Fine-needle aspiration cytology of clear-cell sarcoma of the kidney: study of eight cases

The largest series, to date, of fine-needle aspiration cytology (FNAC) findings in clear-cell sarcoma of the kidney (CCSK) is presented. All fine-needle aspirates of pediatric renal masses over a 17-yr period were reviewed. Eight out of 119 aspirates from late-stage childhood renal tumors (6.72%) were found to be CCSK. Ten aspirates from these eight patients and histopathological confirmation in six patients were available. Aspirates were cellular with three cell types: cord cells, septal cells, and small pyknotic cells. Cord cells, seen in all aspirates, were large polygonal cells with abundant eccentrically placed wispy cytoplasm, round to oval nuclei, and fine dusty chromatin. Occasional bare nuclei and frequent nuclear grooves were also seen. Small pyknotic cells were a degenerative change identified in 9 out of 10 aspirates. Stromal fragments with branching vascular cores were seen in 8 out of 10 aspirates, 6 of which had myxoid substance surrounding the vessel. Septal cells were spindle shaped and usually embedded in the stromal fragments. On the basis of cytology and histology, cases were classified into classical CCSK (5 cases), spindle-cell CCSK (1 case), and anaplastic CCSK (2 cases). Classical CCSK showed mostly cord cells with few stromal fragments. Spindle-cell CCSK showed preponderance of myxoid stromal fragments and septal cells. Anaplastic CCSK showed bizarre pleomorphic nuclei, coarse chromatin, and atypical mitosis. Cytology of CCSK is a spectrum with varying proportions of cord cells, septal cells, and mucopolysaccharide substance. Anaplastic CCSK is liable to misdiagnosis as Wilms tumor (WT) with unfavourable histology. Presence of eccentric cytoplasm in cord cells and nuclear grooves are the key to differentiation from Wilms tumor, including anaplastic variants.     

Intraoperative imprint cytology of ovarian transitional cell (Brenner) tumors: A retrospective study

Literature on fine‐needle aspiration of ovarian transitional cell tumor or Brenner tumors is sparse and mostly confined to isolated case reports of metastatic transitional cell tumors. We undertook a retrospective study of intraoperative imprint cytology of ovarian transitional cell tumors to better define the cytologic features of this uncommon ovarian tumor. Between 2005 and 2012, a total of 19 ovarian transitional cell tumors were recorded in our surgical pathology files, 10 of which had concomitant imprint cytologic material available for review. The 10 patients included in this study ranged in age between 43 and 73 years (mean age: 54 years). Nine neoplasms were histologically benign and one was borderline. Nine cases had satisfactory cytologic material for review. The cytologic features can be summarized as follows: the eight benign tumors showed abundant naked nuclei in the background, small and large clusters of tumor cells, abundant cytoplasm, smooth nuclear membranes, and lack of nuclear pleomorphism and mitoses. Single plasmacytoid cells with dense blue abundant cytoplasm, perinuclear vacuoles, nucleoli, microfollicle formation, nuclear grooves, binucleation/multinucleation, and extracellular eosinophilic material were some of the other features that were appreciated. The cytologic features of the one case of borderline transitional cell tumor were similar to those of the benign tumors except for the presence of rare mitoses, easily identifiable nuclear pleomorphism and irregular nuclear membranes. This study highlights some characteristic cytologic features of benign/borderline transitional cell tumors of the ovary which can be of help in recognizing this uncommon neoplasm. Diagn. Cytopathol. 2014;42:660–663. © 2014 Wiley Periodicals, Inc.     

Cytodifferentiated renal tumors occurring with Wilms' tumors of the opposite kidneys: report of two cases.

