Transient spontaneous regression of aggressive non-Hodgkin's lymphoma confined to the adrenal glands

Primary adrenal diffuse large B cell lymphoma: a clinicopathological and molecular study from China

Primary adrenal lymphoma is a rare entity that, in most cases, is derived from B cells. The most commonly seen primary adrenal lymphoma is diffuse large B cell lymphoma (DLBCL). To better understand the clinicopathological and molecular features of these tumors, we studied 14 Chinese patients with DLBCL who initially presented with an adrenal tumor. The clinicopathological features of the 14 primary adrenal DLBCL cases were retrospectively reviewed using immunohistochemistry, immunoglobulin gene rearrangement analysis, evaluation of Epstein-Barr virus status, and fluorescence in situ hybridization. Patient age ranged from 43 to 69 years, with a mean age of 58 years. The patients most commonly presented with abdominal pain and adrenal mass. Ten patients exhibited bilateral adrenal masses, and four had unilateral adrenal masses (three left, one right). Thirteen of 14 DLBCLs were DLBCL not otherwise specified, and one was an intravascular large B cell lymphoma. According to the algorithm of Hans et al. (Blood 103:275-282, 2004), 13 and 1 cases were classified as the non-germinal center B-cell-like subtype and the germinal center B-cell-like subtype, respectively. The Ki-67 index ranged from 35 to 80%. Epstein-Barr virus-encoded RNA was detected by in situ hybridization in 6 of the 12 available cases. Two patients showed BCL-6 rearrangements. The follow-up period ranged from 1 to 87 months. During the follow-up period, four patients died of the disease, five were alive with the disease, four were alive without disease, and one was lost during the follow-up period. In summary, most primary adrenal lymphomas are non-germinal-center B-cell-like subtype DLBCLs, which have high proliferative activity and a poor prognosis.

Spontaneous regression of an EBV-associated monoclonal large B cell proliferation in the mastoid of a young child following surgical biopsy

We report the spontaneous regression of an Epstein-Barr virus-associated monoclonal lymphoid proliferation in an immunocompetent child. A 2-year-old male with acute otitis media presented with a right-sided facial palsy secondary to acute mastoiditis. During mastoid decompression a polypoid mass, a histologically diffuse large B cell lymphoma, was found. Staging revealed localized disease. At surgical re-exploration 5 weeks later the disease had resolved. Retrospective serological testing was consistent with an acute Epstein-Barr viral infection and in situ hybridization of the tumour tissue was positive for Epstein-Barr RNA.

Spontaneous Regression of Follicular, Mantle Cell, and Diffuse Large B-Cell Non-Hodgkinʼs Lymphomas Detected by FDG–PET Imaging

Spontaneous regression of non-Hodgkin lymphoma (NHL) has been reported in low-grade tumors but is an extremely rare event in intermediate- and high-grade disease. Documentation of spontaneous regression by serial fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging has not been reported in the literature. We present 3 cases of spontaneous regression, 1 each of follicular lymphoma (FL), mantle cell lymphoma (MCL), and diffuse large B-cell lymphoma (DLBCL), which showed spontaneous regression on serial FDG-PET imaging. All patients underwent serial whole-body FDG-PET scans 60 minutes after intravenous injection of 9-11 mCi of this radiotracer. None of them had any chemotherapy, radiotherapy, or surgery after the baseline PET scan. Spontaneous regression of disease in all 3 cases was correlated with conventional imaging and clinical course. All 3 patients had positive FDG-PET results on their baseline scan. There was complete disappearance of FDG uptake on a follow-up PET scan for the patient with follicular lymphoma. These results suggest complete regression. The patients with MCL and DLBCL both showed a significant reduction in FDG uptake on serial whole-body PET scans, suggesting partial regression in both cases. Although spontaneous regression of lymphoma is uncommon, this phenomenon can be successfully demonstrated by FDG-PET imaging. Therefore, serial PET imaging may play an important role in detecting this unusual event and may further enhance our understanding of the biologic behavior of this malignancy.

Primary Adrenal Lymphoma

Primary adrenal lymphoma is a rare extranodal lymphoma with characteristic clinical features including a high incidence of bilateral involvement, predominantly diffuse large B-cell histology, and a low incidence of extra-adrenal disease at diagnosis. Patients are most commonly older men presenting with fever, lumbar pain, and/or symptoms of adrenal insufficiency. Prolonged disease-free survival appears uncommon, which may reflect a publication bias and/or the presence of additional adverse prognostic factors at diagnosis in most patients. Given the rarity of this disease, no prospective chemotherapy studies have been reported. Unresolved therapeutic issues include the optimal chemotherapy regimen (with vs. without monoclonal antibody), the role of bilateral adrenalectomy and/or adjuvant radiation therapy, and the need for central nervous system prophylaxis, given recent reports raising the possibility of a high risk of parenchymal or meningeal relapse. Multicenter collaborative retrospective reviews and prospective trials are needed to address these issues.

Autonomous histopathological regression of primary tumours associated with specific immune responses to cancer antigens

Spontaneous histopathological regression of cancer has been reported. The involvement of the immune system in such regression has been advocated, leading to the theory of immunological surveillance against cancer. A prediction of this theory is that common tumour antigens can be recognized upon repeated exposure by cell-mediated immunity, which leads to tumour regression and the subsequent appearance of tumour antigen-loss variants. However, no direct evidence has been provided in non-viral-induced experimental animal models of primary malignancy or in human primary cancer. This study examined two groups of melanoma patients where histopathological regression of the primary tumour was observed. Many of the 23 patients with multiple (> or =3) primary melanomas showed significant regression of their last melanoma (median 33%, mean 40) compared with matched melanomas from patients with a single primary melanoma (median 0%, mean 12) (p=0.0080), or compared with their first primary melanoma (p=0.0013). Regression was consistent with an 'immunization effect' seen in murine tumour transplantation studies, where inoculation with > or =3 asynchronous tumours induces transplantation rejection on subsequent challenge. A significant decrease in the expression of the melanoma common tumour antigen MART-1 in the last primary tumour from multiple melanoma patients (median 8%, mean 24) versus matched single melanoma patients (median 79%, mean 68) (p=0.0041) and in the last versus first tumour in multiple primary patients was found (p=0.0083). Metastases from 17 patients whose primary skin melanomas had completely regressed (occult primary melanoma) also showed significant MART-1 loss (median 0%, mean 11) compared with matched metastases from patients with non-regressing primary melanoma (median 51%, mean 50) (p=0.0013). MART-1 antigen-loss variants observed in the multiple primary and occult primary patients correlated with the presence of peripheral blood MART-1-specific cytotoxic T lymphocytes (CTLs) (p=0.03). No similar effects were observed with two other melanoma antigens, gp100 and CD63. Thus, in two groups of human melanoma patients, evidence is provided for histopathological tumour regression associated with cancer immune surveillance.