Long-term spontaneous regression of Stage IV diffuse large B-cell lymphoma

Abstract

Diffuse large B cell lymphoma (DLBCL) is an aggressive disorder accounting for >30% of all lymphomas. Its prognosis is poor due to a high relapse rate. Spontaneous regression (SR) in DLBCL is rare, with only a few reported cases. Moreover, almost all of these were low-grade lymphomas with an average SR duration of 13 mo. As the cause of SR is unknown, there are many theories such as trauma, infection, medication, and an antitumor immune response. We present a patient with progressive DLBCL who demonstrated SR for >42 mo. Although treatment for lymphoma usually starts soon after diagnosis, insights into SR of lymphomas may lead to new treatment strategies.

Keywords: Spontaneous regression; diffuse large B-cell lymphoma; long-term remission.

Fig. 1

Changes over time in PET-CT images. (A) Abnormal accumulation of fluorodeoxyglucose in the right lung (middle lobe), 30 mm in diameter, with a standardized uptake value (SUV) of 37.10, and a vaginal mass 40 mm in diameter before biopsy, with a maximal SUV of 47.08. (B) No abnormal accumulation of fluorodeoxyglucose 2 mo after the first PET-CT study. (C) No abnormal accumulation of fluorodeoxyglucose 1 y after the first PET-CT study.

Fig. 2

Photomicrographs of the vaginal-mass biopsy specimen. (A) Diffuse proliferation of lymphoid cells (hematoxylin-eosin [H-E], original magnification x200). Scale bar, 50 μm. (B) Diffuse proliferation of medium-sized to large lymphoid cells with irregular nuclei and features of apoptosis (H-E, x400). Scale bar, 10 μm. Immunohistochemical (C – E) and in situ hybridization studies (F), all x400 with hematoxylin counterstaining and diaminobenzidine chromogen. The lymphoid cells expressed the B-cell marker CD20 (C). Lymphoid cells did not express programmed death ligand 1 (D). Small numbers of CD8⁺ T cells were scattered through the tumor (E; CD8⁺). EBER in situ hybridization showed no signals in lymphoid cells (F). Scale bar, 20 μm.