The most common differentiated renal tumor of early childhood is the congenital mesoblastic neophroma. Well-differentiated forms of Wilms' tumor may present a difficult differential diagnosis from these benign neoplasms. The cases of two patients found to have well-differentiated renal neoplasms after being treated for Wilms' tumor of the opposite kidneys are reported. The second neoplasms were composed of a benign-appearing stroma with mature skeletal muscle and completely lacked any embryonal, nephroblastic tissue. These benign-appearing neoplasms may be cytodifferentiated variants of Wilms' tumor. Though tumors of this type may have a malignant potential, there is evidence to indicate that they may be approached more conservatively than the usual nephroblastoma. In cases of bilateral Wilms' tumor, well-differentiated tumors might be treated by partial nephrectomy alone, with careful preservation of functional renal tissue.     

Preoperative diagnosis of clear cell sarcoma of the kidney by detection of BCOR internal tandem duplication in circulating tumor DNA

Clear cell sarcoma of the kidney (CCSK) is the second most common renal malignancy in children. The prognosis is poorer in CCSK than in Wilms’ tumor, and multimodal treatment including surgery, intensive chemotherapy, and radiation is required to improve the outcome for children with CCSK. Histological evaluation is required for the diagnosis. However, biopsies of tumors to obtain diagnostic specimens are not routinely performed because of the risk of spreading tumor cells during the procedure. Recently, internal tandem duplication (ITD) of BCOR has been recognized as a genetic hallmark of CCSK. We herein established a novel BCOR‐ITD‐specific polymerase chain reaction method with well‐designed primers, and then performed a liquid biopsy for cell‐free DNA (cfDNA) obtained from plasma of three children with nonmetastatic renal tumors (stage II) and from one control. BCOR‐ITD was positively detected in the cfDNA of two cases, both of which were later diagnosed as CCSK based on histological feature of the resected tumor specimen, while it was not detected for a normal control and a patient diagnosed with Wilms’ tumor. Our study is the first one of preoperative circulating tumor DNA assay in pediatric renal tumors. The liquid biopsy method enables less invasive, preoperative diagnosis of CCSK with no risk of tumor spillage, which can avoid iatrogenic upstaging.     

Intriguing Case: Primitive Pelvic Sarcoma Resembling Clear Cell Sarcoma of Kidney

Clear cell sarcoma of kidney (CCSK) is an aggressive childhood renal tumor of unknown histogenesis that has not been reported to occur outside the kidney. The article describes an extrarenal neoplasm arising in the pelvic soft tissues of a 13-year-old boy that was composed predominantly of uniform mesenchymal cells with optically clear cytoplasm supported by an arborizing network of small blood vessels, which was indistinguishable in appearance from CCSK. The electron microscopic findings, although nonspecific, were essentially identical to those of CCSK, with tumor cells displaying fine chromatin, electron-lucent cytoplasm, and intercellular collagen but no evidence of tissue-specific differentiation. Immunocytochemical studies showed positivity for vimentin but negative results for desmin, myoglobin, cytokeratin, epithelial membrane antigen, S-100 protein, neuron-specific enolase and factor VIII-related antigen. Tumor cells were also nonreactive with Ulex lectin. This unusual pelvic tumor and CCSK may both derive from primitive mesenchymal cells and may represent phenotypic but not necessarily histogenetic analogs.     

Clear cell sarcoma of the kidney. An immunohistochemical study

Three cases of clear cell sarcoma of the kidney (CCSK) and 5 cases of Wilms' tumor were investigated immunohistochemically to examine the expression of tissue-specific intermediate filaments (cytokeratin, vimentin, and desmin) and myoglobin. In CCSK, tumor cells were negative for cytokeratin, except for occasional tubular structures, and vimentin was demonstrated in only one case. In Wilms' tumor, epithelial components were positive for cytokeratin and stromal cells were positive for vimentin, while no staining was found in blastemal cells for either. Both desmin and myoglobin were negative in all tumor cells except for skeletal muscle cells in Wilms' tumor. In the current study, some neoplastic cells in CCSK were revealed to be of mesenchymal nature, but blastemal cells in Wilms' tumor were not.     

