Case report and review of immunodeficiency-associated Burkitt lymphoma

Study of the mechanism by which dinaciclib induces apoptosis and cell cycle arrest of lymphoma Raji cells through a CDK1-involved pathway

Objective

This study aimed to identify and evaluate the mechanism by which apoptosis and cell cycle arrest were induced by dinaciclib in lymphoma Raji cells.

Methods

The colony formation assay was used to detect cell proliferation of Raji cells. Cell cycle arrest and cell apoptosis were determined by flow cytometry and TUNEL assays, respectively. Protein expression related to the Raji cell state was evaluated by Western blot. The Raji/Dinaciclib drug‐resistant cell line was established, where the regulating functions of CDK1‐involved pathway were verified. In addition, the effect of dinaciclib in vivo was examined in orthotopically implanted tumors in nude mice.

Results

Cell apoptosis was induced, and DNA synthesis ability was decreased in a time‐dependent manner in dinaciclib‐treated lymphoma Raji cells. Furthermore, the cell cycle was found to be blocked in the G2/M Phase. Further study indicated that CDK1‐involved pathway played a key regulatory role in this process. It was revealed by cell transfection that the expression of cell cycle proteins was downregulated after treatment with dinaciclib through a CDK1‐involved pathway, which eventually led to apoptosis. Knockdown of CDK1 restored the sensitivity of the Raji/Dinaciclib cells to dinaciclib. Xenograft model of nude mice showed that dinaciclib treatment in vivo could effectively inhibit tumor growth, consistent with the experiment results mentioned before.

Conclusion

In this study, we clarified the mechanisms through which dinaciclib induces Raji cell apoptosis and blocks the cell cycle through a CDK1‐involved pathway, which supported that dinaciclib had potential values in the treatment of lymphoma.

Burkitt lymphoma masquerading as Tolosa-Hunt syndrome in an HIV-seropositive patient

PURPOSE

To describe a rare case of Burkitt lymphoma metastatic to the cavernous sinus that was initially diagnosed as Tolosa-Hunt syndrome.

CASE DESCRIPTION

A 31-year-old confirmed and treatment-compliant HIV-positive Hispanic male acutely developed diplopia, ptosis, numbness in the V1 distribution, and complete external ophthalmoplegia in the right eye over 1 week. Imaging showed a mass-like lesion within the right cavernous sinus without other intracranial abnormalities. He was started on broad-spectrum antibiotics and antifungals without improvement. Inflammatory and infectious workup was negative. A presumed diagnosis of Tolosa-Hunt syndrome was made based on clinical and radiographic findings, as well as the absence of another etiology to explain the patient's presentation. He was then started on high-dose oral steroids with improvement of orbital pain only. Shortly after being discharged on steroids, the patient returned to the hospital with severe abdominal pain. Computed tomography of the abdomen showed perforated ileitis with aneurysmal dilation of the ileum and marked wall thickening concerning for a mass lesion. Positron emission tomography-computed tomography showed an uptake in the terminal ileum and right cavernous sinus consistent with metastatic Burkitt lymphoma, matching with pathology. After several cycles of chemotherapy, symptoms improved, and he regained full ocular motility in the affected eye. However, the patient ultimately died due to peritonitis and pyelonephritis.

CONCLUSION

Burkitt lymphoma metastatic to the cavernous sinus was diagnosed after an initial diagnosis of Tolosa-Hunt syndrome. Tolosa-Hunt syndrome is a diagnosis of exclusion and should only be made after ruling out other pathologies.

B-cell Lymphoproliferative Disorders Associated with Primary and Acquired Immunodeficiency

The diagnosis of lymphoproliferative disorders associated with immunodeficiency can be challenging because many of these conditions have overlapping clinical and pathologic features and share similarities with their counterparts in the immunocompetent setting. There are subtle but important differences between these conditions that are important to recognize for prognostic and therapeutic purposes. This article provides a clinicopathologic update on how understanding of these B-cell lymphoproliferations in immunodeficiency has evolved over the past decade.