AB 32. Pulmonary nodular lympoid hyperplasia. Case report

Background: Nodular lymphoid hyperplasia is considered to represent a localized form of lymphoid hyperplasia, which presents as a discreet pulmonary mass or masses Median age of diagnosis are 65 years (range, 19-80 years). Chest X-ray and CT scan show an isolated mass (64%) or multiple nodules (36%). Hilar or mediastinal adenopathy may be present is some patients.
Patients and methods: We describe the case of nodular lymphoid hyperplasia in a 52 year-old woman who presented with pulmonary multiple nodules, bilateral and mediastinal adenopathy, apparent by chest X-ray and CT-scan. Open biopsy was performed from the upper and down lobe of the right lung and from the mediastinal lymph nodes. Macroscopic examination revealed small white nodules, measuring 0.3 to 0.7 cm in maximum diameter. The sections were examined with H+E and followed by immunohistochemical study.
Results: Histological examination revealed multiple well demarcated nodules consisting of aggregates of lymphoid follicles and sheets of interfollicular small lymphocytes and plasma cells. Lymphoepithelial lesions were absent. The immunohistochemical stains for lymphoid markers were consistent with a reactive process. Bcl-2 protein expression was absent in geminal centers, but presented in the mantle zone and interfollicular T-cells. Similar were the immunohistochemical findings of the lymph nodes study.
Conclusions: Nodular lymphoid hyperplasia is a benign lesion, although surgical excision is usually needed to allow correct diagnosis. The main entity in the differential diagnosis of nodular lymphoid hyperplasia is BALT lymphoma.