Intriguing Case: Primitive Pelvic Sarcoma Resembling Clear Cell Sarcoma of Kidney

Clear cell sarcoma of kidney (CCSK) is an aggressive childhood renal tumor of unknown histogenesis that has not been reported to occur outside the kidney. The article describes an extrarenal neoplasm arising in the pelvic soft tissues of a 13-year-old boy that was composed predominantly of uniform mesenchymal cells with optically clear cytoplasm supported by an arborizing network of small blood vessels, which was indistinguishable in appearance from CCSK. The electron microscopic findings, although nonspecific, were essentially identical to those of CCSK, with tumor cells displaying fine chromatin, electron-lucent cytoplasm, and intercellular collagen but no evidence of tissue-specific differentiation. Immunocytochemical studies showed positivity for vimentin but negative results for desmin, myoglobin, cytokeratin, epithelial membrane antigen, S-100 protein, neuron-specific enolase and factor VIII-related antigen. Tumor cells were also nonreactive with Ulex lectin. This unusual pelvic tumor and CCSK may both derive from primitive mesenchymal cells and may represent phenotypic but not necessarily histogenetic analogs.     

CLEAR CELL SARCOMA OF THE KIDNEY An Immunohistochemical Study

Three cases of clear cell sarcoma of the kidney (CCSK) and 5 cases of Wilms' tumor were investigated immunohistochemically to examine the expression of tissue-specific intermediate filaments (cytokeratin, vimentin, and desmin) and myoglobin. In CCSK, tumor cells were negative for cytokeratin, except for occasional tubular structures, and vimentin was demonstrated in only one case. In Wilms' tumor, epithelial components were positive for cytokeratin and stromal cells were positive for vimentin, while no staining was found in blastemal cells for either. Both desmin and myoglobin were negative in all tumor cells except for skeletal muscle cells in Wilms' tumor. In the current study, some neoplastic cells in CCSK were revealed to be of mesenchymal nature, but blastemal cells in Wilms' tumor were not.     

Primitive pelvic sarcoma resembling clear cell sarcoma of kidney.

Clear cell sarcoma of kidney (CCSK) is an aggressive childhood renal tumor of unknown histogenesis that has not been reported to occur outside the kidney. The article describes an extrarenal neoplasm arising in the pelvic soft tissues of a 13-year-old boy that was composed predominantly of uniform mesenchymal cells with optically clear cytoplasm supported by an arborizing network of small blood vessels, which was indistinguishable in appearance from CCSK. The electron microscopic findings, although nonspecific, were essentially identical to those of CCSK, with tumor cells displaying fine chromatin, electron-lucent cytoplasm, and intercellular collagen but no evidence of tissue-specific differentiation. Immunocytochemical studies showed positivity for vimentin but negative results for desmin, myoglobin, cytokeratin, epithelial membrane antigen, S-100 protein, neuron-specific enolase and factor VIII-related antigen. Tumor cells were also nonreactive with Ulex lectin. This unusual pelvic tumor and CCSK may both derive from primitive mesenchymal cells and may represent phenotypic but not necessarily histogenetic analogs.     

Fine-needle aspiration biopsy of clear-cell sarcoma of the kidney: light and electron microscopic features

Smears from seven fine-needle aspiration biopsies from three patients with clear-cell sarcoma of the kidney were reviewed, and the findings were correlated with corresponding histopathologic appearances. In two cases, the tumor cells were polygonal to spindle-shaped and were loosely arranged in a matrix of mucoid material. The histopathologic examination of the resected tumors in these cases revealed a classic pattern. In the third case, the aspiration smears revealed round to polygonal cells with moderate to abundant cytoplasm but without the mucoid matrix. The predominant histologic appearance of this tumor was an epithelioid trabecular pattern. Electron microscopic findings were similar to those described in published studies.     

