An Adult Ascaris Worm Entrapped in a Pulmonary Tuberculous Cavity.

Abstract

To the Editors: Ascaris larvae have a pulmonary migration phase, during which they can cause pulmonary symptoms.1,2 We present a child with tuberculous pulmonary cavity consolidation in which an adult Ascaris worm was entrapped. A 9-year-old boy presented with mild fever for 10 days without cough or breathlessness. There was no history of passing any worms in stool, vomiting or abdominal pain. His vital signs were normal, and weight was below the fifth percentile (15 kg). Respiratory system examination was normal. The chest radiograph showed paracardiac opacity in the mid zone of the left lung. Computed tomography scan showed a left-sided paracardiac lung mass with breakdown (cavity consolidation) and pretracheal calcified granulomas consistent with tuberculosis. Computed tomography-scan–guided biopsy of the lung lesion revealed dense inflammation with a cross-section of parasite showing chitinous wall and inner muscular layer of an adult Ascaris worm (Fig. 1A and B). The erythrocyte sedimentation rate was 54 mm at first hour. Mantoux test and gastric lavages for acid-fast bacilli were negative. Stool examinations for parasitic ova were negative. Ultrasonography of the abdomen showed few preaortic and paraaortic lymph nodes (largest 1.2 cm × 0.8 cm). Mycobacterial DNA polymerase chain reaction from the lung biopsy sample was positive for Mycobacterium tuberculosis complex.FIGURE 1: Cross-sections of the parasite embedded in inflammatory exudate and hemorrhage (HE, ×40; A) and chitinous wall of Ascaris lumbricoides showing the inner muscular layer (HE, × 400; B).Initially, the consolidation was treated with intravenous amoxicillin–clavulanate for 7 days. Subsequently (after tuberculosis was confirmed), antituberculous therapy (4 drugs: isoniazid, rifampicin, pyrazinamide and ethambutol for 2 months followed by 2 drugs: isoniazid and rifampicin for 4 months) was given. Oral albendazole was administered. Repeat chest radiograph after 3 weeks of antituberculous therapy showed resolving lung opacity. The patient completed antituberculous therapy and was asymptomatic at 6 months. An adult Ascaris worm found entrapped in a tuberculous pulmonary cavity consolidation has not been reported previously. In our case, we postulate that either (i) an Ascaris larva during its pulmonary migration phase got trapped in the tuberculous cavity consolidation and subsequently matured into an Ascaris adult worm in situ or (ii) a mature Ascaris worm from the upper gastrointestinal tract was aspirated and reached the tuberculous pulmonary cavity consolidation and became trapped. Other cases of pulmonary involvement in ascariasis including eosinophilic pneumonia, fatal pulmonary gangrene with empyema, worm emerging through an intercostal chest tube, pulmonary ascariasis (dyspnea, nonproductive cough, fever and eosinophilia) and airway obstruction because of worm migration have been reported.3 Ectopic wanderers are adult worms that reverse direction of migration from the upper gastrointestinal tract to the pharynx (in debilitating illness, during anaesthesia or with use of partial ascaricidal drugs like tetrachloroethylene).3 Baar and Galindo4 have described a case of ossifying pulmonary granulomata with presence of larvae of Ascaris lumbricoides within the granulomata demonstrated by immunofluorescence (in an adult patient at autopsy). Chaudhry et al5 have reported a case similar to ours with a solitary pulmonary nodule in an asymptomatic 60-year-old adult male where the segmentectomy showed granuloma harboring an adult Schistosoma worm. Milind S. Tullu, MD Sunil Karande, MD Pragati A. Sathe, MD Department of Pediatrics and Pathology Seth G.S. Medical College & KEM Hospital Mumbai, Maharashtra, India