Spontaneous regression of mantle cell lymphoma: a report of four cases

A 15-Year-Old Boy with Primary Maxillary Bone Anaplastic Lymphoma Kinase-Positive Anaplastic Large Cell Lymphoma Relapsed with Rib Metastasis after Spontaneous Remission of a Maxillary Bone Lesion: A Case Report and Literature Review

Anaplastic large cell lymphoma (ALCL) is a rare form of non-Hodgkin's lymphoma (NHL) in children, accounting for 10-15% of all NHL cases. ALCL is currently classified as follows: systemic anaplastic lymphoma kinase (ALK)-positive, systemic ALK-negative, primary cutaneous, and breast implant-associated ALCL. In children, systemic ALK-positive ALCL is the most common, and patients often present with extranodal involvement. We report a rare case of systemic ALK-positive ALCL with primary bone involvement in a 15-year-old male patient. Primary bone lymphoma is most commonly observed in diffuse large B-cell lymphoma and is extremely rare in systemic ALCL. Therefore, the clinical features and prognosis of primary bone ALCL remain unclear. Our patient had spontaneous remission of primary maxillary bone ALCL after gingival scraping but relapsed 12 months later with rib metastasis. Spontaneous remission of ALCL has been reported frequently in primary cutaneous ALCL and rarely in systemic ALCL. Our case demonstrates for the first time that systemic ALCL can also present as solitary bone involvement that can spontaneously remit. Because systemic ALCL is aggressive and has a risk of relapse, as in our case, it is important to consider ALCL in the differential diagnosis of primary bone lesions and to make a precise pathological diagnosis.

18F-FDG PET/computed tomography may predict the outcome of newly diagnosed indolent non-Hodgkin lymphoma in patients managed with initial 'watch-and-wait' approach

OBJECTIVE

The aim of this study was to investigate the role of F-fluorodeoxyglucose (F-FDG) PET/computed tomography (CT) in the outcome of non-Hodgkin lymphoma (NHL) in patients managed with initial 'watch-and-wait' treatment.

METHODS

Sixteen patients with newly diagnosed NHL treated with initial watchful waiting were retrospectively recruited. They had a baseline F-FDG PET/CT and at least one follow-up PET/CT. The standard uptake values (SUV), metabolic tumor volume (MTV) and total lesions glycolysis (TLG) of lymphoma were measured in PET/CT. They were followed up for at least 2 years or until disease progression. The endpoint was the time to initiation of lymphoma treatment (TLT).

RESULTS

Comparing the baseline and the follow-up PET/CT, four out of 16 patients showed spontaneous regression of lymphoma, three of the 16 patients had stable disease and the remaining nine of the 16 patients had progressive disease in the follow-up PET/CT. After a median follow-up of 32 months (range 14-90 months), 10/16 patients had progressive disease and chemotherapy was initiated. The median TLT was 21.0 months. In univariate analysis, MTV and TLG in baseline PET/CT were significant to predict TLT. Kaplan-Meier curves showed a statistical difference for TLT in the two groups of patients stratified by MTV or TLG at baseline (median TLT, 66.0 months vs. 12.0 months, P = 0.007). However, patients' age, Ann Arbor staging, International Prognostic Index and SUVmax were not significant.

CONCLUSION

A proportion of patients with NHL might experience spontaneous regression of lymphoma. F-FDG PET/CT turned out as a prognostic factor for TLT in patients with NHL under watchful waiting.

HIV-negative plasmablastic lymphoma: report of 8 cases and a comprehensive review of 394 published cases

Background

Human immunodeficiency virus (HIV)-negative plasmablastic lymphoma (PBL) is a rare entity of diffuse large B-cell lymphoma (DLBCL). The clinicopathological features of and optimal treatment for HIV-negative PBL remain largely unknown.

Methods

To gain insight into this distinct lymphoma, we summarized the clinicopathologic characteristics of 8 unpublished HIV-negative PBLs and performed a comprehensive review of 394 published cases.

