Sarcomatoid conversion of clear cell renal cell carcinoma in relation to epithelial-to-mesenchymal transition

Approximately 8% of clear cell renal cell carcinoma cases contain regions of radically different morphology, demonstrating a mesenchymal appearance histologically resembling sarcomas. These biphasic neoplasms are called sarcomatoid clear cell renal cell carcinoma. Patients diagnosed with sarcomatoid clear cell renal cell carcinoma face a considerably worse prognosis due to an increased propensity for metastasis. In the present study we investigate whether the sarcomatoid conversion of clear cell renal cell carcinoma could be interpreted as linked to the process of epithelial-mesenchymal transition. Using 6 biphasic clear cell renal cell carcinoma cases we show that sarcomatoid clear cell renal cell carcinoma shares characteristic markers associated with loss of von Hippel-Lindau tumor suppressor with conventional clear cell renal cell carcinoma and also exhibits a markedly higher proliferative index. Furthermore the sarcomatoid elements demonstrate an enhanced expression of epithelial-mesenchymal transition related mesenchymal markers as compared with the clear cell renal cell carcinoma counterparts. We further selected a representative case, clinically demonstrating direct overgrowth of the sarcomatoid component into the liver and colon, for extended immunohistochemical characterization, resulting in a further set of positive and negative epithelial-mesenchymal transition markers as well as pronounced transforming growth factor β positivity, indicating that sarcomatoid clear cell renal cell carcinoma may be associated to epithelial-mesenchymal transition. Transforming growth factor β1 exposure of in vitro cultured primary clear cell renal cell carcinoma cells resulted in cells adopting a mesenchymal morphology similar to sarcomatoid clear cell renal cell carcinoma. Corresponding changes in RNA levels for key epithelial-mesenchymal transition markers were also seen. We therefore suggest that sarcomatoid clear cell renal cell carcinoma morphologically and immunohistochemically may represent a completed epithelial-mesenchymal transition and that transforming growth factor β1 could be an important driving force during the sarcomatoid transdifferentiation of clear cell renal cell carcinoma.     

Sarcomatoid Renal Cell Carcinoma Metastatic to the Heart: Report of a Case

An unusual case of metastatic sarcomatoid renal cell carcinoma is presented. Fifteen months after nephrectomy for a typical clear cell carcinoma, a 63-year-old man presented with bilateral pleural effusions, cardiomegaly, and tamponade. A pericardial biopsy showed an anaplastic spindle cell tumor that was strongly keratin positive and showed desmosomes ultrastructurally. The patient died shortly thereafter, and the autopsy revealed massive tumor infiltration of the heart, pulmonary and adrenal metastases, and tumor nodules at the incision site of his nephrectomy. The differential diagnosis of sarcomatoid renal cell carcinoma is discussed.     

Sarcomatoid Renal Cell Carcinoma Metastatic to the Heart: Report of a Case

An unusual case of metastatic sarcomatoid renal cell carcinoma is presented. Fifteen months after nephrectomy for a typical clear cell carcinoma, a 63-year-old man presented with bilateral pleural effusions, cardiomegaly, and tamponade. A pericardial biopsy showed an anaplastic spindle cell tumor that was strongly keratin positive and showed desmosomes ultrastructurally. The patient died shortly thereafter, and the autopsy revealed massive tumor infiltration of the heart, pulmonary and adrenal metastases, and tumor nodules at the incision site of his nephrectomy. The differential diagnosis of sarcomatoid renal cell carcinoma is discussed.     

Mucinous tubular and spindle cell carcinoma of the kidney with sarcomatoid differentiation

We report a unique case of mucinous tubular and spindle cell carcinoma (MTSC) of the kidney with extensive sarcomatoid differentiation, multiple metastases, and a rapidly fatal clinical course. The patient presented with back pain and a pathologic L1 fracture. Diagnostic imaging revealed a large retroperitoneal mass arising from the left kidney and compressing the spinal cord. Radiotherapy and surgery were performed, but the patient died from disease progression three weeks postoperatively. MTSC is a recently recognized entity that is considered to be a low-grade carcinoma with a favorable prognosis. Our case demonstrates that although MTSC is usually a low-grade carcinoma, sarcomatoid differentiation may occur and lead to a fatal course, as in all other types of renal cell carcinomas. Adequate sampling and the exclusion of sarcomatoid differentiation in the spindle cell component are necessary for proper management and prognostication. To our knowledge, this is the first reported case of MTSC with sarcomatoid differentiation and a fatal outcome.     

