Changing cytologic and histologic utilization patterns in the diagnosis of 515 primary lung malignancies

Over the last decade, the specimen types used to diagnose primary pulmonary malignancies at the authors' institution have changed in terms of their frequency of submission.

The authors reviewed pathologic findings in 216 cases of primary lung carcinoma diagnosed during the years 1983-1984 (earlier period) and compared these with the findings in 299 cases diagnosed during the years 1993-1994 (later period).

The total number of transbronchial fine-needle aspirates (TBNA) increased from 13 to 206 (P < 0.0001), the total number of sputum (SP) samples declined from 236 to 36 (P < 0.0001), and the total number of forceps endobronchial biopsy (FBX) specimens increased from 61 to 119 (P = 0.0023) between the earlier period and the later period. The positivity rate of some specimen types was similar for these two periods (transthoracic percutaneous fine-needle aspirate [PFNA], 95% and 97%; bronchial washings, 61% and 60%), but the positivity of others improved by a statistically nonsignificant degree (bronchial brushings, 61-71%; FBX, 59-69%). The positivity of TBNA was 57% in 1993-1994. The collective positivity of bronchoscopic cytology specimens was significantly higher than simultaneous FBX during both periods (P = 0.0032), but bronchoscopic histology and cytology were complementary. The positivity of fiberoptic bronchoscopy (FOB) improved significantly, from 72% in 1983-1984 to 85% in 1993-1994 (P = 0.0059). During both periods, an equivalent proportion of patients were subjected to each of 3 major invasive sampling procedures (FOB, 70%; PFNA, 20%; open surgical biopsy, 10%). Fifteen patients were diagnosed by SP cytology without an invasive procedure in 1983-1984, but none were diagnosed by SP cytology in 1993-1994.

TBNA and increased utilization of FBX have displaced postbronchoscopy SP examination, generating higher positivity for FOB. Bronchoscopic cytology and histology were complementary, but radiologically guided fine-needle aspiration was the procedure with the highest positivity.