An ultrastructural and immunohistochemical evaluation of cytodifferentiation in neuroblastic tumors

Twenty-six cases of neurogenic tumors consisting of 2 ganglioneuromas (GN), 8 ganglioneuroblastomas (GNB), and 16 neuroblastomas (NB) were studied to evaluate their cytodifferentiation. Ultrastructurally, a moderate to large number of neuritic processes and high density neurosecretory granules (NSG) were found in all cases of GN and well-differentiated GNB, in two-thirds of poorly differentiated GNB, in about a half of rosette-fibrillary NB, and in no case of round-cell NB. All GN and GNB had tumor cells which were positive for both chromogranin and neurofilaments. Of the 16 cases of NB, 12 were positive for chromogranin, and 13 and 15 were positive for Mr 200,000 and 68,000 neurofilament polypeptides, respectively. However, both markers appeared mainly in tumor cells maturing toward neuroblasts. Electron microscopy was helpful for the diagnosis of undifferentiated NB in those cases immunohistochemically negative for chromogranin or neurofilaments. We conclude that ultrastructural and immunohistochemical examinations are useful for the morphologic assessment of the degree of maturation of neuroblastic tumors.     

Fine-needle aspiration of intra-abdominal desmoplastic small cell tumor

The cytologic features of four cases of histologically confirmed intra-abdominal desmoplastic small cell tumor (DSCT) that occurred in males between 18-27 yr of age are presented. Smears showed small cells with scant cytoplasm which were primarily arranged in loosely cohesive clusters. Nuclei were oval to round with evenly distributed, finely granular chromatin and inconspicuous nucleoli. As is typical of DSCT, the cells strongly expressed keratin and desmin in all cases. In the one case studied by electron microscopy, it was demonstrated that the cells were joined by small junctions and contained paranuclear aggregates of intermediate filaments. The absence of the characteristic desmoplastic stroma in DSCT aspirates and the nonspecific cytologic features of this small round-cell tumor (SRCT) made cytologic interpretation difficult. Cytopathologists should be aware of this entity so that DSCT is included in the differential diagnosis of SRCTs that occur in intra-abdominal sites. A panel of markers that includes keratin and desmin should be used to assist in the identification of DSCT.     

Fine-needle aspiration of adult small-round-cell tumors studied with flow cytometry

Immunophenotypic study is critical for the diagnosis of adult small-round-cell tumors (SRCTs). We describe three patients with Ewing's sarcoma/primitive neuroectodermal tumor (ES/PNET) and one patient with neuroblastoma in which flow cytometry immunophenotyping (FCI) on the fine-needle aspirate (FNA) and bone marrow aspirate (BMA) demonstrated an abnormal population of cells that were CD45(-) and CD16/CD56(+). Four patients with mean age of 30 years, three male and one female, clinically suspicious for a lymphoma or SRCT are described. FNA, BMA, and biopsy specimens were obtained for routine cytologic and histologic evaluation. Fresh tissue was studied by FCI. In all cases, the cytology smears showed small cells with round nuclei, slightly irregular nuclear membranes, fine chromatin, and scant cytoplasm. FCI showed CD16/56(+) and CD45(-) neoplastic cells in all cases. In one case, 76% of these cells were CD99(+). The diagnoses of ES/PNET were confirmed by immunohistochemical, ultrastructural, and cytogenetic studies. ES/PNET in FNA and BMA can be efficiently and rapidly diagnosed by combining cytologic examination with FCI using a panel including CD45, CD16/56, and CD99.     

