Myelonecrosis: A Clinicopathological Study from a Tertiary Care Center in South India over a Twelve-Year Period

Post-chemotherapy Changes in Bone Marrow in Acute Leukemia With Emphasis on Detection of Residual Disease by Immunohistochemistry

Introduction

In acute leukemia, the leading cause of treatment failure is disease relapse leading to a low level of complete remission and short overall survival. Post-chemotherapy marrow examination gives vital clues regarding treatment response and marrow regeneration.

Aim

We aimed to study the histomorphological changes in post-chemotherapy bone marrow in acute leukemias, monitor residual disease by immunohistochemistry (IHC) on trephine biopsy, and correlate survival status.

Method

This study was a prospective clinical study. A total of 155 post-induction cases (acute myeloid leukemia [AML] - 68 and acute lymphoblastic leukemia [ALL] - 87), from January 2014 to December 2015, were included with a follow-up of 4-28 months. A detailed histomorphology was studied in all cases. IHC was applied in 88 cases of post-induction marrow, which showed morphologic suspicion of an increase in blasts.

Observations

Post-induction marrow was hypercellular in 55.9% of AML and normocellular in 56.3% of ALL. Regenerative hematopoiesis was noted in 37.4% of AML and 88.5% of cases of ALL. Marrow serous atrophy and stromal edema were associated with delayed recovery of counts and their recovery duration ranged from one to five months. Twenty-seven bone marrow aspirates were unsatisfactory, and their trephine biopsies were showed remission in 20 cases and stromal changes in nine cases. In addition, trephine biopsy picked up residual leukemic blasts in four cases in which aspirate showed remission status. Post-induction marrow IHC with scattered positivity for blasts showed sustained remission in 96% cases, and in those with clustered positivity, 28.6% showed residual disease, and 7.2% showed relapse at the end of the study period. The median survival duration was 13, 3, and 12 months for cases with sustained remission, residual disease, and relapse, respectively. There was a statistically significant difference in median survival of patients in the three groups (sustained remission, residual disease, and relapse) (p=0.000).

Conclusion

We conclude that histomorphology augmented by IHC on trephine biopsy gives valuable information regarding post-chemotherapy changes and residual disease status. Bone marrow trephine biopsy is an important tool to assess the remission status of patients with acute leukemia.

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

OBJECTIVE

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.

MATERIALS AND METHODS

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.

RESULTS

Fifteen out of 2494 (0.6%) cases (median age: 28 years; range: 4 to 66 years) 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.

CONCLUSION

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.

Role of Immunohistochemistry in Acute Leukemias with Myelonecrosis

Myelonecrosisis a rare antemortem finding most commonly seen in haematopoeitic neoplasms, especially in acute leukemia. When myelonecrosis occurs at the time of presentation, it imposes certain diagnostic issues in sub categorization of leukemias which is necessary for therapeutic as well as prognostic purposes. Flow cytometry, though is a powerful modality, has its own limitations especially when the cells are not fresh and viable; and when the specimen is not of adequate cellularity which is usual in cases of myelonecrosis. In such situations, immunocytochemistry (ICC) or immunohistochemistry (IHC) may play a major role in lineage specification in leukemias as the necrosed marrow with the ghost cells can still retain the antigenicity for certain immunomarkers. Four such interesting cases of common B acute lymphoblastic leukemia (ALL) where IHC was used for diagnosis were included. ICC and IHC done on the necrosed marrow contributed to the diagnosis of ALL in all the four cases and contributed to subsequent management. ICC and IHC if contributory can play a major role in identifying the primary cause of myelonecrosis as the ghost cells can retain the antigenicity despite being morphologically non-viable.