Date Published: September 6, 2012
Publisher: Hindawi Publishing Corporation
Author(s): Yiyan Liu.
Patients with HIV infection often have generalized lymphadenopathy and/or other lymphoid proliferation and are at significantly increased risk for lymphoma. This study retrospectively evaluated the diagnostic value of concurrent nasopharyngeal lesion and lymphadenopathy on positron emission tomography-computed tomography (PET-CT) with fluorine-18 fluorodeoxyglucose (FDG PET-CT) imaging. The eligible cases were from patients with HIV infection and lymphadenopathy and referred for FDG PET-CT to evaluate lymphoma or other malignancies prior to pathological investigation. FDG PET-CT images and interpretation reports were correlated with clinical information and pathological diagnoses. Among 22 eligible patients, FDG avid nasopharyngeal lesions were incidentally noted in 7 on PET-CT imaging, and all had lymphomas diagnosed with subsequent biopsies (6 diffuse large B-cell lymphomas and 1 Hodgkin’s lymphoma). In the remaining 15 patients with adenopathy but no visible nasopharyngeal lesion or uptake on PET-CT imaging, 9 had biopsies and lymphomas were diagnosed in 4. The patients with FDG avid retroperitoneal or intra-abdominal lymphadenopathy had a greater possibility of lymphoma, compared to those with adenopathy localized only in the upper torso. Coexistent FDG avid nasopharyngeal lesion and generalized lymphadenoapthy on PET-CT imaging are indicative of a malignant lymphoma rather than benign lymphproliferative disease or nasopharyngeal carcinoma.
Infection with the human immunodeficiency virus (HIV) leads to selective depletion of the helper/inducer lymphocyte subset and a subsequent acquired cellular immunodeficiency. Simultaneously, B cells may demonstrate hyperactivity and proliferation . Therefore, many patients infected with HIV have persistent generalized lymphadenopathy and/or other lymphoid proliferation and are at significantly increased risk for lymphoma . Without histopathological evidence, the differential diagnosis is difficult when nodes are relatively small, but imperative between benign or inflammatory lymphoid activation and malignant lymphoma.
This retrospective study was approved by the Institutional Review Board of the University of Medicine and Dentistry of New Jersey. Relevant cases were identified through a search of a computerized database of patients who underwent PET-CT imaging at the Advanced Imaging Center, University Hospital between 01/2006 and 12/2010. Medical records were retrospectively reviewed for laboratory and pathological information.
Total 22 patients or scans met the inclusion criteria. Based on the PET-CT findings, 22 patients were divided into two groups.
HIV infection causes depletion of CD4-positive lymphocytes with consequent immunodeficiency. HIV infection also causes, by direct or indirect mechanisms, both reactive and neoplastic changes in lymphoid tissue. Nasopharyngeal adenoidal hypertrophy is common in patients with HIV infection on pathologic study. In a report by Barzan et al. , 80% of 36 HIV-positive patients had pathologically confirmed nasopharyngeal lymphatic tissue hypertrophy. Most published observations suggested that nasopharyngeal lesions in HIV-infected patients were reactive and represented follicular hyperplasia [8, 9], but malignant lesions were also reported in nasopharyngeal lesions of patients with HIV infection . There was a case report about malignant transformation of nasopharyngeal lymphoid hypertrophy . However, to date there is no publication specifically regarding the nasopharyngeal abnormalities on FDG-PET-CT imaging in patients with HIV infection.
Although reactive nasopharyngeal lymphoid hypertrophy is commonly seen on pathological studies in HIV infection, FDG avid nasopharyngeal lesion on PET-CT imaging may only appear late in the spectrum of HIV infection. Concurrent conditions of nasopharyngeal lesion and lymphadenopathy have a higher diagnostic value for malignant lymphoma especially NHL and are relatively specific for lymphoma rather than a benign/inflammatory process or other neoplasms such as nasopharyngeal carcinoma.