Thyroid tumors: cytomorphology of medullary, clinically anaplastic, and miscellaneous thyroid neoplasms

Of 2,012 fine-needle aspirations (FNAs) of the thyroid performed between the years 1984 and 1988, detailed cytomorphologic analysis of 95 cases diagnosed as neoplastic on histology and/or cytology and those that received an equivocal cytodiagnosis are presented in this article. Discussed are medullary thyroid carcinomas (nine cases), clinically anaplastic thyroid tumors (CATT; eight cases), two cases of non-Hodgkin's lymphoma (NHL), and one primary leiomyosarcoma of the thyroid, for a total of 20 cases. Included in the category of CATT are all the thyroid tumors presenting clinically with an anaplastic growth pattern. The cytomorphology of these tumors varied, but the giant- and spindle-cell pattern was predominant. An accurate cytodiagnosis was possible, as per cytohistologic correlation, in seven cases, while in one case histological material was not available for study. Medullary carcinoma of the thyroid (MCT) showed a mixed spindle-cell and round-cell population in eight cases and an entirely spindle-cell population in one case. All cases of MCT were correctly diagnosed on cytology, and amyloid could be demonstrated in the cytologic smears in three cases. The cases of NHL and leiomyosarcoma could also be correctly interpreted on cytology.     

Intracellular acidic mucins and their identification in diagnostic cytology

Exfoliative, abrasive and aspiration cytology were increasingly relied upon for tissue diagnosis of tumours. The established histological stains for the differentiation of mucin and non-mucin-secreting tumours are not ideal for alcohol-fixed cytology smears and a more reliable cytological technique for the preservation and staining of intra-cellular acidic mucins using Alcohol Alcian Blue 8GX is presented.     

Diagnosis of retinoblastoma by fine-needle aspiration and aqueous cytology

This article reports the cytodiagnosis of three cases of retinoblastoma in children aged 1.5, 2.5, and 5 yr. Two of them were diagnosed by fine-needle aspiration cytology of the primary tumor and one by aqueous cytology. The tumor cells were usually round to oval, small and uniform, with scanty cytoplasm; they generally occurred in closely packed clusters of variable sizes. We discuss the differential diagnosis of retinoblastoma with other round-cell tumors of childhood involving the orbit.     

Fine-needle aspiration cytology and immunocytochemistry of soft-tissue tumors and osteo/chondrosarcomas of the head and neck

The purpose of the study was to present the clinical and cytological findings of 28 cases of malignant or borderline mesenchymal tumors of the head and neck, of which 22 originated from soft tissue and 6 were found in bone or cartilage. The basic procedures employed involved a cytologic review and subclassification of fine-needle aspiration (FNA) smears from the tumors, which were diagnosed as: pleomorphic sarcomas (5 poorly differentiated, 1 angiosarcoma, and 1 epithelioid sarcoma), spindle-cell sarcomas (2 leiomyosarcomas, 2 malignant mesenchymal tumors, and 1 malignant schwannoma), myxoid sarcomas (2 liposarcomas and 1 high-grade tumor), round-cell tumors (1 malignant histiocytic tumor and 1 chloroma), osteosarcomas (3), chondrosarcomas (3), and borderline tumors (2 pleomorphic lipoma, 1 myxolipoma, 1 cranial fasciitis, and 1 fibromatosis). Histological correlation and problems in subtyping on both cytologic and histological material are discussed. It is concluded that FNA cytology can be used with high accuracy to diagnose musculoskeletal tumors in rare sites such as the head and neck.     

Melanotic neuroectodermal tumor of infancy in the soft tissues of the arm: fine needle aspiration biopsy and histologic correlation-a case report

A case of melanotic neuroectodermal tumor of infancy (MNTI) presenting as a soft tissue mass in the right arm of a 6-mo female child is discussed. The mass was diagnosed by fine-needle aspiration biopsy (FNAB) and confirmed by histological examination. This communication emphasizes the characteristic cytology of MNTI and discusses its significance in the context of this tumor occurring in the soft tissues. The cytology smears were distinctive in showing a dual population of small, rounded, undifferentiated cells and larger melanin-containing epithelial-like cells. It is the identification of the latter cells in the smears which differentiates this tumor from other round cell tumors of infancy and helps in the correct diagnosis by FNAB.     

