1/126. Clear cell sarcoma of soft parts: report of a case primary in the kidney with cytogenetic confirmation.Clear cell sarcoma of soft parts (CCSSP), also known as malignant melanoma of soft parts, is an aggressive tumor that usually presents in soft tissue and very rarely in small bowel. We report a case arising in the kidney of a 20-year-old man which was difficult to distinguish from Wilms' tumor. The tumor metastasized to the liver and lungs, and the patient died of disseminated disease 5 years after his initial presentation. Both the primary and metastatic tumors were composed predominantly of spindle cells with occasional more epithelioid areas that were inconsistently arranged in nests. In both primary and metastatic sites, the tumor surrounded and entrapped normal epithelial elements, mimicking the biphasic appearance of Wilms' tumor. The tumor cells, however, were positive for S-100 protein and HMB45 and negative for keratin and CD99, and cytogenetic analysis revealed a clonal abnormality, translocation t(12;22)(q13;q12), characteristic of CCSSP. This result was verified by fluorescence in situ hybridization on paraffin-embedded tissue, which demonstrated EWS gene-region rearrangement. CCSSP joins a growing list of tumors that typically arise in soft tissue (PNET, solitary fibrous tumor, and infantile/congenital fibrosarcoma), but can also present in the kidney and may be confused with primary renal tumors. awareness of this possibility and the use of ancillary studies. including immunohistochemistry, cytogenetic analysis, and fluorescence in situ hybridization, are important for accurate diagnosis.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
2/126. Metanephric adenofibroma: report of a case and review of the literature.The recent recognition of a variety of pediatric renal tumors of different biologic behavior places an ever-increasing demand on the surgical pathologist for an accurate diagnosis. Although metanephric adenofibroma is one of the rarest benign renal tumors, the clinical importance of correctly diagnosing it cannot be overemphasized because it can potentially be mistaken as Wilms' tumor. We describe the clinical, radiologic, and pathologic features of a case of metanephric adenofibroma and discuss its differential diagnosis. The neoplasm was composed of two discrete components: a major fibroblastic element and a minor immature epithelial element. The latter formed a small nodule beneath the renal capsule, which could barely be detected by magnetic resonance imaging. This subcapsular nodule, however, was slightly soft and tan and was distinctly different from the white, whorled cut surface of the main tumor. It was formed by closely packed small immature epithelial cells in a slightly edematous background, which was histologically identical to metanephric adenoma and closely resembled epithelial Wilms' tumor. Unlike Wilms' tumor, however, the epithelial cells were very bland with no mitoses. The main bulk of the tumor was formed by spindle fibroblastic cells that were cytologically similar to the spindle cells in congenital mesoblastic nephroma. The tumor, however, was well demarcated without the irregular infiltrating edges of congenital mesoblastic nephroma. In contrast to the randomly distributed epithelial element throughout the stromal component in previous reported cases of metanephric adenofibroma, our finding of the exceedingly small and discrete epithelial component expands the known histologic spectrum of the disease. In addition, the presence of such minute epithelial nodule underscores the importance of diligent pathologic examination and careful sampling of tissue for histologic examination.- - - - - - - - - - ranking = 1.2585536278535keywords = spindle cell, spindle (Clic here for more details about this article) |
3/126. Mesoblastic nephroma in adulthood: a case report.BACKGROUND: Mesoblastic nephroma is an uncommon renal tumor of infancy and rarely occurs in adults. We report an adult case of mesoblastic nephroma. methods: A 50-year-old woman was found incidentally to have a right renal mass by abdominal ultrasonography. Computed tomography and magnetic resonance imaging revealed a heterogeneous tumor and angiography showed a mixture of hypervascularity and hypovascularity. Right radical nephrectomy was performed. RESULTS: The tumor was an encapsulated yellowish solid mass. Microscopically, the tumor was composed of spindle cell proliferation. Atypia and mitoses were not identified. Among the tumor cells, there were tubular arranged epithelial elements. CONCLUSION: The patient was free of recurrence 14 months postoperatively. Mesoblastic nephroma is classified as a benign tumor but recurrence and malignant formation of this tumor have been reported so regular postoperative follow up is required.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
