Highly well differentiated hepatocellular carcinoma and benign hepatocellular lesions. Can they be distinguished on fine needle aspiration biopsy?
OBJECTIVE
To determine whether highly well differentiated hepatocellular carcinoma can be distinguished from benign hepatocellular lesions on fine needle aspiration biopsy (FNAB).


METHODS
Ninety-five FNABs from 88 patients with hepatic masses/diffuse conditions were reviewed according to new cytologic criteria established by Takenaka et al. They were classified into well-, moderately and poorly differentiated hepatocellular carcinomas (W-, M- and P-HCC) and benign aspirates and histologically verified.


RESULTS
There were 21 W-HCC, 39 M-HCC, 10 P-HCC, 3 problematic and 22 benign aspirates. The most useful criteria for diagnosing highly W-HCC were architectural features on the smears/cell block sections, including hypercellularity; arborescent, cohesive clusters; broad trabeculae; transgressing and peripheral endothelium; and cytologic details of small, monotonous hepatocytes with nuclear crowding, decreased cytoplasm, increased nuclear/cytoplasmic ratio, atypical naked nuclei and tumor giant cells. Well-defined cytoplasmic borders, abundant thick and monotonous cytoplasm, eccentric nuclei, thick nuclear membranes, irregular nuclear contours, increased chromatin density, irregular chromatin distribution and macronucleoli were not always detectable in highly W-HCC. In fact, some of them were seen in dysplastic hepatocytes. Deficient reticulin patterns and diffuse sinusoidal CD34 reactivity were helpful.


CONCLUSIONS
Experience, attention to architectural and cytologic details in smears/cell blocks and clinicopathologic correlation should reduce the number of indeterminate reports. However, there will always remain some cytohistologically challenging cases.
Wee
Aileen
A
Department of Pathology, National University Hospital, National University of Singapore, Singapore, Republic of Singapore. patweea@nus.edu.sg
Nilsson
Barbro
B
D000293:Adolescent; D000368:Aged; D000369:Aged, 80 and over; D001707:Biopsy, Needle; D006528:Carcinoma, Hepatocellular / Q000175:diagnosis* / Q000473:pathology; D002454:Cell Differentiation / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D005260:Female; D020518:Focal Nodular Hyperplasia / Q000175:diagnosis / Q000473:pathology; D006801:Humans; D008103:Liver Cirrhosis / Q000175:diagnosis / Q000473:pathology; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D014463:Ultrasonography