Fine needle aspiration biopsy of XXXX . A morphologic analysis of 174 cases.

@entity5 @entity1 @entity320 @entity3
The prognostic and therapeutic decisions in cases of @entity320 depend upon the morphologic documentation of @entity3 , which may rapidly and accurately be done by fine needle aspiration (FNA) biopsy of clinically suspicious lesions. The @entity5 cells derived from @entity320 demonstrate a wide range of appearances, however, and other @entity5 may be mimicked. Furthermore, additional @entity5 of other types are more frequent in @entity320 @entity1 : the possibility of a new @entity5 must be considered if the morphology of the @entity5 cells is uncharacteristic. Therefore, a study was undertaken to analyze the morphologic changes seen in FNA biopsy specimens from metastatic @entity320 and to determine which features could be the most useful in establishing a definitive diagnosis. A total of 174 consecutive cases, comprising 151 malignant aspirates and 23 inconclusive aspirates, were reviewed. The most significant features for identification of @entity320 over other @entity5 types were the cell shape and nuclear position, the presence of numerous isolated neoplastic cells and occasional binucleated or multinucleated cells. Intracellular melanin in neoplastic cells was diagnostic when present, but it was absent in 60% of the cases. Macronucleoli and/or intranuclear cytoplasmic invaginations were characteristic but variable features. Morphology was also found to vary by site and cell type. Lung aspirates were less cellular and more likely to contain melanin. Aspirates of subcutaneous nodules were more often composed of spindle-shaped cells or of other variant cell types. Lymph node aspirates more often yielded epithelioid cells with macronucleoli and/or intranuclear invaginations. Spindle-cell melanomas usually demonstrated inconspicuous nuclei and rarely showed enlarged nucleoli. Epithelioid-cell @entity5 contained multinucleated cells and areas of cell wrapping more frequently than did spindle-cell @entity5 . The findings in this study emphasize that a full awareness of the spectrum of morphologic presentations of @entity320 as well as of the clinical history are needed for greater precision in its diagnosis and for avoidance of the pitfall of misdiagnosing nonmelanomas with similar appearances.
