Clinical features of non-Hodgkin's lymphoma in cheek misdiagnosed as inflammatory myopathy / 中华全科医师杂志

ABSTRACT

Objective To assess the clinical features of non-Hodgkin's lymphoma in cheek misdiagnosed as inflammatory myopathy.Methods Six patients presenting with unilateral swollen cheek were admitted at the Department of General Internal Medicine,Peking Union Medical College Hospital between January 2010 and December 2014.These patients were misdiagnosed as inflammatory myopathy and finally confirmed as Non-Hodgkin's lymphoma.The clinical characteristics,findings of laboratory tests and the diagnostic procedures were retrospectively analyzed.Results The median age of 6 patients (3 males and 3 females) was 30 years.The median duration from onset of unilateral swollen cheek to the final diagnosis was 13 months;the patients were referred to average 4 hospitals and experienced average 3 biopsies before admission.All patients had been treated with prednisone at a dose of 1 mg/kg or 0.5mg/kg per day.However,the symptoms relapsed in all patients after glucocorticoid tapering.No patient presented with proximal muscle weakness or myalgia.Two of 6 patients presented with unilateral forearm swollen.Creatine kinase was mildly elevated in 3 patients.Electromyographic abnormalities were seen in 4 patients.The biopsy showed muscle fiber necrosis,degeneration and a large amount of lymphocytes infiltration with or without vessel wall involvement.Erythrocyte sedimentation rate and high-sensitive C-reactive protein levels were normal.Anti-Jo-1,ANA and anti-U1RNP were all negative.EBV-DNV was significantly elevated in peripheral blood in 5 patients and it was positive in biopsy specimen in 3 patients.PET-CT scan was performed in 3 patients and suggested high metabolic activity with a SUV of 2.0-8.5 in cheek region.The biopsy specimen taken before admission did not show evidence of lymphoma.Repeated biopsies from cheek regions (3/6),lips (2/6) and forearm confirmed the final diagnosis as Non-Hodgkin's lymphoma,including 2 cases of T-cell lymphoma and 4 cases of NK/T cell lymphoma.Conclusion When patients present with unilateral swollen cheek without proximal skeletal muscle weakness or myalgia,even the pathologic evaluation implies inflammatory myopathy,non-Hodgkin's lymphoma should be considered.Repeated biopsy may be necessary to confirm the diagnosis.