This is a review of the fine‐needle aspirates (FNAs) of nine pilomatrixomas (PMs) found in a series of 1,500 FNAs performed on skin nodules. The objective is to determine and list the cytologic findings that might mislead the less‐experienced cytopathologist and to give him advice on how to avoid such errors. The following recommendations are made: 1) The FNAs should be carried out and the smears interpreted by the same person. 2) Clinical data, particularly age and location, are of paramount importance. 3) Shadow cells are pathognomonic of PMs. 4) Basaloid nuclei with prominent nucleoli should not be overdiagnosed. 5) Use both Papanicolaou and Diff‐Quik stains. 6) Think of PM when performing and interpreting aspirations from subcutaneous growths located in the head and neck of young persons. Diagn Cytopathol 1996;14:75–83. © 1996 Wiley‐Liss, Inc.

This is a review of the fine‐needle aspirates (FNAs) of nine pilomatrixomas (PMs) found in a series of 1,500 FNAs performed on skin nodules. The objective is to determine and list the cytologic findings that might mislead the less‐experienced cytopathologist and to give him advice on how to avoid such errors. The following recommendations are made: 1) The FNAs should be carried out and the smears interpreted by the same person. 2) Clinical data, particularly age and location, are of paramount importance. 3) Shadow cells are pathognomonic of PMs. 4) Basaloid nuclei with prominent nucleoli should not be overdiagnosed. 5) Use both Papanicolaou and Diff‐Quik stains. 6) Think of PM when performing and interpreting aspirations from subcutaneous growths located in the head and neck of young persons. Diagn Cytopathol 1996;14:75–83. © 1996 Wiley‐Liss, Inc.

No abstract

We describe one case of Merkel cell tumor (MCT) of the eyelid diagnosed by fine-needle aspiration (FNA). The main cytologic features were: isolated cells, loose cohesive sheets, and rosette-like structures in a hematic background. The cells were round to ovoid and very uniform. Chromatin was finely granular and frequent mitotic figures were observed. Under close scrutiny small faintly stained juxtanuclear "caps" were seen. A strong dot-like positivity for CK22 and NFP was observed in the position corresponding to the "caps." NSE positivity was diffuse, although a weak dot-like positivity was seen in some cells. S-100 was negative. Both the cytologic features and the immunocytologic profile of Merkel cell tumor are very characteristic. FNA enables an early and confident diagnosis of this aggressive tumor and an early planning of surgery.

No abstract