Cytopathology of insular carcinoma of the thyroid.

Four pure insular carcinomas (IC) and one IC with focal anaplastic carcinoma (AC) of the thyroid with cytologic evaluation by fine-needle aspiration (FNA) were reviewed. The needle aspirates from the four pure ICs revealed abundant monomorphic follicular cells present singly, in small, loose aggregates, and in cohesive trabecular and acinar clusters. Tumor cells showed fragile, ill-defined, granular cytoplasm and oval nuclei with conspicuous or inconspicuous nucleoli. The case of IC with focal AC yielded, in addition to the follicular cells as seen in the FNA of the 4 cases of pure IC, large pleomorphic malignant cells with prominent nucleoli that were characteristic for an AC, giant-cell type. No intact insulae of tumor cells were identified in any of the 5 cases. Thus, a thyroid IC may be suspected if abundant cohesive and dyshesive monomorphic follicular cells are present in the tumor FNA. However, a firm diagnosis of thyroid IC can only be made by histologic examination of the excised tumor.

Epithelioid leiomyosarcoma of the uterus with oncocytic change.

We report on a rare case of epithelioid leiomyosarcoma of the uterus with oncocytic change and aggressive clinical behavior. The tumor arose in the left lateral wall of the uterus and measured 22 cm in greatest dimension. Histologically, it consisted of solid sheets of round and polygonal cells displaying a homogeneously eosinophilic cytoplasm and pleomorphic nuclei with prominent nucleoli. Six mitotic figures were found per 10 high-power fields in the most mitotically active areas, and focal tumor cell necrosis was present elsewhere. Under electron microscopy, numerous normal-appearing mitochondria and occasional bundles of microfilaments with focal densities were noted in the tumor cell cytoplasm, and poorly-formed external basal lamina and occasional pinocytic vesicles were found on the cell membrane of some tumor cells.

Cytopathology of papillary oncocytic carcinoma of the thyroid in fine-needle aspiration biopsy.

The fine-needle aspirates from two histologically, immunohistochemically, and ultrastructurally confirmed encapsulated papillary oncocytic carcinoma of the thyroid revealed large and small papillary tumor tissue fragments consisting of fibrovascular cores covered with polygonal cells showing abundant and granular cytoplasm and small, oval nuclei. Abundant single and loosely clustered tumor cells with similar cytologic features were also present. Nuclear pleomorphism, irregular nuclear contours, nuclear grooves, and intranuclear cytoplasmic inclusions were not observed in any tumor cells. The two patients were alive and well and showed no evidence of tumor recurrence and/or metastatic disease 6 and 8 years after their thyroid surgeries, respectively.

Cytodiagnosis of bronchogenic carcinoma and neuroendocrine tumor of the lung by transthoracic fine-needle aspiration.

To evaluate our experience with the cytodiagnosis of primary lung cancers by transthoracic fine-needle aspiration (TFNA), 106 bronchogenic carcinomas (BC) and 6 neuroendocrine tumors of the lung (NTL) with adequate needle aspirates were reviewed. The cytodiagnostic accuracy rates of BCs were 75.5%, 72%, 100%, 53%, and 50% for bronchogenic adenocarcinomas, squamous-cell carcinomas, small-cell carcinomas, large-cell carcinomas, and mixed carcinomas, respectively. Of the 6 NTLs, 4 typical carcinoid tumors (CT) were correctly diagnosed, 1 atypical CT was wrongly identified as small-cell carcinoma, and 1 large-cell NTL was mistaken for an adenocarcinoma.

Cytopathology of pleural mesotheliomas.

Pleural mesothelioma is a rare and highly malignant tumor that has shown increasing incidence. In approximately 90% of patients the tumor manifests initially as recurrent, unilateral, bloody pleural effusions; in the remaining 10% of patients the tumor is detected by chest radiography. As a result, pleural mesotheliomas can be diagnosed by cytologic examination of pleural effusions or transthoracic fine-needle aspirates; the cytologic manifestations of such an examination are described in detail. Additionally, the handling of cytologic specimens, diagnostic problems, and the value and limitations of immunocytochemical and electron microscopic studies and other ancillary techniques in the cytologic identification of pleural mesotheliomas are discussed.

Cytopathology of malignant mesothelioma of the pleura in fine-needle aspiration biopsy.

