Dados do Trabalho

Título

18F-FDG PET/CT in antisynthetase syndrome: Case Report

Introdução/Justificativa

Antisynthetase syndrome is an autoimmune pathology characterized by production of
autoantibodies against aminoacyl tRNA synthetase, mainly anti-Jo-1.

Relato

Male patient presenting a clinical picture of polyarthritis in hands and wrists, periorbital
edema, myositis and interstitial lung disease. FAN 1/320 (nuclear homogeneous), reactive
anti Jo-1, elevated CPK, erythrocyte sedimentation rate and CRP. MRI presenting muscle
edema, electroneuromyography compatible with myopathy and chest CT scan suggesting
inflammatory/infectious pattern. Patient was diagnosed with antisynthetase syndrome and
prednisone introduced. Later on course cyclophosphamide was added due to lung
involvement.
He evolved with respiratory and joint symptom improvement but with progressive worsening
of muscle symptoms, characterized by proximal weakness (difficulty getting out of bed and
car, daily life activities like brushing his teeths and eating). He also presented CPK rise,
persistent subfebrile temperature and signs of inflammatory activity (leukocytosis and CRP
rise), without any apparent focus and isolated episodes of dysphagia. Rituximabe was
introduced and PET/CT scan was performed to search for the focus of the infection.
PET/CT showed a diffuse pattern of muscle hypermetabolism, specially in right lower limb,
suggesting a diffuse muscle inflammation without any infectious focus.

Conclusão

Antisynthetase syndrome is a rare entity with few PET/CT reports in the literature. However
PET scan appears to be very useful in the investigation of fever of unknown origin,
diagnosing inflammatory activity and in response assessment evaluation.

Palavras Chave

Antisynthetase syndrome; 18F-FDG PET/CT; case report