Osteopontin is differentially expressed in renal cell tumors

ABSTRACT

Osteopontin (OPN) has been shown to play a significant role in regulating the aggressiveness of cancer cells and promote tumor growth. Evaluation of this phosphorylated extracellular glycoprotein expression may help estimate its use as a potential prognostic marker in tumorigenesis of different renal tumors. The objective of the present study was to characterize for the first time the expression pattern of OPN in primary renal tumors and correlate its association to tumor progression and survival. A total of 68 primary renal tumors (clear cell renal cell carcinoma, oncocytoma, renal cell carcinoma, invasive urothelial carcinoma, papillary renal cell carcinoma, chromophobe renal cell carcinoma, papillary urothelial carcinoma) were analyzed by immunohistochemical staining and Western blot methods. Expression of OPN in relation to grading, histologic type of tumor, and survival was statistically assessed. Study data demonstrated that OPN is differentially expressed in various renal tumor cells types. It was shown that OPN is predominantly expressed at the protein level in clear cell renal cell carcinoma when compared to other types of renal tumors. In conclusion, osteopontin may be involved in the pathogenesis of renal tumors. However, the role of OPN expression in predicting the biological response requires further evaluation.     

Immunohistochemistry and lectin histochemistry in sarcomatoid renal cell carcinoma: a comparison with classical renal cell carcinoma

We investigated the expression of various cell markers in renal cell carcinoma, concentrating particularly on the sarcomatoid variety, using lectin and immunohistochemical techniques. The sarcomatoid variant showed stronger staining in a higher proportion of cases for vimentin and reduced positivity for epithelial membrane antigen, in comparison with classical renal cell carcinoma. All sarcomatoid tumours reacted with at least one cytokeratin, enabling them to be distinguished from true renal sarcomas; this is of diagnostic value when a panel of markers is used. Overall a similar pattern of markers is seen in sarcomatoid and classical renal cell carcinoma using lectin and immunohistochemistry, suggesting that the sarcomatoid variant arises as a metaplastic change rather than having a different histogenesis.     

Renal cell carcinoma classification: what matters?

Renal cell carcinoma classification may seem to be increasing dramatically in complexity over the last 10 years. Although integration of morphology, immunohistochemistry, and molecular features continues to refine different tumor types and dissect subgroups from long-established categories of renal cancer, only a select subset of these distinctions are of highest importance for clinical management. In the metastatic setting, distinction of clear cell from non-clear cell renal cancer is important, as there are different treatment pathways for these two groups. Another select handful of tumor types are highly aggressive (sarcomatoid, medullary, collecting duct, and fumarate hydratase-deficient carcinomas), which may necessitate different therapy from other non-clear cell carcinomas. A few tumor types are highly favorable, especially chromophobe carcinoma and clear cell papillary carcinoma (which is likely to be reclassified as a “tumor” rather than carcinoma soon). Still other tumor histologies often imply a hereditary syndrome solely based on their diagnosis, particularly succinate dehydrogenase-deficient and fumarate hydratase-deficient cancers. Although several eosinophilic tumor types with subtly different features have been recently recognized, it is not clear at present that discriminating them from chromophobe carcinoma is critical, as behavior appears to be largely favorable. Therefore, although some aspects of surgical pathology rely heavily on molecular diagnostics, histologic pattern and select immunohistochemical markers can resolve the differential diagnosis in most renal neoplasms, without need for complex molecular analysis.     

Mucinous tubular and spindle cell carcinoma with aggressive histomorphology--a sarcomatoid variant

Mucinous tubular and spindle cell carcinoma (MTSCC) is a recently described renal epithelial tumor. The bland cytomorphology of the spindled component and low-grade behavior help in its differentiation from sarcomatoid renal carcinoma. Sarcomatoid change has been reported in most histologic variants of renal cell carcinoma apart from MTSCC. Herein we report a case of an MTSCC in a 72-year-old female patient with high-grade spindled areas resembling fibrosarcomatous and undifferentiated pleomorphic sarcoma patterns with metaplastic bone. This index case also demonstrates a high proliferation index and extensive necrosis representing the first documented case of sarcomatoid change in MTSCC.     

