INTRODUCTION: Primary tumors of the lung are rare in children and clinical manifestations can be nonspecific. We present the case of an adolescent female who was referred to a tertiary care medical center with persistent cough and left upper lobe density unresponsive to antibiotics. Her work up revealed an inflammatory pseudotumor which was treated successfully with steroid therapy.
CASE PRESENTATION: KB is a 17-year-old African-American female who presented with a three month history of persistent cough and an unresolving left upper lobe density. She had been treated with three courses of antibiotics unsuccessfully and was experiencing dyspnea on exertion, anorexia and weightloss. She had no history of fever and her chest was clear to auscultation but she was tachypneic. Review of systems, past and family history were unremarkable. She had no exposure to tuberculosis and was not engaged in high risk behavior. Her chest X-ray changes were stable. There was no evidence of oligemia of lung fields. She had a negative Mantoux test, negative sputum cultures, non-diagnostic angiotensin converting enzyme level, negative histoplasmosis titres, normal lactate dehydrogenase level and an elevated C- reactive protein (CRP) level. A chest computerized tomographic (CT) scan was performed which showed a granulomatous process involving the parenchyma of the left upper lobe extending into the mediastinum and encasing the left pulmonary artery. The lesion showed both fibrous and scattered small calcific elements. A ventilation and perfusion scan revealed compromised blood flow and ventilation to the left upper lobe of lung (Right/Left ratio of 93/07). A biopsy of the lesion showed fibroadipose tissue with chronic inflammatory infiltrate suggestive of inflammatory pseudotumor. The patient and family refused surgical treatment. She was thus treated with a three month course of oral cyclo-oxygenase-2 inhibitor (COX2I) anti-inflammatory agent with continued exertional dyspnea, cough and weightloss. The patient was then treated with a prolonged course of prednisolone over six months with involution of the tumor, decreasing CRP levels, improved left pulmonary arterial blood flow and symptomatic relief.
DISCUSSIONS: Inflammatory pseudotumor is believed to be the most common primary pulmonary childhood tumor, its etiology and pathogenesis remain obscure. Important differential diagnoses include granulomatous diseases such as tuberculosis, fungal infections and sarcoidosis as well as other neoplasms. The case highlights the importance of chest CT evaluation of suspicious lesions as it may better delineate the extent and nature of a lesion and in our case demonstrated unsuspected impressive pulmonary artery compression which had not been appreciated on Chest X-ray. While resection is usually curative, the close vascular relationship of the tumor and refusal for surgery were limitations to excision in our patient. Having reviewed non-surgical treatment options and their side-effects with the family, a decision to try COX2I was made, based on a case report; without success. Reports of use of steroid therapy for inflammatory pseudotumor are scarce and anecdotal however given the anatomical and treatment limitations in our patient with the progressive nature of the disease process this therapy was used successfully with significant anatomic and symptomatic improvement. Mild hypertension and Cushingism were the only significant side-effects of therapy.
CONCLUSION: Primary pulmonary tumors must be considered in the differential diagnosis of persistent respiratory symptoms in pediatric patients. Chest CT scan is useful for the evaluation of persistent lung lesions and should be resorted to without delay. While excision of inflammatory pseudotumor of lung is often definitive therapy, recurrences are known. Non-surgical treatment options are limited; steroids may be used when excision is not possible or limited in patients with inflammatory pseudotumor.
DISCLOSURE: Ameet Daftary, None.