Maxillary sporadic Burkitt's lymphoma associated with neuro-orbital involvement in an Indian male

Sporadic Burkitt Lymphoma Involving the Orbit - A Report of Two Cases and Review of Literature

Burkitt lymphoma (BL) is an aggressive, rapidly growing B-cell non-Hodgkin lymphoma found predominantly in children and has three clinical subtypes. The sporadic subtype, seen in non-endemic areas, typically presents as an abdominal mass. Primary orbital involvement is rarely reported. We report two cases of sporadic orbital BL manifesting as unilateral rapidly progressive proptosis with orbit being the initial site of presentation. Following an incision biopsy, BL was confirmed on histopathology and immunohistochemistry. Both patients demonstrated a remarkable improvement with systemic chemotherapy. Burkitt lymphomas grow rapidly with the potential for vision loss. Albeit rare, clinicians should be aware of this entity as timely diagnosis and initiation with chemotherapy display a dramatic response.

Adult Burkitt lymphoma- an Island between lymphomas and leukemias

Background: Burkitt lymphoma is a rare, aggressive and rapidly fatal, B-cell non-Hodgkin’s lymphoma. It has an incidence of 0.4/100,000 age-adjusted to the USA standard population. Here we describe the case of a 77-year-old patient who presented with Burkitt lymphoma.

Case: A 77-year-old male presented to his primary care physician with fatigue and listlessness and was referred to the hospital with a white blood cell count (WBC)-23.7 K/uL (neutrophils 37%, lymphocyte 11%, blasts 9%) and platelets-19 K/uL. During his stay in the hospital, repeat investigations revealed WBC-29.9 K/uL (neutrophils 22%, lymphocyte 27%, atypical lymphocytes 5%, blasts 20%) and platelets-10 K/uL with no evidence of mucosal bleeds, neck or abdominal masses or generalized lymphadenopathy. Bone marrow aspirate revealed the presence of MYC rearrangements (8q24) on flow cytometry and fluorescent in-situ hybridization (FISH), indicative but not typical of BL. He was transfused with platelets due to a rapidly deteriorating platelet count and episodes of epistaxis. He was discharged after four days with a plan of outpatient chemotherapy over a period of 4 months. An Ommaya reservoir was placed in the right ventricle for intrathecal chemotherapy. After four months of chemotherapy, computerized tomography of the chest, abdomen, and pelvis confirmed remission. A magnetic resonance imaging of the brain a month after completion of chemotherapy revealed metastatic lymphoma in the temporal, parietal and occipital lobes. He was discharged to hospice for palliative care.

Conclusion: Unconventional presentations, as seen in our case of a leukemia-like picture in the absence of a bulky disease, are the quagmire that might delay aggressive management and result in poorer outcomes.

Orbital lymphoma

Orbital lymphomas constitute 50-60% of ocular adnexal lymphomas. A total of 2211 cases of orbital lymphoma with a known subtype have been reported in the last 24 years (1994-2017). The vast majority of orbital lymphomas are of B-cell origin (97%), of which extranodal marginal zone B-cell lymphoma (EMZL) (59%) is the most common subtype, followed by diffuse large B-cell lymphoma (23%), follicular lymphoma (9%), and mantle cell lymphoma (5%). Orbital lymphoma is primarily a disease of the elderly. Gender distribution varies according to lymphoma subtype. However, extranodal marginal zone B-cell lymphoma (53%) and follicular lymphoma (75%) show a female predominance, whereas diffuse large B-cell lymphoma shows an even gender distribution. Mantle cell lymphoma has a striking male predominance of 80%. The histopathological subtype and the clinical stage of the disease are the best indicators of prognosis and patient outcome. Low-grade lymphomas such as extranodal marginal zone B-cell lymphoma and FL have a good prognosis, whereas high-grade lymphomas (diffuse large B-cell lymphoma and mantle cell lymphoma) are associated with a poor prognosis. When managing solitary low-grade lymphomas, radiotherapy is the treatment of choice. Chemotherapy, with or without radiotherapy, should be chosen for disseminated and high-grade lymphomas.

Inhibition of histone deacetylase 6 (HDAC6) protects against vincristine-induced peripheral neuropathies and inhibits tumor growth

As cancer is becoming more and more a chronic disease, a large proportion of patients is confronted with devastating side effects of certain anti-cancer drugs. The most common neurological complications are painful peripheral neuropathies. Chemotherapeutics that interfere with microtubules, including plant-derived vinca-alkaloids such as vincristine, can cause these chemotherapy-induced peripheral neuropathies (CIPN). Available treatments focus on symptom alleviation and pain reduction rather than prevention of the neuropathy. The aim of this study was to investigate the potential of specific histone deacetylase 6 (HDAC6) inhibitors as a preventive therapy for CIPN using multiple rodent models for vincristine-induced peripheral neuropathies (VIPN). HDAC6 inhibition increased the levels of acetylated α-tubulin in tissues of rodents undergoing vincristine-based chemotherapy, which correlates to a reduced severity of the neurological symptoms, both at the electrophysiological and the behavioral level. Mechanistically, disturbances in axonal transport of mitochondria is considered as an important contributing factor in the pathophysiology of VIPN. As vincristine interferes with the polymerization of microtubules, we investigated whether disturbances in axonal transport could contribute to VIPN. We observed that increasing α-tubulin acetylation through HDAC6 inhibition restores vincristine-induced defects of axonal transport in cultured dorsal root ganglion neurons. Finally, we assured that HDAC6-inhibition offers neuroprotection without interfering with the anti-cancer efficacy of vincristine using a mouse model for acute lymphoblastic leukemia. Taken together, our results emphasize the therapeutic potential of HDAC6 inhibitors with beneficial effects both on vincristine-induced neurotoxicity, as well as on tumor proliferation.

Histone deacetylase 6 activity is critical for the metastasis of Burkitt's lymphoma cells

Background

Burkitt’s lymphoma is an aggressive malignancy with high risk of metastasis to extranodal sites, such as bone marrow and central nervous system. The prognosis of metastatic Burkitt’s lymphoma is poor. Here we sought to identify a role of histone deacetylase 6 (HDAC6) in the metastasis of Burkitt’s lymphoma cells.

Methods

Burkitt’s lymphoma cells were pharmacologically treated with niltubacin, tubacin or sodium butyrate (NaB) or transfected with siRNAs to knock down the expression of HDAC6. Cell migration and invasion ability were measured by transwell assay, and cell cycle progression was analyzed by flow cytometry. Cell adhesion and proliferation was determined by CellTiter-Glo luminescent cell viability assay kit. Cell morphological alteration and microtubule stability were analyzed by immunofluorescence staining. Effect of niltubacin, tubacin and NaB on acetylated tubulin and siRNA efficacy were measured by western blotting.

Results

Suppression of histone deacetylase 6 activity significantly compromised the migration and invasion of Burkitt’s lymphoma cells, without affecting cell proliferation and cell cycle progression. Mechanistic study revealed that HDAC6 modulated chemokine induced cell shape elongation and cell adhesion probably through its action on microtubule dynamics.

Conclusions

We identified a critical role of HDAC6 in the metastasis of Burkitt’s lymphoma cells, suggesting that pharmacological inhibition of HDAC6 could be a promising strategy for the management of metastatic Burkitt’s lymphoma.