Bone marrow trephine immunohistochemistry is useful in characterizing malignancy-associated myelonecrosis: A retrospective observational study.

Abstract

We aim to describe the utility of immunohistochemistry (IHC) in characterizing malignancy-associated myelonecrosis (MN) on bone marrow trephine biopsies (BMBx) as a part of initial workup. Patten and intensity of antigenic immunoexpression in necrotic tumor cells on BMBx were evaluated in a series of cases using standardized avidin-biotin-complex immunoperoxidase technique after heat-induced epitope retrieval and compared the same with viable tumor cells wherever available. Fifteen out of 2494 (0.6%) cases (median age: 28years; range: 4 to 66years) had evidence of MN (extensive in eight, moderate in five, and focal in two) secondary to hematological (N=9) and solid (N=6) malignancies. Five (33.3%) had pancytopenia, and eight (53.3%) had difficult and/or hemodiluted aspirate. Antigenic expression for CD10, CD79a, CD3, CD7, and CD20 was retained by necrotic leukemic blasts or lymphoma cells; CD34, TdT, and PAX5 showed heterogeneous expression; and a weak Golgi zone (dot like) CD30 positivity was noted in Reed-Sternberg (RS) or RS-like giant cells. Necrotic epithelial metastases retained pancytokeratin in all and showed variable positivity for prostate-specific antigen, carcinoembryonic antigen, CK20, ER, PR, and GATA3. Necrotic neuroblastomas (N=2) retained positivity for synaptophysin and chromogranin, whereas retained nuclear positivity for NKX2.2 in necrotic Ewing family of tumor (N=1) aided in early diagnosis. Myelonecrosis may retain tumor antigenicity, and immunohistochemistry using selected panel of antibodies should be tried in such challenging cases for an early presumptive diagnosis and further decision making.