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. © 2012 Springer Science+Business Media New York.73258262Jerusalem, G., Beguin, Y., Fassotte, M.F., Whole-body positron emission tomography using 18F-fluorodeoxyglucose for posttreatment evaluation in Hodgkin's disease and non-Hodgkin's lymphoma has higher diagnostic and prognostic value than classical computed tomography scan imaging (1999) Blood, 94, pp. 429-433Beker, D.B., Berrak, S.G., Canpolat, C., False positivity of FDG-PET/CT in a child with Hodgkin disease (2008) Pediatr Blood Cancer, 50, pp. 881-883Long, N.M., Smith, C.S., Causes and imaging features of false positives and false negatives on F-PET/CT in oncologic imaging (2011) Insights Imaging, 2, pp. 679-698Nakamoto, Y., Tatsumi, M., Hammoud, D., Normal FDG distribution patterns in the head and neck: PET/CT evaluation (2005) Radiology, 234, pp. 879-885Rosenbaum, S.J., Lind, T., Antoch, G., False-positive FDG PET uptake-the role of PET/CT (2006) Eur Radiol, 16, pp. 1054-1065Bhargava, P., Parker, J.A., Dezube, B.J., Pitfalls of diagnosis based on abnormal flow cytometry and [(18)F] fluorodeoxyglucose positron emission tomography (2008) Clin Lymphoma Myeloma, 8, pp. 117-120Crocchiolo, R., Fallanca, F., Giovacchini, G., Role of 18FDG-PET/CT in detecting relapse during follow-up of patients with Hodgkin's lymphoma (2009) Ann Hematol, 88, pp. 1229-1236Hosokai, R., Imai, C., Takachi, T., Reactive tonsillar enlargement with strong 18F-FDG uptake after chemotherapy for tonsillar diffuse large B-cell lymphoma (2011) J Pediatr Hematol Oncol, 33, pp. e87-e88Ioachim, H.L., Medeiros, L.J., Reactive Lymphoid Hyperplasia (2009) Lymph Node Pathology, pp. 172-180. , 4th edn., H. L. Ioachim and L. J. Medeiros (Eds.), Philadelphia: Lippincott Williams & WilkinsHasserjian, R.P., Chen, S., Perkins, S.L., Immunomodulator agent-related lymphoproliferative disorders (2009) Mod Pathol, 22, pp. 1532-1540Tokuc, G., Oktem, S., Genc, A., Nasopharyngeal lymphoid hyperplasia after therapy for childhood lymphomas (2006) Acta Oncol, 45, pp. 618-620Kojima, M., Murayama, K., Higuchi, K., Reactive lymphoid hyperplasia with giant follicles associated with post-therapeutic state of hematological malignancies: a report of six cases (2006) Leuk Lymphoma, 47, pp. 1404-1406Chen, Y.K., Su, C.T., Chi, K.H., Utility of 18F-FDG PET/CT uptake patterns in Waldeyer's ring for differentiating benign from malignant lesions in lateral pharyngeal recess of nasopharynx (2007) J Nucl Med, 48, pp. 8-14Metser, U., Even-Sapir, E., Increased (18) F-fluorodeoxyglucose uptake in benign, nonphysiologic lesions found on whole-body positron emission tomography/computed tomography (PET/CT): accumulated data from four years of experience with PET/CT (2007) Semin Nucl Med, 37, pp. 206-222Makis, W., Ciarallo, A., Lisbona, R., Plasmablastic lymphoma of the oral cavity in an HIV-positive patient: staging with 18F-FDG PET/CT (2011) Acta Radiol, 52, pp. 970-972Kalkanis, D., Kalkani, M., Gomes, H., Interesting image. FDG-PET/CT in primary large B-cell lymphoma of the hard palate (2010) Clin Nucl Med, 35, pp. 24-25Kyo, C., Kawaoka, Y., Kinoshita, K., Mantle cell lymphoma presenting with a tumor of the hard palate (2010) Intern Med, 49, pp. 1663-1666Blodgett, T.M., Fukui, M.B., Snyderman, C.H., Combined PET-CT in the head and neck: part 1. Physiologic, altered physiologic and artifactual FDG uptake (2005) Radiographics, 25, pp. 897-912Wong, W.L., Gibson, D., Sanghera, B., Evaluation of normal FDG uptake in palatine tonsil and its potential value for detecting occult head and neck cancers: a PET CT study (2007) Nucl Med Commun, 28, pp. 675-680Chung, J.H., Cho, K.J., Lee, S.S., Overexpression of Glut1 in lymphoid follicles correlates with false-positive (18) F-FDG PET results in lung cancer staging (2004) J Nucl Med, 45, pp. 999-1003Nakagawa, T., Yamada, M., Suzuki, Y., 18F-FDG uptake in reactive neck lymph nodes of oral cancer: relationship to lymphoid follicles (2008) J Nucl Med, 49, pp. 1053-1059Oguz, A., Karadeniz, C., Citak, E.C., Thymic and adenotonsillar enlargement after successful treatment of malignancies (2005) Pediatr Hematol Oncol, 22, pp. 423-435Wöhrer, S., Jaeger, U., Kletter, K., 18F-fluoro-deoxy-glucose positron emission tomography (18F-FDG-PET) visualizes follicular lymphoma irrespective of grading (2006) Ann Oncol, 17, pp. 780-784Good, D.J., Gascoyne, R.D., Atypical lymphoid hyperplasia mimicking lymphoma (2009) Hematol Oncol Clin North Am, 23, pp. 729-74