Amyloidosis secondary to intrapulmonary Castleman disease mimicking pulmonary hyalinizing granuloma-like clinical features: A rare case report

RATIONALE: Amyloidosis secondary to intrapulmonary Castleman disease (CD) is a rare benign disease diagnosed by histopathology. It seems to be associated with chronic inflammation, and large amounts of IL-6 produced in the germinal center of CD may enhance the production of precursor of amyloid. PATIENT CONCERNS: We reported a case of an 18-year-old woman presenting with dry cough and dyspnea on exertion for 6 months and detailed exams revealed multiple pulmonary nodules, positive antinuclear antibodies, hypocomplementemia, and thrombocytopenia. DIAGNOSES: A computed tomography-guided percutaneous lung biopsy revealed the histopathological features of pulmonary hyalinizing granuloma (PHG), but video-assisted pulmonary wedge resection for biopsy with immunohistochemical stains finally demonstrated a corrected diagnosis of intrapulmonary CD with secondary amyloidosis. INTERVENTIONS: The patient had received prednisone and Tacrolimus for 6 months. OUTCOMES: There was no significant improvement in pulmonary lesions or platelet level. Chemotherapy to CD was needed. LESSONS: Intrapulmonary CD should be considered in patients with multiple pulmonary nodules irresponsive to corticosteroid and diagnosis of PHG should be carefully considered based on small lung biopsy sample. The treatment of amyloidosis secondary to CD remains to be uncertain.