Spindle and cuboidal renal cell carcinoma,a tumour having frequent association with nephrolithiasis: report of 11 cases including a case with hybrid conventional renal cell carcinoma/ spindle and cuboidal renal cell carcinoma components

AIMS: We present the largest series of an unclassified subtype of renal cell carcinoma, which seems to be a distinct morphological entity and which is sometimes designated as spindle and cuboidal renal cell carcinoma. METHODS AND RESULTS: Eleven cases of spindle and cuboidal renal cell carcinoma were found among 7000 primary renal cell tumours in Pilsen's routine and consultation files. The patients were five men and six women. They ranged in age from 22 to 65 years (mean 56.8). Microscopically, the tumours were composed of two main populations of cells. First, the preponderant type of cells was formed by flattened, spindle cells with sparse cytoplasm. The second cell type was a small cuboidal cell with clear to light eosinophilic cytoplasm. Spindle-shaped cells were arranged in a fascicular pattern often reminiscent of low-grade smooth muscle tumours. Solid areas of spindle cells were also present. Small cuboidal cells formed sparse tubular structures lined by a row of single cells. In addition to all previous published cases of spindle and cuboidal renal cell carcinoma we observed an association of nephrolithiasis in our cases. It was seen in 3/11 of our patients. A previously unreported feature is the occurrence of a conventional renal cell carcinoma component in one of our cases. Seven of our patients are currently well without signs of recurrence or metastasis, one had metastasis in a regional lymph node at the time of nephrectomy, one died of an unrelated condition, and two were lost to follow-up. CONCLUSIONS: We present 11 cases of spindle and cuboidal renal cell carcinoma, which is believed to be a distinctive morphological entity. Our cases were histologically, immunohistochemically and ultrastructurally similar to the previously reported cases of spindle and cuboidal renal cell carcinoma. In contrast to all previously reported cases of spindle and cuboidal renal cell carcinoma, we observed an association with nephrolithiasis in three of our cases; moreover, one of our tumours had a conventional renal cell carcinoma component and another revealed a metastatic focus in a regional lymph node. None of our patients died of the disease. This study confirms that spindle and cuboidal renal cell carcinoma has a low malignant potential.     

The expanding role of renal mass biopsy

Usage of renal mass biopsy has increased in recent years, ranging from selected clinical scenarios to routine implementation in some institutions. Major tasks for the field of diagnostic histopathology include discriminating primary renal cell cancers from other tumors, especially metastases, hematolymphoid tumors, and urothelial carcinoma. Within primary renal cell neoplasms, relevant distinctions include recognizing clear cell papillary renal cell carcinoma, which despite its resemblance to clear cell cancer is nonaggressive, as well as discriminating oncocytoma from chromophobe carcinoma. Helpful immunohistochemical markers include PAX8 for verification of primary renal cell lineage and carbonic anhydrase IX for support of clear cell subtype. Cytokeratin 7 is generally considered the best marker for discriminating oncocytoma from chromophobe renal cell carcinoma, showing only rare positive cells in oncocytoma and greater staining in chromophobe carcinoma. For metastatic tumors, attempting to discriminate clear cell from non-clear cell types may be important for treatment selection.     

Cytokeratin 7: a useful adjunct in the diagnosis of chromophobe renal cell carcinoma

