Reactive Tonsillar Enlargement With Strong 18F-FDG Uptake After Chemotherapy for Tonsillar Diffuse Large B-cell Lymphoma

Abstract

We describe a 14-year-old boy who exhibited left palatine tonsillar enlargement after 6 cycles of aggressive chemotherapy for diffuse large B-cell lymphoma of the right palatine tonsil. The cervical computed tomography scan at 4 months after completion of chemotherapy revealed enlargement of the left palatine tonsil in addition to the thymus without any clinical symptoms. The F-fluorodeoxyglucose positron emission tomography indicated focal areas of strong F-fluorodeoxyglucose uptake in the left palatine tonsil. Histologic examination confirmed tonsillar hyperplasia with no evidence of recurrence. Reactive tonsillar hyperplasia after chemotherapy is rarely reported.

Reactive Tonsillar Enlargement Showing Strong 18F-Fdg Uptake During the Follow-Up of Follicular Lymphoma

“…To our knowledge, it is the second case of histologyproven RFH affecting the palatine tonsil with strong 18 F-FDG uptake [8] and we suggested that chemotherapy is probably related with this finding.…”

“…To the best of our knowledge, there is only one case of palatine tonsil RFH showing 18 F-FDG uptake in a 14-year-old boy after 6 cycles of aggressive chemotherapy for diffuse large B cell lymphoma [8]. It is interesting the fact that several RFH cases, usually affecting the tonsils, lymph nodes and thymus gland, in patients with hematological malignancies after chemotherapy have been reported [8,11,12,22]. In these cases, it is often difficult to distinguish RFH from residual or recurrent disease, even if various imaging modalities are used.…”

“…18 F-FDG accumulation in the major salivary glands, spinal cord, and vocal cords is variable; whereas in the inferior concha, thyroid gland, and tongue is typically minimal [4]. In lymphoma patients, unfortunately, false-positive results are possible, because an infection, inflammation, hypermetabolic brown fat surrounding lymph nodes or reactive process producing strong 18 F-FDG uptake might be present [2,[5][6][7][8]. In these cases, and not uncommonly after chemotherapy, reactive enlargement of the lymph nodes, tonsils, and thymus gland can be detected [8][9][10][11][12].…”

“…In lymphoma patients, unfortunately, false-positive results are possible, because an infection, inflammation, hypermetabolic brown fat surrounding lymph nodes or reactive process producing strong 18 F-FDG uptake might be present [2,[5][6][7][8]. In these cases, and not uncommonly after chemotherapy, reactive enlargement of the lymph nodes, tonsils, and thymus gland can be detected [8][9][10][11][12]. Thus, to accurately interpret FDG-PET/CT images, one must be fully familiar with the variable patterns and intensities of uptake and with the frequencies of physiologic and nonphysiologic uptake [13,14].…”

Degree of Association Between Fludeoxyglucose Uptake in Palatine Tonsils in Pet Scan and Histopathologic Examination in Follow Up Cases of Non-Hodgkin’s Lymphoma and Hodgkin’s Lymphoma

“…[4] In lymphoma patients, unfortunately, false-positive results are possible, because an infection, inflammation, hypermetabolic brown fat surrounding lymph nodes or reactive process producing strong 18F-FDG uptake might be present. [2,[5][6][7][8] In these cases, and not uncommonly after chemotherapy, reactive enlargement of the lymph nodes, tonsils, and thymus gland can be detected. [8][9][10]…”