case and fewer ND diagnoses in 2012 compared with 2015 (12% versus 32%, respectively, P = 0.001). Concordance was also better in 2012 (83% versus 67%, P = 0.015). We believe that our metrics would improve if we returned to the procedures followed in 2012.

A Case of Severe Ulcerative Colitis with Colonic Dilatation caused by Renal Mucinous Tubular and Spindle Cell Carcinoma

We present a case of ulcerative colitis (UC) in a patient during the first severe relapse with colonic dilatation and coexisting of giant renal tumor. Kidney tumor was constricting on colon and imitating toxic megacolon (TM). The patient with severe acute colitis (SAC) was admitted to the Department of Gastroenterology and Hepatology with inflammatory bowel disease (IBD) diagnosed in the previous month, based on clinical symptoms, endoscopy, and histopathology results. Computed tomography (CT) revealed a giant left kidney tumor without evidence of infiltration, a dilatation of the transverse colon up to 6 cm, and narrow light of the descending colon. There were no signs of intestinal obstruction or perforation. The control X-rays revealed maintaining megacolon, with dilatation of splenic flexure projection up to 6.5 to 7.5 cm. The patient was treated conservatively with no apparent improvement and finally operated on. Intraoperatively, a large tumor of the kidney (12 cm) constricting intestine was revealed. Left-sided nephrectomy and partial resection of the colon with the emergence of a colostomy was performed. The histopathology exam revealed renal mucinous tubular and spindle cell carcinoma (RMTSCC), a very rare malignant kidney tumor of low malignant potential and relative good prognosis. It was identified in the past 20 years. To date, approximately 100 such cases of cancer have been described.

How to cite this article

Kukulska M, Smola I, Halon A, Paradowski L, Poniewierka E, Kempinski R, Annabhani A. A Case of Severe Ulcerative Colitis with Colonic Dilatation caused by Renal Mucinous Tubular and Spindle Cell Carcinoma. Euroasian J Hepato-Gastroenterol 2016;6(2):190-193.

Unusual Case of Coexisting Renal Malignancies: Mucinous Tubular and Spindle Cell Carcinoma Kidney With Sarcomatoid Dedifferentiation

Mucinous tubular and spindle cell carcinoma (MTSCC) is a recent entity introduced in the World Health Organization 2004 Classification. It is a tumour of low malignant potential. MTSCC is a subtype of renal cell carcinoma (RCC), which is characterized by a polymorphous histology, wherein the spindled epithelial cell is an inherent carcinomatous component. We report the case of a 57-year-old man presenting with loin pain and dragging sensation. Imaging revealed a large mass arising from the left kidney. Radical nephrectomy was performed, and histopathology revealed spindle cell elements of MTSCC with low-grade cytology, which occasionally blended with tubular structures in variable mucinous stroma admixed with spindle sarcomatoid cells with marked nuclear pleomorphism, associated with significant necrosis and mitoses of up to 5/10 high-power field. A final diagnosis of MTSCC along with high-grade areas consistent with sarcomatoid dedifferentiation was made. Sarcomatoid dedifferentiation has been well documented in various subtypes of RCC, and its presence signifies a worse prognosis in RCC.