Manifestation of severe pneumonia in anti-PL-7 antisynthetase syndrome and B cell lymphoma: A case report

BACKGROUND: Antisynthetase syndrome (ASS) is characterized by the presence of antisynthetase antibodies coupled with clinical findings such as fever, polymyositis-dermatomyositis and interstitial lung disease. It is, however, rare to observe ASS association with B cell lymphoma presenting severe pneumonia as the first clinical manifestation. CASE SUMMARY: We evaluated a 59-year-old male patient who presented with cough with sputum, shortness of breath and fever for 13 d. A chest computed tomography radiograph revealed bilateral diffuse ground-glass infiltrates in both upper fields, left lingual lobe and right middle lobe. Initially, the patient was diagnosed with severe community-acquired pneumonia and respiratory failure. He was empirically treated with broad-spectrum antibiotics, without improvement. Further analysis showed an ASS panel with anti-PL7 antibodies. Besides, electromyography evaluation demonstrated a manifestation of myogenic damage, while deltoid muscle biopsy showed irregular muscle fiber bundles especially abnormal lymphocyte infiltration. In addition, bone marrow biopsy revealed high invasive B cell lymphoma. Thus, the patient was diagnosed with a relatively rare anti–PL7 antibody positive ASS associated with B cell lymphoma. CONCLUSION: This case highlights that rapidly progressive lung lesions and acute hypoxemic respiratory failure associated with heliotrope rash and extremely high lactate dehydrogenase level should be considered as the characteristics of non-infectious diseases, especially ASS and B cell lymphoma.