The accuracy of diagnosing Burkitt lymphoma in serous effusion specimen: A cytological-histological correlation with ancillary studies.

ABSTRACT

OBJECTIVE: The objective of this study is to evaluate the effectiveness of diagnosing Burkitt lymphoma (BL) in serous effusion (SE) specimen and summarise the characteristics of BL in SE. We also assess the utility of a germinal centre-associated marker, LMO2, in the differential diagnosis of BL in SE specimens. METHODS: Eleven cases of malignant SE caused by BL were reviewed. SE cytology and histological biopsy diagnoses were compared to determine the concordance rates. RESULTS: A uniform population of non-cohesive medium-sized lymphoid cells with frequent apoptosis was found on SE smears or cell block sections. Cytoplasmic and nuclear vacuoles presented in seven cases. Immunophenotyping demonstrated positivity for CD79a (three of three cases), CD10 (seven of 11 cases), BCL6 (nine of 11 cases), MUM-1 (one of nine cases), CD20 and MYC (11 cases). LOM2 was negative in nine of nine cases. Both IGH/MYC rearrangement and MYC rearrangement were identified in four of six cases, and two of six cases carried isolated MYC rearrangement or isolated IGH/MYC rearrangement, respectively. The diagnoses of eight BLs and three B-cell non-Hodgkin lymphomas were established according to cytomorphology and ancillary studies. SE cytology provided initial pathological diagnoses for eight cases (six BLs and two non-Hodgkin lymphomas). Histodiagnoses were available for eight cases. The concordance rate of cytological-histological diagnosis was 62.5% (five of eight cases). CONCLUSIONS: Combining cytomorphology and ancillary studies enables the accurate diagnosis of BL in SE specimens. Furthermore, LMO2 may be a useful marker in the differential diagnosis of BL.