Bone Marrow Conventional Karyotyping and Fluorescence In Situ Hybridization: Defining an Effective Utilization Strategy for Evaluation of Myelodysplastic Syndromes.

OBJECTIVES: The current standard of practice for evaluation of myelodysplastic syndromes (MDS) includes peripheral blood and bone marrow morphology review and conventional karyotyping. Karyotype provides a global view of the chromosome complement while fluorescence in situ hybridization (FISH) targets specific abnormalities. The aim of this study was to determine if an MDS-FISH panel would add value beyond karyotype in MDS workup. METHODS: We studied 505 patients who were evaluated for a possible MDS and had concurrent bone marrow examination, karyotyping, and MDS-FISH performed. RESULTS: In total, 462 cases had adequate karyotyping (≥20 metaphases) and showed excellent concordance (96%, 445/462) between karyotyping and MDS-FISH. Additional FISH abnormalities had no impact on diagnosis and minimal impact on the cytogenetic prognostic scoring in the myeloid neoplasm cases (2%, 4/206). The concordance rate dropped to 82% (32/39) in the group with insufficient karyotyping (<20 metaphases), and additional FISH findings in this subgroup had no impact on the diagnosis but altered the cytogenetic prognostic scoring in 10% (2/20) of myeloid neoplasm cases. CONCLUSIONS: In the evaluation of a possible MDS, FISH rarely provides additional value when karyotype is adequate. We propose a value-based, cost-effective algorithmic approach for conventional karyotyping and FISH testing in routine MDS workup.

Expression of LMO2 is associated with t(14;18)/IGH-BCL2 fusion but not BCL6 translocations in diffuse large B-cell lymphoma.

Diffuse large B-cell lymphoma (DLBCL) can be separated for prognostic purposes using gene expression profiling (GEP) into 2 subgroups: germinal center B-cell (GCB) and activated B-cell phenotypes. However, GEP is impractical for routine clinical use, and immunophenotyping is an imperfect surrogate. Therefore, we studied the relationship between expression of the purported germinal center marker LMO2 and the presence of IGH-BCL2 fusions, BCL6 translocations, and LMO2 translocations. In addition, we investigated the usefulness of LMO2 expression as a marker of GCB subtype in DLBCL. Immunohistochemical and fluorescence in situ hybridization studies were successfully performed on 101 cases of de novo DLBCL that had been incorporated into a tissue microarray. There was a statistically significant association between IGH-BCL2 fusion and LMO2 protein expression (P = .02) but not between BCL6 translocations and LMO2 expression. LMO2 translocations were not identified. Although uncommon, all cases that had both IGH-BCL2 fusion and BCL6 translocations expressed LMO2. The findings suggest LMO2 as a potential marker for the GCB phenotype.

F-18 FDG PET/CT imaging of submandibular gland oncocytoma.

F-18 FDG PET/CT is used to evaluate head and neck malignancies, including salivary gland tumors. We describe the FDG PET/CT features of a submandibular gland oncocytoma. An 85-year-old patient with small cell cancer of the lung and a history of squamous cell carcinoma of the lower lip was evaluated with FDG PET/CT. There was an intensely hypermetabolic left submandibular gland lesion that was suspected for a metastasis. Ultrasound-guided fine needle aspirate of the lesion proved to be a submandibular gland oncocytoma.