Fine-needle aspiration cytology of primitive neuroectodermal tumor of the urinary bladder: a case report

Primitive neuroectodermal tumors (PNETs) are malignant small round cell tumors, which exhibit a variable degree of neural differentiation. These tumors are usually found in the extraosseous soft tissue and rarely in bones. Occasional cases of PNETs of the urinary bladder have been reported on histopathology. However, to the best of our knowledge, none have been diagnosed on fine-needle aspiration cytology (FNAC). A patient presented to the out-patient department with complaints of a slowly progressive lump in the lower abdomen, which was diagnosed as PNET on FNAC. The smears showed a dispersed population and sheets of malignant small round cells with focal rosette formation and perivascular arrangement of tumor cells. Periodic acid-Schiff staining showed strong cytoplasmic positivity. Immunocytochemistry of the cytology smears also showed strong membrane positivity for CD99 (MIC-2), which was also confirmed on histopathological examination. PNET of the urinary bladder is a distinct entity, which can be diagnosed on FNAC and confirmed by immunohistochemistry. A diagnosis of PNET should be considered as a differential diagnosis in urinary bladder masses, especially in adolescents and young adults.     

Intranuclear cytoplasmic inclusions—An extremely unusual finding in embryonal rhabdomyosarcoma: Report of a case diagnosed by fine‐needle aspiration biopsy

Embryonal rhabdomyosarcoma (ERMS) is one of the commonest childhood tumors that usually presents as a small round cell tumor (SRCT). We report a case of an ERMS expressing frequent and prominent intranuclear cytoplasmic inclusions (INCIs). Our patient was a 3‐year‐old female child who presented with proptosis of the left eye with left sided cervical lymphadenopathy. Fine‐needle aspiration (FNA) smears from both the orbital lesion and the cervical lymph nodes were cellular with features of a small round cell tumor (SRCT). The most striking cytologic feature observed was the presence of frequent and highly prominent INCIs. Despite the diagnostic dilemma caused by this unusual finding, a differential diagnosis of peripheral neurectodermal tumor (PNET) /Ewing's sarcoma, neuroblastoma, and ERMS was considered. Immunocytochemistry (ICC), using an appropriate panel of markers showed it to be a case of ERMS. Interestingly, though, not as frequent as on cytologic smears; INCIs could be appreciated even on biopsy material. INCIs in an ERMS are highly unusual and, to our knowledge, have not been documented so far. As a result of lack of any such cases in the literature, at present, the significance of this unique finding is not clear, and therefore needs to be investigated, as and when such cases are encountered in the future. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.     

Cytological detection of lymphoma in Douglas aspirate

Except in primary effusion lymphoma (PEL), serous effusions with lymphomatous cells in non-Hodgkin lymphoma (NHL) are not frequently seen as first manifestation of disease. In NHL lymphoplasmacytic lymphoma (LPL) the spleen, lymph nodes, and bone marrow are frequently sites of disease and this type of NHL is usually associated with a serum paraprotein of IgM type accompanied by the clinical syndrome of Waldenstr?m macroglobulinemia. Our patient with NHL LPL type presented in this report had less frequently seen involvement of gastrointestinal tract and clinically was first manifested as effusion in Douglas space. Cytological evaluation as well immunoanalyses of effusion in such cases is essential, and various ancillary studies, because of differential diagnostic problems of lymphomas in serous effusions, first include reactive lymphocytoses and small round-cell tumors (SRCT). In our patient, cytology of effusion revealed cytomorphologically atypical lymphomatous cells with plasmocytoid differentiation. Immunocytochemical and flow cytometry analysis confirmed lymphoid cell differentiation and pathohistological diagnosis of CD20(+) LPL was set after pathohistological analysis of resected ileum.     

