[1732] Nonsmall Cell Lung Carcinoma (NSCLC), Not Otherwise Specified (NOS) Diagnosed by Fine Needle Aspiration Biopsy (FNAB): Reviewed with Attempt To Reclassify with a Specific Diagnosis, Based on Classic Cytomorphological Features (CCMF).

Cynthia L Cookingham, Kelly Montoya, Kim R Geisinger. Wake Forest University Health Science, Winston Salem, NC

Background: Treatment options for lung cancer have made specific cell typing of NSCLC significantly more relevant than in the past. A large proportion of NSCLC present with a clinically advanced stage rendering them inoperable & they are often diagnosed by cytology without tissue sampling. A fraction of NSCLC are interpreted as NOS. The aim of this study is to attempt to reclassify NSCLC, NOS into a specific diagnosis using CCMF, allowing more targeted treatment regimens.
Design: 41 FNABs with an initial diagnosis (IDX) of NSCLC, NOS were independently reviewed by 2 pathologists using previously agreed upon CCMFs, including 8 criteria for adenocarcinoma (ACA) & 6 criteria for squamous carcinoma (SCA), in an attempt to reclassify them more specifically. The 41 cases of NSCLC, NOS were mixed with 33 FNABs that had an IDX of ACA (17) or SCC (16) as control cases. All specimens included direct smears with Diff-Quik and Papanicolaou stains; cell blocks were not used .A third independent pathologist organized cases & tallied results.
Results: 74 cases in total were reviewed. Of the 41 NSCLC, NOS, independent, specific cell type agreement by 2 pathologists occurred in 80% of cases, in the remaining 20% a diagnosis was made by consensus conference. Of the 41 cases of NSCLC, NOS a specific diagnosis was made in 33 or 80% of cases. 27 (66%) were classified as ACA, 5(12%) as SCC, and 1(2%) as adenosquamous carcinoma. 20% remained as NSCLC, NOS. Of the 33 controls the pathologists independently agreed in 94% of cases. The major criteria for reclassifying NSCLC, NOS to ACA were delicate cytoplasm, peripherally located nuclei and rudimentary acinar formation; for SCA, polygonal shapes and centrally placed nuclei were the predominant features. A histologic diagnosis was available in 19 of the 74 total cases. The review cytologic diagnosis (RCD) agreed with the tissue diagnosis in 78% of cases. In 3 of the disagreements, the RCD was ACA, whereas the original tissue diagnosis favored SCA; the reverse occurred in one patient.
Conclusions: Many lung cancer patients are treated soley on a FNAB diagnosis, often without the benefit of cell block material for immunohistochemical studies. Most NSCLC, NOS diagnosed by FNAB can be classified specifically by well recognized CCMF alone, thus allowing more specific therapeutic interventions & improved patient care.
Category: Pulmonary

Tuesday, March 1, 2011 1:00 PM

Poster Session IV # 279, Tuesday Afternoon


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