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.

Needle aspiration cytology of pancreatic cystic lesions.

Forty-two histologically confirmed cases of pancreatic cystic lesions with cytologic evaluation by needle aspiration biopsy (NAB) were reviewed. There were 21 inflammatory pseudocysts (IPC), nine mucinous cystic neoplasms (MCN), six microcystic serous adenomas (MSA), one macrocystic serous adenoma, and five papillary solid and cystic neoplasms (PSCN). Correct cytodiagnosis was made in all cases of IPC and MCN. The contents of IPCs were characterized by turbid or blood-tinged fluid containing cellular debris, numerous foamy macrophages, and other inflammatory cells. There were few or no epithelial lining cells. The aspirates from MCNs showed gelatinous mucoid material containing mucus-secreting cells that were present singly, in clusters, or in sheets. Depending on the individual case, benign or malignant columnar cells, or an admixture of these cells, were present in a mucinous background. The preoperative needle aspirates of five MSAs were acellular. In one case of MSA and in one example of macrocystic serous adenoma, small monolayered sheets of benign cubic epithelial cells were seen in the needle aspirates. Similar cytologic findings were noted in the materials obtained by intraoperative NAB performed under direct vision of the aforementioned five MSAs. Difficulties were encountered in typing three PSCNs that yielded in NAB cells resembling those of an islet cell tumor. They were diagnosed as low-grade neoplasms (PSCN vs. islet cell tumor). In two other patients, a cytodiagnosis of PSCN was correctly made as the NAB revealed monomorphic tumor cells wrapping around small capillary blood vessels.

Hashimoto's thyroiditis: cytodiagnostic accuracy and pitfalls.

To determine the cytodiagnostic accuracy rate and pitfalls of Hashimoto's thyroiditis (HT), the files and smears prepared from the thyroid needle aspirates of 146 patients with suspected HT and/or clinically and serologically confirmed HT were reviewed. Of those patients, 105 presented with a diffuse and rubbery thyroid enlargement, and 41 with one or two prominent nodules. For the first group (105 patients), the needle aspiration biopsy (NAB) was performed on one or two thyroid lobes during their initial endocrinologic consultation, and for the second group (41 patients), the NAB was performed on and around the predominant nodules that were found either at initial physical examination or during the patients' routine follow-ups. In 134 cases, a cytodiagnosis of HT was made on the first NAB. Among the 41 patients with a prominent thyroid nodule, a thyroid neoplasm was suspected clinically in four because their thyroid nodules increased in size. In the other 12 patients, a cytodiagnosis of follicular neoplasm (FN) was made in five cases, and a Hürthle cell tumor (HCT) was diagnosed or suspected in seven patients. All 16 patients had thyroid surgery, and a HT was histologically confirmed in all cases. In the first four patients, no tumor was found. Among five patients with a cytodiagnosis of FN, one had a hyperplastic follicular cell nodule (HFCN), two had follicular adenomas, and two had papillary carcinomas of follicular variant. For the seven patients with a cytodiagnosis of HCT, HCT was confirmed in three, three were found to have hyperplastic Hürthle cell nodules (HHCN), and one showed a benign colloid nodule with Hürthle cell changes and remote hemorrhagic necrosis. It is concluded that NAB is highly sensitive in diagnosing HT, with a diagnostic accuracy rate of 92% by the first biopsy attempt. The cytologic differential diagnosis between an HFCN and a follicular neoplasm and between an HHCN and an HCT is impossible in some cases.

Leiomyosarcoma of the kidney. Report of a case diagnosed by fine needle aspiration cytology and electron microscopy.

A 41-year-old man presented with a large abdominal tumor that yielded, in the fine needle aspiration biopsy, dyshesive, pleomorphic malignant cells. Electron microscopy of the aspirated material revealed nonepithelial cells showing intracytoplasmic bundles of microfilaments with vague focal densities and micropinocytotic vesicles along the cell membrane, suggesting a malignant leiomyosarcoma, which was confirmed by microscopic examination of the resected right kidney. The patient died four months after surgery from widespread metastases.

Needle aspiration cytology of acinar-cell carcinoma of the pancreas: report of a case with diagnostic pitfalls and unusual ultrastructural findings.

A case of histologically and ultrastructurally confirmed acinar-cell carcinoma of the pancreas examined by needle aspiration cytology is reported. The aspirate showed isolated and loosely clustered cells with variable granular cytoplasm, and central or eccentrically located oval hyperchromatic nuclei displaying prominent nucleoli, suggesting a pancreatic neuroendocrine tumor. Numerous intracytoplasmic zymogen granules and several microtubules within cisternae of rough endoplasmic reticulum (MCRER) were found by electron microscopic study of metastatic tumor tissue. Cytodiagnostic pitfalls of this rare pancreatic cancer are discussed as well as the diagnostic value of MCRERs.

Small cell anaplastic carcinoma of the prostate: report of a case with positive urine cytology.

A case of small-cell anaplastic carcinoma of the prostate, occurring in an 82-year-old man with prior prostatic adenocarcinoma, is reported. The exfoliated tumor cells in the urine were seen singly or in loose aggregates with molding. They showed scant cytoplasm and slightly pleomorphic, hyperchromatic nuclei with inconspicuous nucleoli. By electron microscopy the tumor consisted of primitive epithelial cells without glandular or neuroendocrine differentiation. The tumor pursued a highly aggressive course, and the patient died of metastatic disease 4 mo after the diagnosis.

Cavitating pneumonia caused by Corynebacterium group JK.

Corynebacterium group JK organisms were isolated from lung fluid aspirated with a fine needle from one of four thick-walled cavitary lesions in a 72-year-old female. Cultures and stains for mycobacteria and fungi were negative. The patient was successfully treated with an 8-week course of vancomycin.