Demystifying the evaluation of a "dry tap".

"Dry tap" refers to the failed aspiration of bone marrow hematopoietic elements. Faulty technique is frequently blamed for a dry tap. But, often, the dry tap is associated with an underlying bone marrow pathology. This study aimed to evaluate the causes of dry tap and assess its clinical relevance. This retrospective observational study was conducted in the Department of Pathology over a period of 1 year, from 1 November 2023 to 31 October 2024. A total of 1327 bone marrow aspirates were reviewed. The definitive diagnosis was established by examining the trephine biopsy. A total of 267 aspirates, for which biopsy was not performed or which had suboptimal biopsies, were excluded from the study. A total of 1060 cases were taken for the final study. We attributed 125 (11.8%) cases that were aparticulate and grossly hemodiluted to a "dry tap." Of these, only 20 (16%) of the dry tap could be attributed to improper or faulty technique because their trephine biopsy was adequate and satisfactory for evaluation. An underlying bone marrow pathology, which could plausibly be the reason for dry tap, was identified in 105 (84%) patients. The most common cause was found to be acute leukemia, accounting for 32.8% of the cases. The laboratories should periodically review the cases yielding a dry tap, and if the corresponding biopsies are adequate, then one must focus on improving the technique of bone marrow aspiration. Moreover, a dry tap should serve as a diagnostic alert rather than a basis for disregard of the operator's technique.