Introduction: Lymphoma and tuberculosis in several cases share similar clinical features that are
difficult to differentiate. Lymphadenopathy, fever, malaise, weight loss, and respiratory
symptoms are clinical features that could be found in both lymphoma and tuberculosis. Positron
Emission Tomography/Computed Tomography Fluorodeoxyglucose (F-18 FDG PET) is a pivotal
modality for imaging patients with cancer. Several non-malignant diseases like tuberculosis
infection show high FDG uptake and lead to low specificity of F-18 FDG PET.
Case Presentation: This case report describes a 55-year-old male patient with a history of Diffuse
Large B-cell Lymphoma (DLBCL) who was suspected of having a recurrent disease. The patient
has had a 6-month remission period after 6 cycles of R-CHOP regimen chemotherapy. He denied
any known history of tuberculosis infection and HIV. F-18 FDG PET was performed to assess the
extent of suspected lymphoma recurrent disease. F-18 FDG PET demonstrated multiple
hypermetabolic bilateral neck region, mediastinum, and bilateral axilla lymphadenopathies.
There were also multiple high FDG uptakes in the liver, mesocolon, and bones. The patient was
suspected of having a lymphoma recurrent disease based on these findings. He underwent an
excisional biopsy in the neck and was found to have lymphadenitis granulomatous disease from
tuberculosis. Based on the histopathology finding, the patient received anti-tuberculosis drugs
for 12 months and showed relief of signs and symptoms. F-18 FDG PET for anti-tuberculosis
treatment evaluation revealed a complete metabolic response.
Conclusion: Tuberculosis should be one of the differential diagnoses when a lymphoma recurrent
disease is suspected. Clinical features, laboratory results, and imaging findings sometimes show
similarities between lymphoma and tuberculosis. Histopathology evaluation is mandatory to
confirm the diagnosis