Fine-needle aspirations of pancreatic serous cystadenomas: improving diagnostic yield with cell blocks and α-inhibin immunohistochemistry.
BACKGROUND
The diagnosis of serous cystadenoma (SCA), a rare benign pancreatic neoplasm, can alter the management of patients with pancreatic masses. Although characteristic imaging findings and fluid chemical analysis have been described, SCAs are not always recognized preoperatively. Furthermore, scant cellular yield on fine-needle aspiration (FNA) often leads to a nondiagnostic or nonspecific benign diagnosis. α-Inhibin (AI), a sensitive marker for SCA, is infrequently required for diagnosis in surgical specimens due to their characteristic histologic appearance. The objective of the current study was to determine whether AI staining can improve SCA diagnosis on FNA specimens.


METHODS
Fifteen confirmed cases of SCA with prior FNA specimens were selected for this study. FNAs were evaluated for cellularity, cellular arrangement, and cytomorphology. Resection specimens were reviewed.


RESULTS
Of the 15 FNA cases, approximately 75% demonstrated scant cellularity (11 of 15 cases). On smears, the cells were arranged as flat sheets, corresponding to strips of cells on cell block sections. The cells were small and round to cuboidal, with clear cytoplasm; occasional plasmacytoid cells and oncocytic cells were identified. Flattened cells, corresponding to attenuated epithelial cells lining macrocysts on the resections, were also noted. Stromal fragments were present in 5 FNAs and correlated with the hyalinized stroma in the resection specimens. AI immunostaining was positive in 88% of cases (7 of 8 of cases), thereby supporting the diagnosis of SCA.


CONCLUSIONS
The results of the current study indicate that low cellularity and bland cytology are inherent to SCAs. Performing cell blocks and AI staining on FNA specimens is useful for establishing the diagnosis of SCA. An immunohistochemical panel including AI, chromogranin, and synaptophysin may enhance the diagnostic accuracy of pancreatic FNA specimens.
Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York.
Marcela
M
Salomao
Helen
H
Remotti
John D
JD
Allendorf
John M
JM
Poneros
Amrita
A
Sethi
Tamas A
TA
Gonda
Anjali
A
Saqi
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D044963:Biopsy, Fine-Needle; D015331:Cohort Studies; D018293:Cystadenoma, Serous / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D007265:Inhibins / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D010180:Pancreatectomy / Q000379:methods; D010190:Pancreatic Neoplasms / Q000175:diagnosis / Q000473:pathology* / Q000601:surgery; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D016610:Tissue Embedding
D015415:Biomarkers; C094377:inhibin-alpha subunit; D007265:Inhibins
inhibin; pancreas; pancreatic cystic neoplasm; pancreatic fine-needle aspiration; serous cystadenoma; α-inhibin