Intrarenal neuroblastoma diagnosed by fine-needle aspiration: a report of two cases

Desmoplastic Small Round Cell Tumor of the Kidney: Report of a Case, Literature Review, and Comprehensive Discussion of the Distinctive Morphologic, Immunohistochemical, and Molecular Features in the Differential Diagnosis of Small Round Cell Tumors Affecting the Kidney

Desmoplastic small round cell tumor (DSRCT) is a rare, highly aggressive neoplasm typically presenting with widespread involvement of the abdominopelvic peritoneum of adolescent males, usually without organ-based primary. Although it is believed to originate from the serous (mainly peritoneal) membranes, intracranial, sinonasal, intraosseous, and other soft tissue sites are also documented. A chromosomal translocation t(11:22)(p13;q12) signature that fuses EWSR1 and WT1 genes results in the production of a chimeric protein with transcriptional regulatory activity that drives oncogenesis. Integration of clinical, morphologic, immunohistochemical, and genetic data is necessary to arrive at the correct diagnosis, especially when the tumor arises in an atypical site. A 15-year-old male presented with hematuria and was found to have a large renal tumor associated with adrenal, liver, lung, and bone metastases. Histopathologic and immunophenotypic features were distinctive for DSRCT. This diagnosis was confirmed by means of fluorescence in situ hybridization and cytogenetic analysis, which documented the pathognomonic t(11;22) translocation, and by reverse transcription polymerase chain reaction on snap-frozen tissue, which revealed the EWSR1/WT1-specific chimeric transcript. Despite high-dose chemotherapy and radiation therapy targeted to a single T11 vertebral metastasis, the disease progressed, and the patient died 4 years after the diagnosis. A search of electronic databases for DSRCT yielded 16 cases of well-documented renal primaries out of around 1570 cases from all sites gathered from the global literature. Desmoplastic small round blue cell tumor and other primary renal tumors considered in the differential diagnosis with DSRCT are discussed.

Diagnosis of pediatric neuroblastoma by urine cytology: A case report

Neuroblastomas are embryonal tumors arising from the neuronal crest cells of the synaptic nervous system. Findings from aspiration cytology have been reported, but there have been no reports of urine cytology findings. Here, we report a case of pediatric neuroblastoma characterized by urine cytology. A 2-year-old boy presented with abdominal pain, nausea, and loss of appetite. Computed tomography revealed a large tumor in the left suprarenal region with massive infiltration into the kidney. Urinary cytology showed highly cellular clusters composed of small, round, atypical cells with little cytoplasm and high nuclear/cytoplasmic ratio; nuclear molding was also noted in some places. Immunocytochemical staining was positive for synaptophysin and chromogranin A, and neuroblastoma was suggested by urine cytology. A biopsy of the left adrenal tumor later confirmed a diagnosis of poorly differentiated neuroblastoma. Urine cytology may be useful for rapid diagnosis and management of similar cases.

Surgical resection and post-operative radiotherapy in an adult renal neuroblastoma patient with multiple bone and joint metastases: A case report

Renal neuroblastoma is uncommon, particularly in adults, with only a few cases having been reported in studies published in the English language. The incidence is only 0.12 cases/1 million individuals in those aged >20 years. Studies of the pathogenesis, biological characteristics, treatment and prognosis of renal neuroblastoma are limited due to this low incidence. The present study reports the case of a 22-year-old adult female who was diagnosed with a left renal neuroblastoma by computed tomography (CT), bone scan and pathological examination. The patient underwent a left nephroureterectomy, ipsilateral lymph node dissection and post-operative radiotherapy, prior to discharge 60 days after admittance. At the nine-month follow-up examination, the patient showed no evidence of recurrence, progression or metastatic disease on the CT scans of the chest, abdomen and pelvis. Renal neuroblastoma is extremely uncommon in adults. The diagnosis and treatment of renal neuroblastoma is complicated by the overall low incidence, lack of specific treatment guidelines, advanced disease state due to late presentation, and its associated co-morbidities. Further study of the pathogenesis, biological and clinical characteristics, and treatment of renal neuroblastoma is required to provide an optimal treatment for patients and to improve the patient's quality of life.

Renal cell carcinoma with an Xp11.2 translocation in a 16-year-old girl: A case report with cytological features

We report a case of a 16-year-old girl with a left renal tumor discovered by her family practitioner. On physical examination the patient had a painless abdominal mass, located in the upper medium portion of the abdomen on the left side with a voussure of the abdominal wall. Ultrasound and abdominal pelvic CAT scan revealed a large heterogeneous mass with calcifications in the inferior portion of the left kidney. We made touch-imprint cytological preparations of the biopsy fragments, obtained under ultrasound guidance. Cytological analysis revealed highly cellular smears with malignant cells arranged in large clusters or rarely isolated, sometimes surrounding hyaline nodules with numerous psammoma bodies. After May-Grünwald-Giemsa staining, cells displayed moderately irregular nuclei with an abundant and pale basophilic cytoplasm with well-defined borders and a finely granular texture. The diagnosis of a special type of renal cell carcinoma was suspected, and was then confirmed after examination of the biopsy sample and the corresponding surgical specimen. The histomorphologic features were those of a renal cell carcinoma associated with an Xp11.2 translocation. Immunohistochemistry revealed this translocation by showing nuclear positivity in tumor cells for an antibody raised against the TFE3 protein. The clinical outcome was marked several months later by metastases in lymph nodes, bone, lung, and adrenal gland as well as a local recurrence.

