Pulmonary adenofibroma: clinicopathological study of 3 cases of a rare benign lung lesion and review of the literature.

Pulmonary adenofibroma is a rare benign biphasic tumor of the lung composed of epithelial and stromal components. We report 3 cases of this unusual lesion of lung in a male (25 years old) and 2 female (40 and 55 years old) patients. Breathlessness on exertion and mild left-sided chest pain of 1 month's duration were the main concerns in 2 patients, whereas the third had cough and hemoptysis for 3 months. Chest radiograph and computed tomography scan revealed a well-circumscribed, subpleural homogenous mass in left lower chest fields in 2 cases and solid-cystic lesion in left upper lobe in the third patient. All 3 patients underwent lobectomy, following biopsy in 2 cases. Histology revealed a well-circumscribed lesion composed of complex glandlike spaces lined by cuboidal to columnar epithelium surrounded by a hyalinized spindle-cell fibroblastic proliferation reminiscent of adenofibroma of the female genital tract or fibroadenoma of the breast. Immunohistochemical examination supported the diagnosis of a benign pulmonary adenofibroma. All 3 patients were are alive and doing well with no evidence of recurrent or metastatic disease. Diagnosis on biopsy can be challenging and may be misinterpreted as well-differentiated adenocarcinoma with extensive fibrosis or low-grade sarcoma. Frozen-section consultation will be a valuable adjunct in planning for limited lung resection of this benign lung lesion. Although we described 3 cases of pulmonary adenofibroma, still this is the largest published series of this rare entity till date. The possible histogenesis and various differential diagnoses are discussed along with literature review.