The cytologic findings in fine-needle aspiration biopsy (FNAB) of 9 histologically, immunohistochemically, and ultrastructurally confirmed malignant mesotheliomas of the pleura were reviewed. There were 4 epithelial malignant mesotheliomas (EMM), 3 sarcomatous mesotheliomas (SM), 1 mixed malignant mesothelioma (MMM), and 1 poorly differentiated malignant mesothelioma (PDMM). In FNAB, three EMMs yielded polygonal malignant cells with oval nuclei and prominent nucleoli, singly, in small sheets, and in tridimensional clusters with smooth or lobulated contours. In one EMM, only atypical mesothelial cells with prominent nucleoli were seen singly and in loose aggregates. In FNAB, two SM showed malignant spindle-shaped cells (MSC) with scant, ill-defined cytoplasm singly and in loose clusters. Cohesive clusters of elongated and polygonal cells with ill-defined, clear cytoplasm and pleomorphic nuclei containing small or prominent nucleoli were observed in one SM, with extensive clear-cell changes. In needle aspirates, the MMM showed polygonal malignant cells in clusters admixed with MSC. The PDMM displayed single and clustered large pleomorphic malignant cells, with prominent single or multiple nucleoli. Electron microscopic examination of minute tissue fragments retrieved from the FNAB in 2 cases of EMM revealed epithelial mesothelial cells with well-formed desmosomes and long slender microvilli (LSM) on the free tumor cell surfaces. In one case, LSM in direct contact with collagen fiber bundles in the tumor tissue matrix were observed, supporting the diagnosis of an invasive EMM. Diagn. Cytopathol. 1999;21:253-259.

Cytodiagnosis of benign and malignant Hürthle cell lesions of the thyroid by fine-needle aspiration biopsy.

Eighty-two Hürthle cell (HC) lesions of the thyroid with cytologic evaluation by fine-needle aspiration biopsy (FNAB) were reviewed. In 17 cases the FNAB was not diagnostic because the fine-needle aspirates (FNAs) were too scanty in cellularity. Among the remaining 65 lesions, there were 45 HC adenomas (HCAs), six non-neoplastic HC nodules (NHCNs), 10 primary HC carcinomas (HCCs), and four metastatic HCCs. Forty-four HCAs were diagnosed as HC tumor (HCT), and one HCA was wrongly diagnosed as medullary carcinoma. All six NHCNs were wrongly diagnosed as HCT. Of 10 primary HCCs, there were diagnosed as HCT and seven as suspected HCC. Four metastatic HCCs were correctly diagnosed. The FNAs from 38 HCAs and four NHCNs were predominantly composed of large monomorphic HCs with oval nuclei, inconspicuous nucleoli, and abundant, well-defined, granular cytoplasm present singly, in acinar arrangement, and in monolayered sheets of variable sizes. Nuclear pleomorphism and prominent nucleoli were noted in seven HCAs and two NHCNs. Occasional small syncytial tumor cell clusters (STCCs) were noted in six cases, and a few naked tumor cell nuclei (NTCN) were observed in 16 cases. The FNAs from 14 HCCs were hypercellular. In all cases tumor cells were relatively small and showed monomorphic or pleomorphic nuclei, prominent nucleoli, and ill-defined cytoplasm. STCCs of variable sizes were present in abundance in 10 cases, and numerous NTCN were noted in 12 cases. In two HCCs, the tumor cells with well-defined cytoplasm were present singly and in cohesive sheets, and no STCCs or NTCN were observed. Thus, the presence of small tumor cells with ill-defined cytoplasm and prominent nucleoli in syncytial clusters and abundant NTCN in the FNA of a thyroid nodule should alert the observer about the strong possibility of an HCC.

Fine-needle aspiration biopsy cytology of hyalinizing trabecular adenomas of the thyroid.