AIMS: The histopathological diagnosis of chromophobe renal cell carcinoma can present a diagnostic challenge, as these tumours can resemble either conventional renal cell carcinoma or oncocytoma. The aim of this study was to determine whether cytokeratin 7 expression is of practical use in the distinction of these three entities. METHODS AND RESULTS: A total of 40 cases previously diagnosed as either chromophobe renal cell carcinoma, conventional renal cell carcinoma or oncocytoma were identified. A representative section of each was stained with H&E and cytokeratin 7. Following independent review of the cases by three pathologists, a consensus diagnosis for each case was reached and the pattern of cytokeratin 7 staining was assessed. There were 12 cases of chromophobe renal cell carcinoma in the study, all of which showed a characteristic peripheral membrane pattern of staining for cytokeratin 7. Seventeen of the 18 cases of conventional renal cell carcinoma studied were negative for cytokeratin 7, while one case showed weak focal staining of <5% of the cells. The 10 cases of oncocytoma showed patchy weak to moderate cytoplasmic expression of cytokeratin 7, without the characteristic peripheral membrane accentuation seen in the chromophobe carcinomas. CONCLUSIONS: Immunohistochemical staining for cytokeratin 7 appears to be a useful adjunct in the diagnosis of chromophobe renal cell carcinoma, and in distinguishing this tumour from both oncocytoma and conventional renal cell carcinoma.     

Alpha-methyl CoA racemase expression in renal cell carcinomas

Alpha-methyl CoA racemase (AMACR), a new molecular marker for prostate cancer, has been recently reported to be one of the most highly expressed genes in papillary renal cell carcinomas (RCCs). We tested the diagnostic usefulness of AMACR antibody in a series of 110 renal tumors: 53 papillary RCCs (33 type 1, 20 type 2); 25 conventional RCCs; 6 chromophobe RCCs; 9 oncocytomas; 5 mucinous tubular and spindle tumors; 2 urothelial carcinomas; 7 angiomyolipomas; and 2 Bellini carcinomas. Immunohistochemical staining was performed on formalin-fixed, paraffin-embedded tissue sections, with a primary prediluted rabbit monoclonal anti-AMACR antibody. Both type 1 and type 2 papillary RCCs exhibited cytoplasmic immunoreactivity for AMACR, with diffuse strong granular staining in 96.4% (53/55) of tumors, without correlation with type or nuclear grade. The 5 mucinous, tubular, and spindle cell carcinomas strongly expressed AMACR, and only 5 of 25 clear cell RCCs and 1 of 9 oncocytomas were focally reactive. The remaining 6 chromophobe RCCs, 5 urothelial carcinomas, and Bellini duct carcinomas showed no immunoreactivity for AMACR. Because high expression of AMACR is found in papillary RCCs (type 1 and 2) and in mucinous, tubular, and spindle cell carcinomas of the kidney, immunostaining for AMACR should be used in conjunction with other markers when histological typing of a renal tumor is difficult.     

Distinct Cytoplasmic Expression of KL-6 Mucin in Chromophobe Renal Cell Carcinoma: A Comparative Immunohistochemical Study with Other Renal Epithelial Cell Tumors

The presence of cytoplasmic sialyl glycoproteins is a conspicuous feature in chromophobe renal cell carcinoma (RCC). We compared the immunohistochemical expression of sialyl glycoproteins in chromophobe RCC with that in other types of renal tumors. Formalin-fixed, paraffin-embedded tissues of surgically resected renal tumors (chromophobe RCC, 14 cases [10 cases of classic type and 4 cases of eosinophilic variant]; oncocytoma, 7 cases; and clear cell RCC, 9 cases) and kidneys from immature infants (4 cases) were immunostained with antibodies against sialyl glycoproteins (anti-KL-6 and anti-sialyl MUC1 antibodies). Cytoplasmic expression of KL-6 and sialyl MUC1 was distinctive in the chromophobe RCC and renal oncocytoma cells, and in the intercalated cells in collecting duct epithelia. Apical-surface staining of these sialyl glycoproteins was predominantly observed in clear RCC, in the epithelia of the distal tubule and collecting duct, and in the neonatal renal proximal tubule, but not in those of the adult renal proximal tubule. The above-mentioned observations provide additional evidence for similar phenotypic profiles of chromophobe RCC and renal oncocytoma, and the intercalated cells in collecting ducts and the oncofetal expression of sialyl glycoproteins in clear cell RCC. KL-6 is a potential tumor marker for renal tumors.     

