The usefulness of step sectioning of transbronchial lung biopsy specimen in diagnosing sarcoidosis.

To evaluate the usefulness of step sectioning of the transbronchial lung biopsy (TBLB) specimens obtained from patients with suspected sarcoidosis, we examined all TBLB specimens obtained from 132 patients who were diagnosed clinically as having sarcoidosis at our institute. When routine sections of TBLB specimens did not show sarcoid granuloma, we prepared additional serial sections from each block and stained every fifth section with hematoxylineosin (step sectioning). All step sections were examined histologically. With the aid of step sectioning, the diagnostic yield of sarcoidosis increased from 38 percent (18/47) to 47 percent (22/47) in stage 1 patients, and from 57 percent (37/65) to 82 percent (53/65) in stage 2 patients. All of the newly detected granulomas were identified between the first and seventh sections. We conclude that step sectioning is useful method in diagnosing sarcoidosis.