Results

Of the 8 unpublished PBLs, the median patient age was 53.0 years. Four patients presented with stage IV disease. All 8 patients showed a plasma cell-like immunophenotype. Of the six patients who received anthracycline-based chemotherapy, including two who received bortezomib, three patients achieved a continuous complete response, two patients died due to disease progression, and one patient was lost to follow-up. The other two patients achieved continuous complete response after receiving chemotherapy combined with radiotherapy and surgery. Of the 402 patients, the majority were male, with a mean age of 58.0 years. EBV infection was detected in 55.7% of the patients. The median survival times of the patients who received CHOP or CHOP-like regimens and intensive regimens were not reached and 23.0 months, respectively, and the intensive regimen did not improve the survival outcome (P=0.981). Multivariate analysis showed that EBER remained the only independent factor affecting overall survival (OS).

Conclusion

HIV-negative PBL is a distinct entity with a predilection for elderly and immunosuppressed individuals. Intensive chemotherapy had no apparent survival benefits over the CHOP regimen in terms of OS; the prognosis of this disease is poor with current chemotherapy methods, and treatment remains a challenge.

Abscopal Regressions of Lymphoma After Involved-Site Radiation Therapy Confirmed by Positron Emission Tomography

PURPOSE

Patients with abscopal regressions of lymphoma after palliative involved-site radiation therapy (ISRT), detected on sequential ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET), were identified by audit. A retrospective analysis was subsequently conducted to estimate the frequency of abscopal regression in follicular lymphoma (FL).

METHODS AND MATERIALS

Potential cases were identified at multidisciplinary lymphoma meetings and fulfilled these criteria: (1) palliative ISRT given for histologically confirmed lymphoma, (2) >2 lesions visualized on FDG-PET, (3) >1 unirradiated lesion(s) outside ISRT volume, (4) no systemic therapy delivered <2 months before radiation therapy or between radiation therapy and response assessment, (5) complete metabolic response (CMR) in ≥1 unirradiated lesions detected on serial FDG-PET/CT. All ISRT patients with FL treated in 2016 to 2018 were systematically reviewed.

RESULTS

Seven cases of abscopal regression were identified, including 4 patients with FL. In all cases, a CMR was apparent both within the ISRT volume and in ≥1 unirradiated lesions. One patient each was identified with mantle cell lymphoma (4 Gy in 2 fractions), Hodgkin lymphoma (20 Gy in 3 fractions, then 30 Gy in 15 fractions to the same volume), and Richter transformation of chronic lymphatic leukemia (30 Gy in 10 fractions). The 4 patients with FL received either 4 Gy in 2 fractions (n = 3) or 4 Gy followed 8 months later by 30 Gy in 15 fractions (n = 1). From 2016 to 2018, 29 courses of ISRT were prescribed for multifocal FL, after which 4 of 29 (13.8%) abscopal responses were detected, including in 4 of 9 (44.4%) patients with serial PET scans. Two patients, with relapsed disease after initial abscopal responses, experienced durable CMRs with immunotherapies.

CONCLUSIONS

In 4 of 7 cases, PET-detected abscopal regression of lymphoma occurred after 4 Gy, in 2 of 7 cases after repeated ISRT to the same volume, and in 2 of 7 was associated with subsequent complete response to immunotherapy, consistent with an immune basis for the abscopal effect. Abscopal regressions in FL appear to be more common than previously suspected.

Spontaneous Regression of Clinically Indolent Lymphomas Revealed by 18F-FDG PET/CT

A 48-year-old man and a 55-year-old woman, who were diagnosed with follicular lymphoma and small B lymphocytic cell lymphoma, respectively, underwent initial "watch-and-wait" approach against lymphoma. The initial F-FDG PET/CT of both patients showed multiple FDG-avid lymph nodes in the neck, mediastinum, abdomen, and inguinal regions. During their active surveillance, the follow-up PET/CT of both patients revealed spontaneous regression of lymphoma.