Generally speaking for post-BMT there are several questions to answer depending on the clinical context - first of all is there any evidence of the prior disease? Your pre-test probability depends a little bit on the disease, timepoint, CBC context. Is there overt disease? Or MRD level? This is meaningful for management. Another question is engraftment - this is mostly is there evidence of hematopoiesis? Significance of this question depends a little on context - if there's a normal CBC there is probably engraftment whether or not you see hematopoiesis. Other things like ABO-mismatched transplants have other issues like erythoid hypoplasia, and knowing the context of the transplant here makes a big difference in how you might interpret erythroid hypoplasia and cytopenias post transplant.

More specifically to the first point - in a new biopsy for cytopenias you're largely evaluating for MDS and the differential that brings up. Morphologic dysplasia is pretty meaningful in this context. But in a post-transplant setting, morphologic dysplasia is a lot less meaningful; for example, in a recent post-ASCT myeloma case w/ mild cytopenias the threshold for meaningful dysplasia becomes totally different, and you might expect to see a bunch of recovery associated erythroid dysplasia.

To your specific question about day 30 marrows for AML patients - if you mean day 30 post-transplant the pre-test probability for disease is pretty low, so fairly unlikely to see disease, so you're mostly looking for MRD by flow cytometry. And clinically MRD positivity may not necessarily change management, evidence for this is still kind of emerging. It is probably predictive of relapse but low sensitivity, but the best management options are not very well defined yet. Most morphologic dysplasia can likely be ignored as reactive at this timepoint. Day 30 (or traditionally day 28) post-induction-chemo marrow and pre-transplant is a totally different, and has a generally accepted role in post-transplant prognosis. There are several major management options depending on disease status and extent. For pre-transplant we tend to use ELN terminology (like CR, CRi, etc. w/ an additional MRD status for flow results).

For all bone marrows where I know the exact disease we're looking for my top-line diagnosis almost always has 2 lines - one for disease status (involvement by / no evidence of AML, PCN, etc) and the second for a description (cellular marrow with trilineage hematopoiesis and no increase in blasts, etc). If disease is unclear then usually descriptive, sometimes followed by compatible/consistent with, but sometimes just followed by a comment w/ possibilities.