4/126. Clear cell sarcoma of kidney in an adolescent and in young adults: a report of four cases with ultrastructural, immunohistochemical, and dna flow cytometric analysis.Clear cell sarcoma of the kidney is a distinct, highly malignant pediatric neoplasm. Its occurrence in adults is extremely rare and the subject of isolated case reports. We present a series of four cases (three males and one female) identified in an adolescent and in young adults (16, 18, 20, and 25 years) with flank mass (three cases), hematuria (two cases), flank pain (two cases), and hypertension (one case). Three patients had stage III disease and one had stage I disease (National Wilms' Tumor Study staging system). All tumors had predominantly or exclusively the classic histology of a monotonous proliferation of uniform small round cells with evenly distributed fine chromatin, although focal microcyst formation (two cases) and spindled architecture (one case) (variant patterns) were also noted. Therapy in all cases consisted of surgery and chemotherapy with or without radiation. Follow-up data (29-202 months) showed distant metastases in all four cases, including the lung (four cases), bone (two cases), and the liver (two cases). Three patients died of disease at 29, 59, and 63 months (mean, 50.3 months), and one patient is alive with no evidence of disease at 202 months. Ultrastructural features included scattered primitive junctions, short and irregular cytoplasmic extensions, and scant to a moderate amount of mitochondria. Immunohistochemical study (three cases) showed immunoreactivity with vimentin (two cases) and no reaction with cytokeratin, epithelial membrane antigen, S-100 protein, or desmin. Flow cytometric analysis showed diploid dna content in three primary tumors and tetraploidy in one metastatic tumor. The proliferative activity (S-phase fraction) was low to intermediate (mean, 9.8%). Our data suggest that clear cell sarcoma of the kidney in the young adult age group resembles its pediatric counterpart in ultrastructural and immunohistochemical characteristics, proclivity for skeletal and visceral metastasis, dna diploid status with relatively low S-phase, and aggressive clinical course. Clear cell sarcoma of the kidney in adult patients, although rare, must be differentiated from sarcomatoid carcinoma, sarcomas, and round cell tumors because of its unique characteristics in comparison to other renal neoplasms.- - - - - - - - - - ranking = 0.25855362785353keywords = spindle (Clic here for more details about this article) |
5/126. Sarcomatoid renal cell carcinoma with scant carcinomatous components.A 30-year-old male underwent radical nephrectomy for a right renal tumor 15 cm in diameter. On microscopic examination of initial 17 sections, the tumor consisted of pleomorphic giant cells and spindle neoplastic cells. There was no carcinomatous component. Immunohistochemically, the neoplastic cells were negative for keratin and epithelial membrane antigen but positive for vimentin. The giant cells were also scatteringly, weakly positive for myoglobin. At that time a diagnosis of rhabdomyosarcoma of the kidney was made. However, further microscopic examination of another eight sections revealed small areas of clear cell-type renal cell carcinoma (RCC) which transited to sarcomatous components and led to a diagnosis of sarcomatoid RCC. The patient underwent three cycles of adjuvant chemotherapy. He has been free of the disease for 14 months after nephrectomy.- - - - - - - - - - ranking = 0.25855362785353keywords = spindle (Clic here for more details about this article) |
6/126. 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.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
7/126. Aspiration cytology of mesoblastic nephroma in an adult: diagnostic dilemma.A case of adult mesoblastic nephroma (MN) was erroneously interpreted as a benign mesenchymal tumor on fine-needle aspiration (FNA) cytology. MN is a rare tumor in infants and is extremely uncommon in adults. A 50-yr-old female presented with a renal lump with the clinicoradiological possibility of renal-cell carcinoma. Giemsa-stained smears were highly cellular and showed cohesive interlacing fragments of spindle cells embedded in abundant pink fibrillary stromal matrix. Epithelial component was seen in the form of tubules. Pleomorphism, mitosis, and necrosis were absent. Cytologic features in both adult and infantile MN are similar, but in an adult can be mistaken for benign or malignant mesenchymal tumor and the sarcomatoid variant of renal-cell carcinoma. FNA in such a rare yet cytomorphologically characteristic lesion can be helpful in guiding the management. awareness on the part of both the clinician and the cytopathologist is necessary to resolve the diagnostic dilemma.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
