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Cytodiagnosis of metastatic amelanotic melanomas by fine‐needle aspiration biopsy
Author(s) -
Lai Raymond,
Redburn Jim,
Nguyen GiaKhanh
Publication year - 1998
Publication title -
cancer cytopathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.052
H-Index - 304
eISSN - 1097-0142
pISSN - 0008-543X
DOI - 10.1002/(sici)1097-0142(19980425)84:2<92::aid-cncr4>3.0.co;2-f
Subject(s) - pathology , medicine , fine needle aspiration , cytology , biopsy , cytopathology , metastatic carcinoma , amelanotic melanoma , melanosome , cancer , sarcoma , nucleolus , melanoma , carcinoma , biology , cancer research , melanin , genetics , nucleus , psychiatry
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, premelanosomes, 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. Cancer (Cancer Cytopathol) 1998;84:92‐7. © 1998 American Cancer Society.