Pulmonary toxocariasis presenting as migratory pulmonary infiltrates and mediastinal lymphadenopathy: a case report and literature review.

backgroundPulmonary toxocariasis, caused by the nematode Toxocara canis or T. cati, is an underdiagnosed cause of eosinophilic lung disease with highly variable radiological presentation that often mimics malignancy or other eosinophilic conditions. CASE PRESENTATION: A 53-year-old female smoker presented with progressive dyspnea and cough. Initial chest CT revealed right lower lobe consolidation with mediastinal lymphadenopathy (station 4R with short-axis diameters 12 mm), raising concern for lung cancer. Bronchoscopy with EBUS-TBNA was non-diagnostic. The patient was empirically started on dexamethasone (8 mg daily, tapered over 3 months) for suspected organizing pneumonia. During steroid taper, her symptoms recurred with delayed emergence of peripheral eosinophilia (670/µL; initial absolute eosinophil count on presentation was 90/µL), elevated IgE (456 IU/mL), and serial CT scans demonstrating migratory pulmonary infiltrates involving the right lower, right middle, and left lower lobes. A history of raw beef liver consumption prompted serological testing, which confirmed Toxocara canis infection. Treatment with albendazole alone (400 mg twice daily for 14 days, without corticosteroids) resulted in complete clinical and radiological resolution. LITERATURE REVIEW: We searched PubMed and Scopus (January 2014 - February 2026) for English- and French-language case reports of pulmonary toxocariasis. Fourteen new cases were identified and analyzed alongside the 12 cases from Ranasuriya et al.'s [1] review. These 26 cases demonstrate marked radiologic heterogeneity: multiple bilateral nodules (50%), consolidations (23%), pleural effusion (27%), and migratory infiltrates (8%). Pleural effusion has emerged as a distinct manifestation in seven recent cases. Delayed eosinophilia occurred in 12% of cases. Immunocompromised states (including primary ciliary dyskinesia, hematologic malignancies, and immunosuppressive therapy) were present in 23% of cases and may predispose to atypical presentations.

conclusionPulmonary toxocariasis should be considered in patients with migratory infiltrates, unexplained eosinophilic pleural effusion, or lung nodules with eosinophilia. A meticulous dietary and exposure history is essential. Diagnosis is confirmed by serology, and patients respond well to albendazole therapy.