肾透明细胞肉瘤的临床病理学研究

目的：探讨肾透明细胞肉瘤的临床病理,免疫组织化学,电镜特点和组织起源及预后,方法：对45例患儿（男31例,女14例,年龄3个月至12岁,平均3．2岁）肿瘤标本,用HE,免疫组织化学（LSAB法）和电镜技术进行观察。结果：45例患儿中,35例随访6－192个月,骨转移15例,,肺,肝等转移6例,8例复发,20例死亡。年龄和临床分期与存活率有关。典型的组织学形态为胞质浅染,核染色质细腻,核仁不清楚的片状瘤树枝状分布的纤维血管间质分隔,此外还可见粘液型,梭形细胞型,栅栏状型,上皮样型,硬化型,富于细胞型,囊肿型和血管扩张型等组织亚型结构,免疫组织化学;45例均表达波形蛋白,上皮膜抗原,细胞角蛋白,结蛋白,肌动蛋白,S－100蛋白,神经元特异性烯醇化酶,CD99,CD34和白细胞共抗原均为阴性,电镜下9例均显示瘤细胞细胞连接很原始,细胞器相对较少。结论：肾透明细胞肉瘤好发于儿童,具特殊的病理形态,可能起源于肾原始间质细胞,易发生骨;转移,死亡率高,为预后差的儿童肾肿瘤。     

Translocation 10;17 in clear cell sarcoma of the kidney. A first report

This is the first report of a t(10;17) as the unique cytogenetic finding in one case of a rare childhood tumor, clear cell sarcoma of the kidney (CCSK). This observation is discussed in relation to the cytogenetics of Wilms' tumors, of which CCSK is a variant.     

Extragonadal germ cell tumors: A fine-needle aspiration biopsy study

Germ cell tumors (GCT) are neoplasms that originate predominately in the ovary and testis. Tumors of germ cell origin only very uncommonly arise in extragonadal sites. We have diagnosed ten primary malignant extragonadal GCT arising in the mediastinum, retroperitoneum, liver, and sacrococcygeal region by fine-needle aspiration biopsy (FNAB). Patient ages ranged from 1 to 54 years; the majority were males. Our series included three seminomas, three yolk sac tumors (YST), one choriocarcinoma, one embryonal carcinoma, and two mixed, poorly differentiated GCT. in aspirates, seminomatous elements are dissociated with uniform mononucleate cells having large vesicular nuclei and prominent nucleoli. A tigroid background is produced with Diff-Quik—stained smears. YST yields cohesive clusters of cells with large nuclei, vacuolated cytoplasm, and extracellular hyaline matrix (spheres or hyaline globules). Giant multinucleate tumor cells are seen in choriocarcinoma. Embryonal carcinoma yields cellular smears of hyperchromatic cells with scant cytoplasm arranged predominantly in glandular or papillary formations. Ultrastructural (four cases) and immunocytochemical (seven cases) studies of aspirated material corroborated our cytologic interpretations. Aneuploid tumor cells were found by flow cytometry in aspirated material from a YST. Subsequent histologic examinations were performed on eight, and all were confirmatory. Although extragonadal GCT are relatively uncommon, they need to be considered in FNAB material from midline mass lesions. Ancillary studies were useful in confirming their diagnosis. © Wiley-Liss, Inc.     

Atypical granular cell tumor of the thyroid: cytomorphologic features on fine needle aspiration

Granular cell tumors are uncommon soft tissue neoplasms of nerve sheath origin, which are predominately benign and are characterized by abundant granular cytoplasm, uniform nuclei, and indistinct cell borders. Features of malignancy include spindle cell morphology, necrosis, prominent nucleoli, increased nuclear to cytoplasmic ratio, nuclear pleomorphism, and increased mitotic rate. Granular cell tumors are most common in the soft tissues of the head and neck, but have only been rarely described in the thyroid gland. Here we report a case of an atypical granular cell tumor of the thyroid seen on fine needle aspiration, which displayed focal atypical cells with spindle cell morphology, increased nuclear to cytoplasmic ratio, and prominent nucleoli. The differential diagnosis of such findings is also presented.     