Comparison of immunocytochemical sensitivity between formalin-fixed and alcohol-fixed specimens reveals the diagnostic value of alcohol-fixed cytocentrifuged preparations in malignant effusion cytology

The most commonly used fixative in effusion cytology is formalin. In the present study, the immunocytochemical properties of formalin-fixed and alcohol-fixed specimens were compared to evaluate the usefulness of alcohol-fixed cytocentrifuged preparations for routine cytologic diagnosis. A total of 269 effusion samples and 17 primary antibodies were used. The sensitivity of immunocytochemical studies in alcohol-fixed specimens was similar and correlated to that of formalin-fixed specimens, suggesting that alcohol-fixed cytocentrifuged preparations are useful in effusion cytology. Pretreatment with or without heat-induced antigen retrieval revealed that antigen retrieval was unnecessary for immunocytochemical studies with most primary antibodies in alcohol-fixed cytocentrifuged preparations. The present study describes the use of immunocytochemical studies with alcohol-fixed cytocentrifuged preparations for diagnosis in routine effusion cytology.     

Cytologic features of small-cell carcinoma on ThinPrep

The use of ThinPrep (TP) technology for fine-needle aspiration (FNA) cytology has become widely accepted. However, some literature suggests that small-cell carcinoma may present a diagnostic pitfall due to morphologic alterations. In this study, we retrospectively compared 14 FNA of small-cell carcinoma prepared using TP with corresponding conventional smears (CS). We also examined the TP appearance of 23 other small round-cell lesions in order to determine if differential diagnostic features were preserved. TP and CS were evaluated semiquantitatively for background, architecture, chromatin quality, nuclear molding, nuclear smearing, nucleolar prominence, amount of cytoplasm, nuclear size, and single-cell necrosis. The data were analyzed using the McNemar chi(2) test. TP slides of small-cell carcinoma showed a cleaner background than CS (P < 0.005). Although some degree of nuclear molding was preserved, it was decreased in amount (P < 0.025) and subtler in quality. Similarly, nuclear smearing was present but decreased in amount (P < 0.05), and less prominent qualitatively. The amount of discernible cytoplasm was greater on TP (P < 0.005). No significant differences were found for any of the other parameters studied. The presence of nuclear molding was the single most useful feature in differentiating small-cell carcinoma from other small round-cell tumors on TP. Small-cell carcinoma may be diagnosed with confidence by FNA using TP. However, pathologists should be aware of certain morphologic alterations in order to avoid diagnostic pitfalls.     

FNA biopsy of small round cell tumors of childhood: Cytomorphologic features and the role of ancillary studies

Pediatric tumors which are conventionally considered to be small round cell tumors (SRCTs) include the prototypical neuroblas-toma as well as rhabdomyosarcoma (RMS), Ewing's sarcoma (ES), malignant lymphoma, and primitive neuroectodermal tumor (PNET). Other malignancies may be considered in the differential diagnosis such as small-cell osteogenic sarcoma, un-differentiated (anaplastic) hepatoblastoma, granulocytic sarcoma, blastemal type Wilms' tumor, and desmoplastic small-cell tumor of the peritoneum. The cytomorphologic features of conventional SRCTs is presented as well as the utility of ancillary studies performed on the aspirated material in making a specific and correct diagnosis. The role of the immediate cytologic assessment of the aspirate is stress, since this is a critical step in formulating an initial diagnostic impression that should prompt the need for additional material for pertinent ancillary studies. Although challenging, FNA cytology of SRCTs of childhood can be diagnostic in the majority of cases, allowing specific therapy to be given to patients with unresectable SRCTs without a tissue biopsy as well as documenting recurrent and/or metastatic disease. © 1994 Wiley-Liss, Inc.     

Cytologic characteristics of congenital mesoblastic nephroma in fine-needle aspiration cytology: a case report.

The cytologic features of congenital mesoblastic nephroma (CMN) as recognized in smears of fine-needle aspirated cytology (FNAC) are reported. These included spindle- and tadpole-shaped cells with round to oval nuclei having small nucleoli and a smooth contour. The cytoplasm of these cells was dense and homogeneously stained. The background was composed of mucoid fibrillar material. The findings appear to be different from other types of renal tumors in infancy and specific enough for this tumor to allow diagnosis by FNAC.     

