Pathology-related medical malpractice claims frequently concern fine-needle aspirations (FNAs) of breast lesions, and diagnostic errors have been attributed in part to the inadequacy of the specimens. Cytologic criteria for adequate FNA specimens, specifically in cases without malignancy, have not been clearly defined.From January 1988, to August 1995, 669 ultrasonographicguided FNAs of nonpalpable, solid breast lesions with subsequent histologic examination were performed at our institution. From these, 54 cases with cytologic diagnoses of insufficient or nonspecific benign findings were identified. All aspirates were reviewed, and the number and size of the epithelial cell groups were quantitated in each case. By using criteria for adequate aspirates of palpable breast lesions (six or more epithelial cell groups per case with a minimum of 5-10 cells per group), 23 of the 54 aspirates were deemed inadequate and 31 adequate. Eleven (48%) of the inadequate aspirates and 17 (55%) of the adequate aspirates were from histologically confirmed carcinomas (ductal carcinoma in situ, 6; invasive carcinoma, 22, of which 12 were ductal, 7, lobular, and 3, mixed ductal and lobular). For the mammographic diagnoses "probably benign," "indeterminate," and "suggestive of malignancy or malignant," the probability of malignancy in aspirates of adequate cellularity (eg, > 6 epithelial groups) was 9%, 40%, and 93%, respectively.These findings indicate that a significant proportion of breast aspirates still may yield false-negative results despite adequate to high cellularity. Although a definition of adequacy based on cellularity is useful in reducing false-negative results, cellularity alone cannot be relied on in the management of nonpalpable lesions. For mammographic findings that are indeterminate or suggestive of malignancy or malignant, nonspecific FNA findings should be followed by core or excisional biopsy to exclude carcinoma. In a recent review of pathology-related medical malpractice claims, 10% of the cases concerned diagnoses made from fine-needle aspiration (FNA) of breast lesions, and, in many cases, these diagnostic errors were the result of inadequate FNA specimens. 1Because diagnoses given based on findings from breast aspirates frequently dictate subsequent patient management, it is clear that evaluation of the adequacy of such specimens is crucial. Pathologists agree that the adequacy of breast aspirates is influenced by a variety of factors, such as clinical findings, lesion type, and specimen procurement, and, therefore, cannot be evaluated solely on the basis of cytologic findings. Nevertheless, in daily practice, cytologic parameters such as the degree of specimen cellularity traditionally have been considered when assessing the adequacy of a specimen for interpretation. Specific cytologic criteria for FNA specimen adequacy, however, have not been clearly defined and vary among different authors in the number and type of cells, the number of slides, and the number of needle passes required. Some authors requ...

This case report presents the light microscopy, immunocytochemistry, and ultrastructure of the first unequivocal extrarenal rhabdoid tumor occurring in lung. Smears and cell blocks prepared from a fine-needle aspiration biopsy show the cytopathological features of this unusual neoplasm, in this case presenting in a 74-year-old male. Electron microscopy of the surgically resected circumscribed pulmonary mass assisted in establishing the diagnosis by demonstrating the considerable accumulation of cytoplasmic intermediate filaments that characterize cells in extrarenal rhabdoid tumor and account for the hyaline "inclusion" in this particular lesion.

We describe the cytologic features seen in fine-needle aspiration (FNA) specimens from two cases of preoperatively diagnosed lymphoepithelial cyst (LEC) of the pancreas. Pancreatic LEC is a rare, true cyst of uncertain histogenesis that may clinically and radiologically mimic a pseudocyst or cystic neoplasm. Both our patients were middle-aged men who presented with vague abdominal pain. Computed tomography (CT) of the abdomen revealed a mass in or around the pancreas, and CT-guided percutaneous FNA (patient 1) and endoscopic ultrasound-guided FNA (patient 2) yielded paste-like yellowgray material. Cytologic smears showed numerous anucleated squamous cells in a background of keratinous and amorphous debris. A few benign nucleated squamous cells and plate-like cholesterol crystals were also seen. Unlike LEC of the head and neck region, only rare lymphocytes and histiocytes were present. Pancreatic LEC was diagnosed based on these cytologic findings and was histologically confirmed following cyst enucleation (patient 1) and partial pancreatectomy (patient 2). We conclude that preoperative FNA and recognition of the characteristic cytologic pattern will enable conservative surgical management of pancreatic LEC.

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