Sarcomatoid carcinoma with small cell carcinoma component of the urinary bladder: a case report with review of the literature

Sarcomatoid carcinoma of the urinary bladder is an uncommon neoplasm characterized histopathologically by the presence of malignant spindle cell and epithelial components. Albeit extremely rare, sarcomatoid carcinoma with small cell carcinoma has been reported. Herein, we describe an additional case of sarcomatoid carcinoma with small cell carcinoma and squamous cell carcinoma of the urinary bladder and review the clinicopathological features of this type of tumor. An 82-year-old Japanese male presented with hematuria. Computed tomography demonstrated a large tumor in the urinary bladder. Histopathological study of the resected urinary bladder tumor showed that approximately 80% of the tumor was comprised of small cell carcinoma, and the remaining components were spindle cell proliferation (approximately 15%) and squamous cell carcinoma (5%). Both the spindle cell and squamous cell carcinoma components were intermingled with nests of the small cell carcinoma. This is the fifth documented case of sarcomatoid carcinoma with small cell carcinoma of the urinary bladder. Our review of the clinicopathological features of this type of tumor revealed that: i) elderly males are mainly affected, ii) the most common chief complaint is hematuria, iii) the epithelial component may include urothelial carcinoma, adenocarcinoma, and/or squamous cell carcinoma, and iv) the sarcomatous component is composed of spindle cell proliferation. The histogenesis of this type of tumor remains a matter of controversy. However, recent molecular analyses demonstrated a monoclonal origin of both components. This theory can account for the various types of carcinomatous components in this tumor as seen in the present case.     

Decreased expression of mucin 18 is associated with unfavorable postoperative prognosis in patients with clear cell renal cell carcinoma

Background: MUC18 is correlated with tumor progression and metastasis in types of malignancy. But the role of MUC18 in clear cell renal cell carcinoma remains unclear. In this study, we aimed to investigate the expression of MUC18 and its correlation with clinical outcomes in clear cell renal cell carcinoma. Patients and Methods: Immunohistochemical staining was performed in samples from 288 patients with clear cell renal cell carcinoma. We used Kaplan-Meier method and Cox proportional hazard models to value the association between MUC18 expression and clinical outcome. Nomogram was constructed to predict overall survival at 5 and 8 years after nephrectomy. Results: MUC18 expression was significantly decreased in tumor compared to non-tumor tissue (P<0.001). Lower MUC18 expression in tumor predicted a shorter survival time (P=0.007). By multivariate cox analysis, MUC18 was defined as an independent prognostic factor (P=0.006). The nomogram performed better in predicting 5- and 8-year overall survival than the TNM stage alone in clear cell renal cell carcinoma. Conclusion: MUC18 is an independent prognostic factor for clear cell renal cell carcinoma and could be incorporated with the other parameters to predict 5- and 8-year overall survival for clear cell renal cell carcinoma patients.     

Fine-needle aspiration cytology of sarcomatoid renal cell carcinoma: A morphologic and immunocytochemical study of 15 cases

Sarcomatoid renal cell carcinoma (SRCC), which accounts for 5% of all renal cell carcinomas (RCC), has a worse prognosis than conventional nonsarcomatoid RCC. making accurate diagnosis important. This study reports on the morphologic and immunocytochemical features of 15 cases of SRCC (9 primary tumors and 6 metastases) diagnosed by fine-needle aspiration (FNA) biopsy. All but three cases showed a dimorphic cell population consisting of varying proportions of a high-grade epithelial component, either clear or granular-cell type and a spindle cell (sarcomatoid) component, of either fibrosarcomatous, malignant fibrous histiocytoma (MFH), or unclassified types. The sarcomatoid component in the biphasic and monophasic tumors stained positively for cytokeratin in 12 of 14 (85%) cases, for vimentin in 10 of 11 (91 %) cases, and for muscle-specific action in 4 of 11 (36%) cases. Of note, the three cases that demonstrated a purely sarcomatoid morphology stained positively for cytokeratin. Unlike in studies performed on surgically resected specimens, neither the proportion of the sarcomatoid component nor the presence of necrosis had prognostic significance, the discrepancy most likely being related to the sampling. We conclude that SRCC, both primary and metastatic, can be accurately diagnosed by FNA when cytologic features are evaluated in conjunction with immunocytochemical findings.     

