spontaneous Remission of an Untreated, MYC and BCL2 Coexpressing, High-Grade B-Cell Lymphoma: A Case report and Literature Review

Abstract

Non-Hodgkin lymphomas (NHL) are a heterogeneous group of hematologic malignancies typically treated with multiagent chemotherapy. Rarely, spontaneous remissions can be observed, particularly in more indolent subtypes. The prognosis of aggressive NHL can be predicted using clinical and histopathologic factors. In aggressive B-cell NHL, the importance of MYC and BCL2 proto-oncogene coexpression (as assessed by immunohistochemistry) and high-grade histologic features are particularly noteworthy. We report a unique case of spontaneous remission in a patient with an aggressive B-cell NHL which harbored high-risk histopathologic features, including MYC protein expression at 70-80%, BCL2 protein expression, and morphologic features suggestive of high-grade B-cell lymphoma, NOS (formerly B-cell lymphoma unclassifiable with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma [BCLU]). After undergoing a biopsy to confirm this diagnosis, he opted to forego curative-intent chemotherapy. The single, yet relatively large area of involvement noted on 18F-fluorodeoxyglucose positron emission tomography-computed tomography steadily resolved on subsequent follow-up studies. He remained without evidence of recurrence one year later, having never received treatment. This case emphasizes the potential for spontaneous remission in NHL and demonstrates that this phenomenon can be observed despite contemporary high-risk histopathologic features.

Case Details

Disease Location

Blood

Personal Characteristics

59 -year-old male no significant medical history was taking vitamin supplements

Clinical Characteristics

Aggressive b-cell nhl which harbored high-risk histopathologic feautres, including myc protein expression at 70-80%, bcl2 protein expression, and morphologic features suggestive of high-grade b-cell lymphoma presented with 3 weeks of abdominal pain and weight loss CT revealed conglomerate lymph nodes surrounding the abdominal aorta measuring 5x6cm, suspicious for lymphoma ldh was elevated at 209u/l CT-guided needle core biopsy, flow cytometry, and fish studies were performed histologic sections of the para-aortic ln conglomerate demonstrated a neoplastic proliferation of large, atypical lymphocytes, arranged in sheets and characterized by intermediate to large-sized nuclei, dense finely granular chromatin, occasionally prominent nucleoli, and sparse cytoplasm numerous mitotic figures and apoptotic bodies were identified ihc, neoplastic cells were uniformly positive for CD20 with intermixed positivity for CD3 on small lymphocytes myc (70-80% positive), bcl2 (>95% positive), and bcl6 (>95% positive) proteins were strongly expressed ki-67 was markedly elevated (>95%) flow cytometry demonstrated an abnormal CD10-positive b-cell population expressing CD19, 20, and 38, with lambda surface light chain expression without CD5, which comprised 70% of the wbcs. Diagnosis of high-grade b-cell lymphoma. Although consultative review agreed with hgbl nhl, but provided differential diagnosis of dlbcl, nos, or hgbl

Remission Characteristics

Within 2 weeks of biopsy, the patient's pain resolved fdg-PET/CT noted intense avidity only in the para-aortic region, consistent with stage i disease. The ln size had decrease from the prior CT to 2.5x2.5cm ldh had also fallen into the normal range declining chemo, the patient was followed up 6 months after his initial diagnosis, a follow-up CT measured the lymph nodes at 1.7x1.4cm and was notable for the absence of the previously visualized hypermetabolic periaortic mass on the fdg-PET. This would be classified as a complete response lab results 1 year after his diagnosis were within normal limits, he had no symptoms or signs clinically to suggest recurrence

Treatment & Mechanisms

Proposed Remission Mechanisms

No major mechanism suspected, however several possibilities stimulation of an antitumor response from the host immune system, particularly immune activation secondary to infection or injury activation of antitumor immunity subsequent to local tissue injury and inflammation from a biopsy has been suggested previously in the literature concomitant viral infections the immune system gaining the ability to recognize and react to malignant cells one mechanism for evading t-cell mediated cytotoxicity receiving extensive attention is expression of inhibitory ligands of immune checkpoint receptors and programmed death ligand

Clinical Treatment

Guided needle biopsy

Non-Clinical Treatment

None reported