Cytomorphology and morphometry of small round-cell tumors in the region of the kidney

Small round-cell tumors (SRCTs), with malignant cell components measuring 10 m or less in diameter with scanty cytoplasm in alcohol-fixed smears, pose a diagnostic challenge at fine-needle aspiration cytology (FNAC), especially when they are situated in and around the kidney and need facilities such as electron microscopy, immunohistochemistry, tissue culture, and cytogenetics for their subtyping. A precise cytodiagnosis of SRCTs is important because a definite diagnosis is mandatory in preoperative diagnostic workup for presurgical chemotherapy in these cases. With this view in mind, an attempt has been made to diagnose SRCTs in the region of the kidney based on cytomorphology and morphometry alone so as to facilitate its diagnosis in a simple cytology laboratory of a developing country where facilities for auxiliary techniques are not easily available. Of 2,028 abdominal aspirates in a 12-yr period, 36 SRCTs were diagnosed in the region of the kidney by correlating with histology, radiology, and clinical features. The smears were studied for cellularity, morphology, pattern of cell arrangement, and smear background and morphometrically analyzed using an ocular micrometer. An aspirate with preponderant malignant round cells that were larger or double the size of red blood cells in air-dried smears or measured less than 10 micro in diameter in alcohol-fixed smears was considered as a small blue-cell tumor. Twenty-one were diagnosed as Wilms' tumor (WT), 10 were diagnosed as neuroblastoma (NB), 3 were ganglioneuroblastoma (GNB), 1 was a cellular congenital mesoblastic nephroma (CMN), and 1 was an adrenocortical carcinoma (ACC). Cell clusters with neuropil and cytoplasmic processes were diagnostic of NB, ganglion cells of GNB, and blastema with tubular differentiation in WT. Aspirates from CMN and ACC were considered as simulators/mimickers of SRCT because they had superficial resemblance to SRCT and their differentiating cytomorphological features observed at histology were too subtle to be noted at cytology. The latter were appreciated only on retrospective analysis after histological confirmation.Thus, morphometry in correlation with cytology, clinical history, physical findings, and radiological data is helpful in guided FNA for a definite diagnosis of SRCT in the region of the kidney. One needs to keep in mind the mimickers of small round-cell lesions at this anatomic site.

Cytopathology of uncommon malignant renal neoplasms in the pediatric age group

Malignant renal neoplasms are common solid tumors in pediatric oncology practice. These include the common Wilms' tumor/nephroblastoma and the uncommon neoplasms such as clear-cell sarcoma of the kidney (CCSK), rhabdoid tumor, renal-cell carcinoma, and others. The aim of this study was to describe in detail the cytopathological features of the histopathologically proven uncommon pediatric renal tumors. Aspirates from Wilms' tumor, which are mesenchyme predominant, show clusters of spindle cells associated with the matrix material. Evidence of rhabdomyoblastic differentiation may be present. CCSK, classic subtype, is characterized by round to oval cells arranged perivascularly and also in sheets and clusters intimately associated with a metachromatic matrix mucopolysaccharide material better appreciated in May-Grunwald-Giemsa (MGG)-stained smears. The cells also have more abundant cytoplasm and may show nuclear grooves. Spindle-cell pattern of CCSK is difficult to diagnose on aspiration cytology. Renal-cell carcinoma of childhood shows similar cytological features as its adult counterpart. Rhabdoid tumor of the kidney is characterized by a monomorphic population of cells with abundant cytoplasm, eccentric nuclei with prominent nucleoli. Intrarenal yolk sac tumor is a rare neoplasm and shows severely pleomorphic cells on aspiration. Awareness of these entities is important for the practicing cytopathologist. Further, non-Wilms' renal malignant neoplasms must be distinguished from the common Wilms' tumor so that appropriate chemotherapy protocols may be instituted in cases where the tumor is in an advanced stage of malignancy.

Ectopic neural and neuroendocrine neoplasms

Although neural and neuroendocrine tissues are distributed virtually ubiquitously throughout the body, the occurrence of selected neoplasms related to those lineages is extremely uncommon in some topographic sites. This review considers the clinicopathologic characteristics of heterotopic pituitary adenomas; neuroendocrine carcinomas in non-organ-based locations; ectopic (extraneuraxial) meningiomas and gliomas; visceral neuroblastic neoplasms and primitive neuroectodermal tumors; and paragangliomas arising outside the sympathoadrenal neural network. Practical approaches to differential diagnosis are emphasized.