Pulmonary Inflammatory Myofibroblastic Tumor in a Patient Treated for Pemphigus Vulgaris: A Case Report.

Inflammatory myofibroblastic tumors (IMTs) are benign tumors with diverse histological presentations. Pulmonary IMTs are particularly uncommon. Diagnosis often necessitates surgical intervention for both therapeutic and diagnostic purposes. We report the case of a 70-year-old woman with a history of uncontrolled asthma and pemphigus vulgaris treated with rituximab and corticosteroids. She presented with chest pain and a dry cough, without systemic symptoms. Imaging revealed a solitary pulmonary nodule. Thoracoscopic resection confirmed the diagnosis of an IMT, characterized histologically by spindle cell proliferation and inflammatory infiltrates, with negative anaplastic lymphoma kinase (ALK) expression. Pulmonary IMTs are rare and diagnostically challenging due to their overlapping features with other pulmonary lesions. Etiologies include infections, autoimmune conditions, and chromosomal abnormalities, with a potential link to IgG4 involvement in allergic and autoimmune contexts. Radiologically, they typically present as well-circumscribed solitary nodules. Definitive diagnosis often necessitates surgical excision, given the limitations of imaging and biopsy. Pulmonary IMTs, while benign, require prompt diagnosis and management due to their potential for local recurrence and rare malignant transformation. Surgical resection remains the cornerstone of treatment, underscoring the importance of vigilant long-term follow-up.