Fine-needle aspiration (FNA) cytology diagnosis of small round cell tumors: value and limitations

Small round cell tumors (SRCTs) are a group of malignancies (non-Hodgkin lymphoma, neuroblastoma, retinoblastoma, hepatoblastoma, nephroblastoma, rhabdomyosarcoma, small cell anaplastic carcinoma, Ewing sarcomal peripheral neuroectodermal tumor, and desmoplastic small round cell tumor), characterized both cytologically and histologically by a predominantly small round to oval, and relatively undifferentiated cells. Together they form a formidable group and an overwhelming majority of childhood malignancies. The patients may present in later (inoperable) stage with huge intrathoracic and intraabdominal mass, when chemotherapy and/or radiation therapy may be the first or only line of treatment. As a less invasive procedure fine needle aspiration (FNA) cytology has definite advantage over surgical excision biopsy to arrive at a tissue diagnosis before initiation of therapy. Because of the morphologic similarities, the SRCTs may pose a differential diagnostic problem in the practice of clinical cytology, especially when they are poorly differentiated. Important cytomorphological features, which help in the identification of various SRCTs include completely dissociated cell population and lymphoglandular bodies (cytoplasmic fragments) in non-Hodgkin lymphoma (NHL), eosinophilicfibrillar material and Homer-Wright rosettes along with cellular processes in neuroblastoma, acinar formation in hepatoblastoma, blastema cells with tubular differentiation in nephroblastoma, tadpole shaped cells in embryonal rhabdomyosarcoma, extreme nuclear molding and perinuclear blue inclusion in small cell anaplastic carcinoma (SCAC), irregular, punched out and large cytoplasmic vacuolations due to glycogen in Ewing sarcoma, and sheets of undifferentiated small round cells surrounded by collageneous stroma in desmoplastic small round cell tumor (DSRCT). Some of these features such as nuclear molding, rosette, and acinar formation are noticed in more than one type of SRCTs. Moreover, the characteristic cytomorphological features may be present in 70-80% cases and for categorization of the remaining cases, contribution from ancillary studies is essential. It is suggested that cytomorphological features along with one or more of the parameters such as special stains (cytochemistry), immunocytochemistry (ICC), electron microscopy (EM), tissue culture, DNA ploidy, karyotype and molecular analysis can increase the diagnostic accuracy of SRCTs. However, these facilities may not be available in all the laboratories, especially in the developing countries, and even if available in a limited form, a tissue diagnosis has to be offered often by FNA cytology based on morphological features, as a life saving measure in seriously ill patients before the results of ancillary studies are finalized.     

