Lymphoma and tuberculosis: temporal evolution of dual pathology on sequential 18F-FDG PET/CT

Foreign Body Granuloma Masquerading as Remnant Lymphoma on 18F-FDG PET/CT

ABSTRACT

A 54-year-old man complained of a growing nodule in the left upper arm, which was diagnosed as diffuse large B-cell lymphoma by postsurgical pathology. For baseline assessment, FDG PET/CT revealed intense uptake in the left upper arm, in addition to FDG-avid pleura lesions and regional, axillary, cervical, and mediastinal lymph nodes. After chemotherapy, the restaging scan showed complete remission of most involved lesions except for increased activity in the prior surgical site. The patient eventually underwent surgical resection again, and the diagnosis was confirmed as foreign body granuloma.

Hodkgin lymphoma concomitant of tuberculosis, a therapeutic challenge for multidisciplinary management

Hodgkin lymphoma (HL) is a disease characterized by a high curability rate, and the treatment benefit-risk balance must be carefully addressed to achieve complete disease control with low risk of long-term toxicities. Most patients are treated with a combination of chemotherapy and radiotherapy, after disease staging and response to treatment evaluated by FDG PET/CT. We report the case of a 28-year-old patient concomitantly diagnosed of a Hodgkin lymphoma and active tuberculosis. Initial staging was difficult due to pulmonary and abdominal tuberculosis localization that induced FDG PET/CT hypermetabolism. Anti-tuberculosis treatment was first started, allowing secondary an early accurate Hodgkin lymphoma staging by FDG PET/CT. The patient was then treated by chemotherapy and radiotherapy. Helical TomoTherapy® was used with involved site (IS) irradiation volume was performed to decrease the high doses to organs-at-risk (OAR), especially lungs in this context of tuberculosis.

Tubercular Meningitis and Lymphadenitis Mimicking a Relapse of Burkitt's Lymphoma on (18)F-FDG-PET/CT: A Case Report

Tuberculosis (TB) can present with various forms and can occasionally be mistaken for malignancy. Hereby, we report a 53-year-old man diagnosed and treated for Burkitt's lymphoma in 2009 who achieved a complete remission confirmed by a computed tomography (CT) scan. During the follow-up 2 years later, he complained of left hip pain that warranted investigation with magnetic resonance imaging and whole-body ¹⁸F-fludeoxyglucose-positron emission tomography (FDG-PET)/CT which showed a benign lesion in the left hip associated with multiple lymph nodes in the chest and abdomen not amenable for biopsy. A follow-up PET/CT scan a few months later showed intense tracer uptake in the lymph nodes with size progression and appearance of new lymph nodes suspicious of lymphoma relapse. The patient was asymptomatic, and all investigations including viral and connective tissue disease studies were negative. Also the tuberculin skin test and QuantiFERON were negative. Lymph node biopsy was planned; however, the patient presented a few days earlier with fever, headache and photophobia. Cerebrospinal fluid (CSF) examination confirmed meningitis with lymphocytic pleocytosis and elevated protein. The CSF Gram stain, culture, viral and acid-fast bacilli were negative. CSF flow cytometry and cytopathology confirmed polyclonal lymphocytosis and suggested reactive causes. CSF TB culture grew Mycobacterium tuberculosis. Mediastinal lymph node biopsy also confirmed TB lymphadenitis. Four antituberculosis drugs were started. One year later, a PET/CT scan showed regression of all the involved lymph nodes. This case highlights the importance of excluding TB in patients with suspected malignancy, especially if they belong to endemic regions, and the increasing role of ¹⁸F-FDG-PET/CT in the early detection of extrapulmonary TB.