Non-Hodgkin Lymphoma Presenting With Pulmonary Hyalinizing Granuloma: A Rare Clinical Entity.

Pulmonary hyalinizing granuloma (PHG) is an unusual benign pulmonary disease with nonspecific symptoms and slow progression, characterized by solitary or multiple fibrosing nodules. A definitive diagnosis of PHG usually requires a wide excisional biopsy. Associations of PHG with lymphoproliferative disorders, such as Castleman's disease and lymphoma, have been described. PHG is considered a paraneoplastic manifestation of those diseases. Treatment in most cases comprises therapy of the underlying condition with or without the use of empirical corticosteroid therapy. We report a case of a 57-year-old Caucasian female, who presented initially with dyspnea, fatigue, dry mouth, difficulty swallowing, night sweats, weight loss, and recurrent sinusitis. A physical examination revealed hepatosplenomegaly with generalized lymphadenomegaly. Chest computed tomography showed bilateral diffuse nodular changes about 10 mm in diameter in the lung parenchyma. A needle biopsy of a lymph node confirmed the diagnosis of non-Hodgkin lymphoma and chemotherapy was started. Since the parenchymal lung lesions progressed and no definite diagnosis could be made on the basis of transbronchial biopsy, a right-sided video-assisted thoracoscopy with atypical resection of the abnormalities was performed. The findings were consistent with a diagnosis of pulmonary hyalinizing granuloma. Due to preserved pulmonary function, there was no indication for starting corticosteroid therapy. The purpose of this case report is to draw attention to the possibility of pulmonary hyalinizing granuloma as a differential diagnosis when multiple nodular lesions are observed in the lungs. Although PHG is a rare entity, due to its frequent association with underlying diseases and nonspecific presentation, a careful investigation should be performed. For a definite diagnosis, a surgical biopsy is required.