[The clinicopathological analysis of pulmonary parenchymal involvement of multicentric giant lymph node hyperplasia (Castleman's disease)].

Objective: To observe the clinicopathological features of pulmonary parenchymal involvement of multicentric Castleman's disease(MCD).

Methods: Retrospective analysis was carried out for 6 patients of MCD with pulmonary parenchymal involvement who had been admitted to Peking Union Medical College Hospital from July 2008 to March 2013. Relevant literatures were reviewed. The diagnosis was established by surgical lung biopsy and all specimens were fixed in neutral formalin and embedded in paraffin. Sections were cut for HE and immunohistochemical stain. B cell and T cell gene rearrangement were tested in 3 cases.

Results: These 6 patients (all females) aged 31-68 years, with a median of 49.5 years. The presenting symptoms were fever (4/6), cough (3/6), and lymphadenopathy (6/6). Laboratory study showed elevated ESR (5/6) and CRP (4/6), and hypergammaglobulinaemia (2/6). Chest CT showed multiple nodules with perilymphatic distribution and ground-glass opacity (GGO). Pathologically, there were 5 cases of plasma cell type and 1 case of hyaline vascular type. The plasma cell variant showed dense mature plasma cell infiltration in pulmonary interstitium. The hyaline vascular variant was characterized by the presence of regressed germinal centers and broad concentric mantle zones. The gene arrangement tests were all negative. During the follow-up period (range: 2-60 months; mean: 31 months), 2 cases with plasma cell type received CHOP chemotherapy and then remained stable. One case with hyaline vascular type received CHOP chemotherapy but died due to deterioration of the disease.

Conclusions: In the thorax, Castleman's disease usually manifests as hilar and mediastinal lymph node enlargement. Pulmonary parenchymal involvement by MCD is very rare. It is mostly seen in the elderly female, and can manifest with systemic symptoms. Chest CT usually reveals multiple nodules and GGO. It shows similar morphological characteristics to those found in lymph nodes. Immunohistochemistry and gene rearrangement test can help to differentiate it from other pulmonary lymphoproliferative diseases.