Case records of the Massachusetts General Hospital. Weekly clinicopathological exercises. Case 38-1977

Lymphoid interstitial pneumonia: clinicopathological and immunopathological findings in 18 cases

Eighteen patients with lymphoid interstitial pneumonia (LIP) were studied. The diagnosis was established by the microscopic finding of interstitial infiltrates of lymphocytes and plasma cells. Forty-seven% of patients also had germinal centres, while 72% showed interstitial giant cells. Cases studied by the immunoperoxidase technique showed the interstitial plasma cells to be polytypic. The median age of patients was 56 years; most had cough, dyspnea, or chest pain. Chest X-rays showed either patchy interstitial infiltrates (usually bilateral) or poorly defined nodules. Ten patients had hypergammaglobulinemia; one had hypogammaglobulinemia. Two patients had Sjögren's syndrome, two had biopsy-proven chronic active hepatitis, and two had a clinical diagnosis of primary biliary cirrhosis. Follow-up examination of 14 patients showed clearing of symptoms, X-ray infiltrates or stable infiltrates in 4 cases each. Five patients died (mean survival, 41 months), one of whom succumbed to disseminated lymphoma and a second to respiratory failure. Our results support the hypothesis that LIP is a non-neoplastic cellular proliferation in which lymphoma may supervene. The high incidence (22%) of chronic liver disease has not previously been noted.

Pulmonary lymphomas and other pulmonary lymphoid lesions. A clinicopathologic and immunologic study of 64 patients

Sixty-four patients with lymphoid lesions involving the lung were separated into three groups. In 32 patients, the predominant lymphoid cell population consisted of small, mature-appearing round lymphocytes with or without plasmacytoid features. This group, designated small lymphocytic proliferation (SLP), represents a heterogeneous group of pulmonary lymphocytic lesions including small lymphocytic lymphoma, lymphocytic interstitial pneumonia, and lymphoid hyperplasia (pseudolymphoma). Thirteen SLP patients were identified as having small lymphocytic lymphoma on the basis of monoclonality, progressive disease in other sites, or both. This group was morphologically identical to the remainder of the SLP patients, except for a higher incidence of plasmacytoid features (P = 0.003) and a greater degree of mast cell infiltration (P less than 0.05). Four of these 13 patients subsequently developed an aggressive large cell lymphoma resulting in death in three patients. The median survival for all of the SLP patients has not yet been reached. Patients in whom a monoclonal cell population could be established showed a slightly worse prognosis of borderline statistical significance (P = 0.09); however, the presence of a serum monoclonal gammopathy conveyed a significantly worse prognosis (P = 0.003). The remaining two groups of patients had various forms of malignant lymphoma other than the small lymphocytic type. One group of 12 patients, designated as having presumed primary lymphoma limited to one or both lungs (PL), had a prolonged course with a median survival of 117 months. The remaining 20 patients had disseminated lymphoma also involving lung (DL); DL patients had a shorter median survival of 33 months.

Lymphocytic interstitial pneumonia identified as lymphoma of mucosa associated lymphoid tissue

The widespread interstitial pulmonary infiltration in two patients, showing the clinical, radiological and histological features of lymphocytic interstitial pneumonia (LIP), has been characterized by histological and immunological criteria as malignant lymphoma of follicle centre cell (FCC) origin with plasmacytic differentiation. One patient also had malignant lymphoma of the parotid glands which had been present for many years and was previously considered benign (benign lymphoepithelial lesion). The other patient had a long history of Sjögrens syndrome. The lymphomas in these patients are presented as typical examples of malignant lymphoma of mucosa-associated lymphoid tissue.

Immunoblastic lymphoma arising in chronic lymphoid hyperplasia of the pulmonary interstitium

Chronic pulmonary lymphoid hyperplasia occurs alone or is associated with a variety of disorders of the immune system. It may be a diffuse or localized process and has been referred to as lymphoid interstitial pneumonitis or pseudolymphoma, respectively. Chronic lymphoid hyperplasia in other organs has been followed by the development of malignant lymphoma, particularly when associated with disorders of the immune system. This report describes two patients with chronic hyperplasia of the pulmonary interstitial lymphoid tissue who had malignant lymphoma, immunoblastic type found at autopsy. Long-term steroid usage in one patient suggests the possibility that immunosuppressive therapy may increase the risk of developing malignant lymphoma in patients with chronic pulmonary lymphoid hyperplasia.