I. Green et al., A SPECTRUM OF CYTOMORPHOLOGIC VARIATIONS IN MEDULLARY-THYROID CARCINOMA - FINE-NEEDLE ASPIRATION FINDINGS IN 19 CASES, Cancer cytopathology, 81(1), 1997, pp. 40-44
BACKGROUND, Medullary thyroid carcinoma (MTC), a rare malignancy with
a variety of morphologic appearances, can mimic both primary and metas
tatic lesions of the thyroid gland and give rise to diagnostic problem
s when these tumors are aspirated. Although cytopathologic features of
MTC have been well described, this study was undertaken to define and
elaborate further, subtle morphologic variations, the recognition of
which would be helpful in the diagnosis of MTC. METHODS. A retrospecti
ve review of 19 cases of histologically confirmed MTC was conducted. F
ine-needle aspirations were performed by endocrinologists or cytopatho
logists using a 23- or 25-gauge needle. Smears were stained with Diff-
Quik, Papanicolaou, or hematoxylin and eosin (H&E) stain. Cell blocks
were routinely prepared, and 4-micron sections were stained with H&E.
RESULTS. Certain cytologic features, such as eccentric nuclei, neuroen
docrinelike nuclei, inconspicuous nucleoli, binucleation and multinucl
eation, ill-defined cytoplasmic borders, and a clean background, were
present in all cases. Additional helpful features seen in some but not
in all cases included syncytial groups of cells, round to oval and sp
indle shapes, dendritic cell processes, the presence of amyloid, and n
uclear molding and grooves. CONCLUSIONS, The authors found that MTC co
uld be adequately diagnosed by fine-needle aspiration, despite the fre
quent cytomorphologic variations, based on a set of features consisten
tly present in all the cases included in this study. Features such as
neuroendocrinelike chromatin and nuclear molding have not been previou
sly described. (C) 1997 American Cancer Society.