Cytologic smears from fine-needle aspirates of three histologically and ultrastructurally confirmed hyalinizing trabecular adenomas of the thyroid (HTAT) were reviewed. In two cases a cytodiagnosis of HTAT was suggested, and in one patient a diagnosis of trabecular epithelial neoplasm was made. In all three cases, small clusters and sheets of epithelial cells with abundant, filamentous, vacuolated, and ill-defined cytoplasm were present. The nuclei were slightly pleomorphic and showed nuclear overlapping, nuclear grooves, and intranuclear cytoplasmic inclusions. Small and irregular fragments of acellular hyalinized material (AHM) were noted within the tumor cell clusters in the first two cases. In the third patient, large syncytial sheets and anastomotic cords of epithelial cells showing ill-defined, filamentous cytoplasm, slightly pleomorphic nuclei, nuclear overlapping, intranuclear cytoplasmic inclusions, and nuclear grooves were present. Fragments of AHM were not observed within clusters and syncytial sheets of tumor cells.

Fine needle aspiration cytology of the kidney, renal pelvis, and adrenal.

Fine needle aspiration biopsy for cytologic evaluation of mass lesions of the kidney, renal pelvis and adrenal is a safe economic and accurate diagnostic procedure. Tumors and inflammatory or degenerative lesions arising from these organs have characteristic cytologic features permitting their correct identification in the majority of cases.

Needle aspiration cytology of metastatic high-grade transitional-cell carcinomas of the urinary tract.

We reviewed 4 cases of high-grade transitional-cell carcinoma (TCC) of the urinary tract with solitary pulmonary metastases that were studied by transthoracic needle aspiration biopsy cytology. There were two grade II and two grade III TCCs. The two grade II tumors yielded, in needle aspirates, syncytial tumor-cell clusters showing ill-defined, granular cytoplasm and slightly pleomorphic nuclei with inconspicuous nucleoli. In one case the tumor-cell cluster showed a focal acinar arrangement, mimicking cells of an adenocarcinoma. In both cases the electron microscopy (EM) study of aspirated tumor cells revealed epithelial cells with well-formed cell junctions, intracytoplasmic vesicles, apical short microvilli, and focal interdigitation of lateral cell membranes, suggesting a urothelial neoplasm. The two grade III TCCs yielded, in needle aspirates, pleomorphic malignant cells singly and in small clusters, showing well-defined, granular cytoplasm and pleomorphic nuclei containing prominent nucleoli, suggesting a poorly differentiated adenocarcinoma or an anaplastic large-cell carcinoma. By EM examination the aspirated tumor cells from one case revealed well-formed cell junctions, intracytoplasmic vesicles, poorly formed microvilli, and focal interdigitation of lateral cell membranes, suggesting a urothelial differentiation. In the other case the tumor cells were pleomorphic cells with occasional cell junctions and no ultrastructural features as seen in the other 3 cases of TCC. The tumor cells from the two grade II TCCs showed strong immunopositive reaction with keratin 7 antibody and weakly positive reaction with carcinoembryonic antigen antibody (CEAA), while those of the two grade III TCCs displayed only a weak and focal immunopositive staining with keratin 7 antibody and strong reaction with CEAA.

Cytodiagnosis of metastatic amelanotic melanomas by fine-needle aspiration biopsy: adjunctival value of immunocytochemistry and electron microscopy.

BACKGROUND: The cytologic diagnosis (CD) of metastatic amelanotic melanomas (MAM) is challenging because the tumor cells may mimic those of a carcinoma or a sarcoma in cytologic materials obtained by fine-needle aspiration biopsy (FNAB). METHODS: Thirty-five well documented cases of MAM at different anatomic sites with cytologic evaluation by FNAB were reviewed. RESULTS: In 31 cases a correct CD was made based on the cytologic and immunocytochemical (IM) findings. The MAMs were characterized by abundant dyshesive pleomorphic malignant cells containing prominent nucleoli and occasional intranuclear cytoplasmic inclusions. The tumor cells stained positively with S-100 and/ or HMB-45 antibodies. There were four cases with unusual cytologic manifestations and equivocal IM characteristics requiring electron microscopic examination (EME) of the aspirated tumor cells to identify intracytoplasmic melanosomes, pre-melanosomes, or microtubules within cisternae of rough endoplasmic reticulum (MCRER) to establish a diagnosis of MAM. CONCLUSIONS: A correct CD of MAMs may be made in a large number of cases by routine cytologic findings and IM staining with S-100 protein and HMB-45 antibodies. However, EME is necessary to demonstrate melanosomes, premelanosomes, or MCRER in cases with unusual cytologic and equivocal IM manifestations.