8/126. Inflammatory pseudotumor of the renal pelvis. A report of 2 cases with clinicopathologic and immunohistochemical study.We describe 2 cases of inflammatory pseudotumor of the renal pelvis. Case 1, the male patient, was 37 years old, and case 2, the female patient, was 54 years old. Both patients presented with macroscopic hematuria and flank pain. Computed tomographic (CT) scan and ureterocystoscopy revealed in case 1 a mass in the left renal pelvis and the calyces. In case 2, urography showed a lacuna of the renal pelvis, and CT scan showed an irregular thickening of the renal pelvis. In both cases, the preoperative clinical diagnosis was urothelial carcinoma, and both patients underwent nephrectomy. Microscopic examination revealed in case 1 a tumor of the renal pelvis composed of spindle cells with eosinophilic cytoplasm in a myxoid and vascular stroma with abundant inflammatory infiltrate. In case 2, the tumor was composed of densely basophilic spindle cells in a fascicular pattern intermingled with lymphocytes and plasma cells and involving the lamina propria of the renal pelvis. The spindle cells reacted strongly with antibody to vimentin and focally with antibodies to smooth muscle actin and muscle-specific actin. In the urogenital tract inflammatory pseudotumor involves preferentially the urinary bladder. Rare cases have been reported in the kidney. The 2 cases presented here are unusual due to the location in the renal pelvis, mimicking urothelial carcinoma.- - - - - - - - - - ranking = 3keywords = spindle cell, spindle (Clic here for more details about this article) |
9/126. Primary synovial sarcoma of the kidney.The authors present two cases of primary synovial sarcoma of the kidney. Both patients had a mass in the upper part of the right kidney without any primary extrarenal neoplastic lesions. Grossly, the tumors were soft to rubbery masses measuring 5.5 cm and 5 cm in diameter, respectively. Histologically, both tumors were poorly differentiated synovial sarcoma. The lesions exhibited a hypercellular solid or lobular growth of round, oval, or short spindle cells in variably solid sheets, in intersecting fascicles, or in a haphazard fashion. Areas of solid aggregation or fascicles of the tumor cells alternating with hypocellular myxoid tissues, together with areas displaying a prominent hemangiopericytoma-like pattern, were found. Immunohistochemically, vimentin was diffusely positive and a few tumor cells were positive for cytokeratin, epithelial membrane antigen, and neurofilament. The tumor cells were negative for S- 100 protein, CD34, smooth muscle actin, and desmin, whereas CD56 and CD99 were positive. In both cases, reverse transcription-polymerase chain reaction using ribonucleic acid extracted from formalin-fixed, paraffin-embedded tissues detected SYT-SSX2 fusion gene transcripts, which are characteristic molecular findings of synovial sarcoma. One patient died 10 months after diagnosis. These tumors are unique cases of primary synovial sarcoma of the kidney confirmed by molecular study.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
10/126. Solitary fibrous tumour of the kidney.Solitary fibrous tumours are relatively rare neoplasms initially described in the pleura. Such lesions are now reported in many extrathoracic sites. To our knowledge, only 8 cases have been reported in the kidney. All these cases were benign. We report a patient with a solitary fibrous tumour of the kidney with infiltration of the wall of the renal vein. Microscopic examination showed proliferation of spindle cells with a prominent vascular haemangiopericytoma-like pattern. Hypercellular areas were admixed with hyalinized collagenous zones. The neoplastic cells stained for vimentin and CD34. CD31 was negative. Biologically, we did not find any arguments for malignancy: the flow cytometric study showed diploid histograms, and immunostaining for p53 was negative.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
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