Diagnosis of lymphoid lesions in limited samples

Objectives: Advances in interventional techniques allow obtaining samples from most body sites through minimally invasive procedures that yield limited samples. We provide practical guidelines for diagnosis of lymphoid lesions in these samples. Methods: Guidelines for selection of biopsy site and triage of the specimen according to results of rapid on-site evaluation (ROSE), and description of the advantages and limitations of currently available ancillary studies are described, based on the experience of the authors, complemented by a comprehensive review of the literature. Results: Five diagnostic categories are observed at ROSE: (1) preponderance of small cells, (2) large cells, (3) mixed small and large cells, (4) blast-like cells, and (5) rare large pleomorphic cells. Detailed description of the diagnostic work-up and subsequent classification for each of these groups is provided. Conclusions: A definitive diagnosis of lymphoid neoplasms in limited samples is possible in most cases through correlation of morphology, ancillary studies, and clinical scenario.