Cellular mesoblastic nephroma in an infant: Report of the cytologic diagnosis of a rare paediatric renal tumor

Congenital mesoblastic nephroma is a rare pediatric tumor with a favorable clinical outcome. Cytological features of this uncommon tumor and diagnostic difficulties with other commoner pediatric renal neoplasms have been inadequately discussed in the available literature. We describe the case of a 1‐year‐old girl who presented with a right renal mass. Fine‐needle aspiration smears consisted of a few cellular clusters of spindle cells with mitotic activity and mild nuclear pleomorphism. No blastema was identified. A cytologic impression of mesoblastic nephroma was rendered, which was confirmed on histopathological examination of the right nephrectomy specimen as a cellular mesoblastic nephroma. Cytologic diagnosis of mesoblastic nephroma has important prognostic and therapeutic implications. The cytopathologist should carefully evaluate smears from such patients and attempt to differentiate mesoblastic nephroma from Wilms' tumor and clear cell sarcoma. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.     

Malignant rhabdoid tumor of the kidney--a case report.

Malignant rhabdoid tumor is a distinct renal tumor in children. It had been regarded as a rhabdomyosarcomatoid variant of Wilms' tumor, but it is now thought as a separate entity. We report a case of malignant rhabdoid tumor of the kidney in a 26-month-old girl who presented with a left abdominal mass. Grossly, a large mass in the lower pole of the left kidney was well encapsulated and measured 4 x 4 x 3.5cm. On cross section, it was soft and yellowish white and showed multifocal necroses. The mass was mainly located in the medial medullary portion and compressed the renal pelvis laterally. Microscopically, the tumor masses were hypercellular and anaplastic without definite blastematous elements. In larger portion, the tumor cells had abundant eosinophilic cytoplasm and hyaline globules. In addition to the classic "rhabdoid" feature, alveolar, sclerosing, and lymphomatous patterns were seen. Ultrastructurally, tumor cells with abundant cytoplasm contained tangles of intermediate filament corresponding to vimentin in immunostaining.     

Rare Pediatric Adrenocortical Carcinoma with Oncocytic Change: A Cytologic Dilemma

Pediatric adrenocortical carcinoma is extremely rare with a prevalence of 0.3 per million. Adrenocortical neoplasms in children usually present with one of the endocrine abnormalities. Adrenocortical neoplasms cannot be easily diagnosed on cytopathology; hence, the cytomorphological features posing diagnostic dilemmas are discussed in a pediatric patient presenting with palpable abdominal mass and virilization. Fine-needle aspiration smears were cellular showing cells in cohesive clusters adhering to central core of capillaries exhibiting an endocrine vascular pattern along with single cells and stripped nuclei. Cells were polygonal in shape and had abundant cytoplasm with well-defined borders and round eccentric nuclei with prominent nucleoli. Marked anisonucleosis was also noted. Few cells showed abundant granular cytoplasm resembling oncocytes. Many bizarre and multinucleated cells, few mitotic figures, and necrosis were also seen. Hematoxylin and eosin-stained sections of tumor biopsy suggested possibility of adrenocortical neoplasm. A panel of immunohistochemical markers were used to exclude possibility of renal cell carcinoma (RCC) and pheochromocytoma that showed vimentin (+), cytokeratin (−), inhibin-α (+), neuron-specific enolase (focally +), and chromogranin (−). The Ki67 index was 15%, and P53 was strongly positive. It is difficult to distinguish adrenocortical neoplasm, RCC, and pheochromocytoma on cytology because of overlapping features; hence, important cytological features which help in distinguishing between the three are discussed.     

Cytologic findings of acquired cystic disease-associated renal cell carcinoma: a report of two cases

Renal tumors may arise in the setting of end-stage renal cell disease. The risk is 100 times that of the normal population with an incidence ranging from 3-7%. The most common malignant tumor to arise in the setting of acquired cystic disease of the kidney is the acquired cystic disease-associated renal cell carcinoma (ACD-associated RCC). The cytomorphologic features of ACD-associated RCC, which has not been described previously, show moderately cellular specimens composed of clusters of cells with papillary configuration. The cells ranged from polygonal to columnar and contained abundant eosinophilic granular cytoplasm. The nuclei were round and centrally located, and the chromatin was finely granular with prominent central nucleoli that corresponded to Fuhrman's grade 3 nucleolar size. The main differential diagnosis is type 2 papillary renal cell carcinoma, from which it can be distinguished based on clinical findings only at this moment.