Serous effusions in malignant lymphomas: a review

Serous effusions are a common complication of lymphomas. Although the frequency of pleural effusion is 20-30% in non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD), the involvement of peritoneal and pericardial cavities is uncommon. Among lymphoma subtypes, T-cell neoplasms, especially the lymphoblastic lymphomas, more frequently involve the serous fluids. The thoracic duct obstruction and impaired lymphatic drainage appear to be the primary mechanism for pathogenesis of pleural effusion in HD and direct pleural infiltration is the predominant cause in NHL. There is wide variation in rate of positive cytologic findings of NHL in pleural effusion (22.2-94.1%). Cytologic features of specific lymphoma subtypes such as lymphoblastic lymphoma, follicular center cell lymphoma, including Burkitt-type lymphoma, marginal zone lymphoma, MALT lymphoma, and anaplastic large-cell lymphoma, etc., have been described in the literature. The differential diagnostic problems of lymphomas in serous effusions include reactive lymphocytoses, early involvement by lymphomatous process, small round-cell tumors (SRCT), and presence of look-alike of Reed-Sternberg cells. To overcome these difficulties, various ancillary studies, including immunocytochemistry (ICC), morphometry, flow cytometry (FCM), and cytogenetics/molecular genetics (PCR, in-situ hybridization, and Southern blotting), have been performed on effusion specimens. ICC not only distinguishes lymphomas from reactive lymphocytoses and SRCTs, it significantly modifies the morphologic diagnosis to achieve a better classification of lymphomas. Combined morphology and immunophenotyping by FCM, has a sensitivity as well as specificity of 100%. Morphometry also distinguishes reactive lymphocytoses from malignant lymphoma with a high degree of sensitivity (>85%) and specificity (>95%). Limitations of individual ancillary techniques can be overcome by using multiple parameters. Although lymphomas rarely present as serous effusions without the involvement of other thoracic and extrathoracic sites, a small group of lymphomas called primary effusion lymphomas (PEL) exhibit exclusive or dominant involvement of serous cavities, without a detectable solid tumor mass. This body cavity based lymphoma (BCBL) is a distinct clinicopathologic entity and is found predominantly in AIDS patients with preexisting Kaposi sarcoma. In the absence of obstructive or infiltrative tumor mass, its pathogenesis has been attributed to stimulation by vascular endothelial growth factor (VEGF)/vascular permeability factor (VPF), leading to vascular leakage. Cytomorphologically, PEL is usually a large-cell lymphoma, which appears to bridge features of large-cell immunoblastic and anaplastic large-cell lymphoma (ALCL). Most of these cases comprise a unique subgroup of B-cell lymphoma, with features of both high-grade anaplastic and B-immunoblastic lymphoma, but T-cell and/or natural killer cell immunophenotypes are described. Its association with various viral DNAs has been studied in detail by molecular techniques. Pleural effusion due to lymphomas, either primary or otherwise, is considered as one of the factors adversely influencing overall survival. The presence of pleural effusion at the time of presentation is not only associated with extremely poor outcome of lymphomas, it is also a predictor of disease relapse after chemotherapy and decreased survival. When the patients of lymphomatous pleural effusions with and without mediastinal mass present in respiratory distress, thoracocentesis is the initial diagnostic and therapeutic choice in these patients. In such situations, cytology along with ancillary studies not only gives a quick diagnosis of lymphoma, but also offers prognostically significant information such as classification of lymphomas, its grade and immunophenotype, and presence/absence of viral DNAs and tumor lysis syndrome.     

Embryonal adenoma of the kidney: A report of two cases

Embryonal (metanephric) adenoma of the kidney, like Wilms' tumor, exhibits small monomorphic, blue cells arranged as vague, tubular rosettes. Unlike Wilms' tumor, which requires chemotherapy or multi-modality therapy for optimal management, the available evidence indicates that embryonal adenoma is most likely cured by simple enucleation or nephrectomy. Two women, age 54 (Case 1) and 78 (Case 2), respectively, underwent needle biopsy for a radiologically well circumscribed renal lesion with associated hematuria. The cellular smears contained vague rosette-like arrangement of small, blue cells with scant cytoplasm and evenly distributed, fine, nuclear chromatin. In cell blocks, these cells were arranged as compact, primitive, tubular rosettes or rare, more-solid clusters. Assuming that the absence of undifferentiated blastema and primitive glomeruli represented a sampling error, a diagnosis suggesting of Wilms' tumor was made in Case 1. At nephrectomy, despite extensive sampling, the typical triphasic Wilms' morphology and anaplastic or necrotic areas were not seen. In the presence of architectural monotony, the diagnosis in Case 1 was amended to embryonal adenoma. Case 2 was cytologically diagnosed as embryonal adenoma of the kidney and is being followed conservatively. In our opinion, the presence of monotypic architecture at cytology/histology is very helpful in differentiating renal embryonal (metanephric) adenoma from Wilms' tumor. Diagn. Cytopathol. 16:42–46, 1997. © 1997 Wiley-Liss, Inc.