Plasmablastic lymphoma of the oral cavity in an HIV-positive patient: staging with 18F-FDG PET/CT

HIV-related Malignancies and Mimics: Imaging Findings and Management

The risk of developing malignancy is higher in patients with human immunodeficiency virus (HIV) infection than in non-HIV-infected patients. Several factors including immunosuppression, viral coinfection, and high-risk lifestyle choices lead to higher rates of cancer in the HIV-infected population. A subset of HIV-related malignancies are considered to be acquired immunodeficiency syndrome (AIDS)-defining malignancies, as their presence confirms the diagnosis of AIDS in an HIV-infected patient. The introduction of highly active antiretroviral therapy (HAART) has led to a significant drop in the rate of AIDS-defining malignancies, including Kaposi sarcoma, non-Hodgkin lymphoma, and invasive cervical carcinoma. However, non-AIDS-defining malignancies (eg, Hodgkin lymphoma, lung cancer, hepatocellular carcinoma, and head and neck cancers) now account for an increasing number of cancer cases diagnosed in HIV-infected patients. Although the number has decreased, AIDS-defining malignancies account for 15%-19% of all deaths in HIV-infected patients in the post-HAART era. Most HIV-related malignancies in HIV-infected patients manifest at an earlier age with a more aggressive course than that of non-HIV-related malignancies. Understanding common HIV-related malignancies and their specific imaging features is crucial for making an accurate and early diagnosis, which impacts management. Owing to the weakened immune system of HIV-infected patients, other entities such as various infections, particularly opportunistic infections, are prevalent in these patients. These processes can have confounding clinical and imaging manifestations that mimic malignancy. This article reviews the most common AIDS-defining and non-AIDS-defining malignancies, the role of imaging in their diagnosis, and the imaging mimics of malignancies in HIV-infected patients. ^©RSNA, 2018.

Clinicopathological analysis of oral plasmablastic lymphoma: A systematic review

BACKGROUND

Plasmablastic lymphoma (PBL) is a high-grade lymphoma that often affects the oral cavity of HIV-positive patients; however, its prognostic determinants remain unknown.

PURPOSE

To integrate the available data on oral PBL to determine its clinicopathological features and to identify potential prognostic factors.

METHODS

An electronic systematic review was performed using multiple databases with a specific search strategy in February 2018. Inclusion criteria comprised cases diagnosed as PBL affecting the oral cavity and gnathic bones with sufficient data to confirm the diagnoses.

RESULTS

A total of 70 publications were included, representing 153 cases. Oral PBL predominantly affected HIV-positive males (76.4%). EBV was observed in 63.4% of the cases. The gingiva was the most involved site and the lesion usually presented as an asymptomatic swelling. Most cases were classified as stage I (21.6%), and chemotherapy alone was applied in 28.8% of the cases. There was a significant association between HIV and EBV infections, and cases affecting HIV-negative patients were more common in older individuals. Cumulative survival of the patients achieved 42.4% and 33.5% after 2 and 5 years, respectively. Although there were no statistically significant clinicopathological parameters in the univariate analysis, the multivariate Cox regression model demonstrated that EBV-positive status, presence of B-symptoms, and chemotherapy alone were independent prognostic determinants of a poor prognosis.

CONCLUSION

Oral PBL is an aggressive neoplasm with low survival rates, which is influenced by the presence of EBV, presence of B-symptoms, and with the use of chemotherapy only.

Human immunodeficiency virus (HIV)-negative uterine plasmablastic lymphoma on 18F-FDG PET/CT

Plasmablastic lymphoma is a rare and aggressive variant of diffuse large B-cell lymphoma with plasmablastic features, which commonly occurs in the oral cavity of human immunodeficiency virus-positive patients. Here, we present a case of plasmablastic lymphoma involving the uterus in a 54-year-old human immunodeficiency virus-negative female patient. The torso positron emission tomography/CT scan revealed intense ¹⁸F-fludeoxyglucose uptake in a bulky uterus with multiple sites of metastatic disease including peritoneal seeding.

[Plasmablastic lymphoma]

Plasmablastic lymphoma (PBL) is a rare and aggressive subtype of non-Hodgkin lymphoma that commonly occurs in human immunodeficiency virus (HIV)-positive individuals, and affects oral sites. Occasionally, it has been described in HIV-negative patients and involving non-oral sites. Pathologically, PBL is a high-grade B-cell lymphoma that displays the immunophenotype of a terminally differentiated B-lymphocyte with loss of B-cell markers (CD20) and expression of plasma-cell antigens. Epstein-Barr virus infection and MYC rearrangements are frequently observed. Treatment of PBL is challenging because of the lack of established treatment and poor outcomes, with median survival times shorter than one year. In this review, we discuss the clinical and epidemiologic spectrum of PBL as well as its distinct pathological features. Finally, we summarize the currently available approaches for the treatment of patients with PBL.

Reflection of ¹⁸F-FDG accumulation in the evaluation of the extent of periapical or periodontal inflammation

OBJECTIVES

To elucidate whether fluorine-18-labeled ((18)F) fluoro-2-deoxy-d-glucose (FDG) accumulation can reflect the extent of periodontal inflammation, periapical inflammation, or dental caries.

STUDY DESIGN

(18)F-FDG accumulations on positron emission tomography (PET)-computed tomography (CT) were retrospectively compared with the size of the bone resorption areas caused by periodontal inflammation, periapical inflammation, or dental caries on panoramic radiographs, CT, and magnetic resonance imaging (MRI) in 44 subjects.

RESULTS

A significant correlation was found between the size of the bone resorption area caused by periodontal (r = 0.595, P < .01) or periapical (r = 0.560, P < .01) inflammation and the highest standardized uptake value (SUVmax) of (18)F-FDG accumulation. A significant correlation was found between the periodontal (r = 0.622, P < .01) or periapical (r = 0.394, P < .01) inflammatory findings on MRI and the SUVmax of (18)F-FDG accumulation. The SUVmax of (18)F-FDG around most teeth with caries was under 1.5.

CONCLUSIONS

(18)F-FDG accumulation reflects the extent of dental inflammation, not dental caries.

Reactive tonsillar enlargement showing strong 18F-FDG uptake during the follow-up of follicular lymphoma

The 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) has become a standard procedure for the diagnosis, staging, and restaging in lymphoma patients. However, a relative high rate of false-positive results has been reported. We report a case of a 40-year-old man with a previous history of a nodal follicular lymphoma, stage IVA, treated with R-CHOP, which showed strong 18F-FDG uptake in the Waldeyer's tonsillar ring during his follow-up, being considered highly suspicious of relapsed lymphoma. A surgical removal of the palatine tonsils and adenoids was performed, which showed reactive follicular hyperplasia. Furthermore, bone marrow biopsy revealed absence of neoplasia. The patient is still in follow-up with no signs of recurrent lymphoma. This case illustrates that, despite the high sensitivity for the detection of recurrent lymphoma, 18F-FDG uptake should be interpreted with great caution and confirmatory studies should be performed before any therapy.