Sarcomatoid collecting duct carcinoma of kidney diagnosed with urine and renal pelvic lavage cytology

A case of sarcomatoid collecting duct carcinoma (CDC) of kidney is presented, in which the diagnosis was made cytologically with voided urine and renal pelvis lavage. Cytology of hemorrhagic voided urine revealed highly atypical adenocarcinoma cells with reminiscent ductal structure, which suggested CDC as the most likely diagnosis. Computed tomography and magnetic resonance imaging demonstrated a left renal tumor, and selective lavage of left renal pelvis yielded spindle‐shaped, highly atypical cells that indicated sarcomatoid carcinoma. The diagnosis of renal cancer with urine cytology is challenging because of small number of tumor cells in the urine, which are often associated with degeneration. As the urinary cytologic findings of sarcomatoid CDC have not been reported, the characteristic cytologic findings of sarcomatoid CDC are described in detail, and the differential diagnoses with diagnostic pitfalls were discussed. Diagn. Cytopathol. 2010;38:603–606. 2009 Wiley‐Liss, Inc.     

Sarcomatoid carcinoma of the renal pelvis: a case report

A case of sarcomatoid carcinoma of the renal pelvis is reported. A 72-year-old male was admitted with a chief complaint of right flank pain. Clinical imaging studies revealed marked dilation of the right renal pelvis caused by a tumor at the pyeloureteric region. Right nephrectomy was performed in June 1999. The 8.4 x 6.5 cm tumor was grossly polypoid in appearance and protruded into the renal pelvis. Histologically, sarcomatoid spindle cells predominated over the carcinomatous component (mainly transitional cell carcinoma, partly associated with squamous cell and adenocarcinoma components). Osteoclast-like CD68-positive multinucleated giant cells were scattered. The sarcomatoid component was immunoreactive for both cytokeratin and vimentin. Sarcomatoid cells negative for cytokeratin were also noted. In both the sarcomatoid and carcinomatous components, nuclear overexpression of p53 oncoprotein was confirmed. The histogenesis of sarcomatoid carcinoma of the renal pelvis is discussed.     

乳腺肉瘤样癌

观察乳腺肉瘤样癌的病理形态学特点,分型,并分析其与某些肿瘤的鉴别诊断。方法１５３８例乳腺恶性肿瘤中１５例（０．９８％）诊断为乳腺肉瘤样癌,行ＡＥ１／ＡＥ３、上皮膜抗原（ＥＭＡ）、波形蛋白、Ｓ－１００蛋白、肌动蛋白、雌激素受体（ＥＲ）和孕激素受体（ＰＲ）ＳＰ法免疫组织化学染色。另有６例是外院会诊病例,共２１例。结果按其肉瘤样成分的特点分为４个形态学类型：（１）多形肉瘤型：肉瘤样成分为多形肉瘤样。（２     

Chromophobe renal cell carcinoma with neuroendocrine differentiation

Chromophobe renal cell carcinoma was described by Thoenes et al. in 1986, and associations with carcinoma of collecting ducts, conventional renal cell carcinoma and sarcomatoid renal cell carcinoma have been described. We report a case of chromophobe renal cell carcinoma which showed neuroendocrine differentiation. This is the first known case to be clearly identified as such. The patient was a 56‐year‐old man with constant right flank pain and hematuria; CT scan revealed an 8.5 cm non‐homogeneous mass involving the right kidney. Right radical nephrectomy was performed. The tumor showed a mixture of classical and eosinophilic patterns of chromophobe cell carcinoma. Additionally, it showed insular, glandular and rosetoid‐like formations embedded in a dense eosinophilic hyaline stroma. The cells were cuboid or cylindrical with well‐defined boundaries, finely stippled chromatin and a small nucleolus. The appearance of the cytoplasm varied from faintly eosinophilic to coarsely granular eosinophilic. Immunohistochemically, the neuroendocrine areas were reactive for C‐kit, epithelial membrane antigen, cytokeratin, cytokeratin 7, chromogranin A, neuron‐specific enolase, CD56 and S‐100 protein. Our case represents a typical chromophobe carcinoma with neuroendocrine differentiation. Additionally, the immunohistochemical profile in both types of lesion suggests a common origin from renal tubular cells.