RESUMO
Burkitt lymphoma (BL) is a poorly differentiated non-Hodgkin B-cell lymphoma, more frequent in children than in adults. The extranodal debut of the disease is rare. We report a 43-year-old male patient with history of dyspnea. Burkitt lymphoma diagnosis was reached after biopsy of a pleural lesion. An initial staging F-FDG-PET/CT revealed large high-uptake lymphatic clusters in mediastinum, lung hilum, and extranodal involvement in pleura, pericardium, periphery of liver and spleen, all the omentum and peritoneum down to the pelvic floor, and bone marrow infiltration.
Assuntos
Linfoma de Burkitt/diagnóstico por imagem , Imagem Multimodal , Tomografia por Emissão de Pósitrons , Tomografia Computadorizada por Raios X , Adulto , Fluordesoxiglucose F18 , Humanos , Masculino , Compostos RadiofarmacêuticosRESUMO
The use of PET in patients with marginal zone B cell lymphoma (MZL) is controversial because of variability of fluorodeoxyglucose (FDG) avidity. We analyzed 40 PET/CT in 25 consecutive patients to compare its performance with CT at staging and as a first-line response assessment. Sensitivity of PET/CT and CT was 96 and 76%. Mean standard uptake value was 6.1, 6.9 and 3.4 (p = 0.3) in nodal, extranodal and splenic subtypes, respectively. Of 17 patients (extranodal: n = 9; nodal: n = 6; splenic subtype: n = 2) with both imaging tests available at diagnosis, 8 (47%) had more involved areas with PET/CT than with CT, 75% of which were extranodal lesions. PET/CT resulted in upstaging of five patients although treatment of only two of them was changed. Responses of 15 patients with post-treatment PET/CT were the following: 9 negative and 6 positive of which 3 were isolated residual lesions. Progression was documented in two of these three patients. Response was also assessed by CT in 11 patients. Discrepancies were found in three: Two were in complete remission by CT while PET/CT detected localized residual disease; another patient was in partial remission by CT, whereas PET/CT showed only one positive lesion. Two of these three patients relapsed. Patients with negative post-treatment PET/CT did not relapse. With a median follow-up of 50 months (10-152 months), 3-year overall survival was 100 and 80% for patients with negative and positive post-treatment PET/CT (p = 0.2). Three-year disease-free survival was 86%; the negative predictive value (NPV) was 100%, and the positive predictive value (PPV) was 83.3%. Although a larger number of patients will be required to further confirm these data, we can conclude that PET/CT is a useful imaging tool for both staging and response assessment in patients with nodal and extranodal MZL as a result of its high sensitivity, NPV and PPV.