Inflammatory pseudotumors of the lung: progression from organizing pneumonia to fibrous histiocytoma or to plasma cell granuloma in 32 cases.

https://www.annalsthoracicsurgery.org/article/S0003-4975(99)00155-1/pdf

Inflammatory pseudotumors of the lung

Twenty-seven pulmonary lesions have been reviewed both clinically and pathologically mainly by light microscopy. Almost all the lesions have shown features which were predominantly those associated with either a plasma cell granuloma or a histiocytoma. Both conditions arise from a common chronic inflammatory origin and form one disease complex. In almost every instance the lesions show some features characteristic of the other. In two malignant change had occurred. The light microscopic and electron microscopic characteristics of this complex of lung lesions are described. A possible aetiological cause is suggested. The many names that have been given to this group of pulmonary lesions in the past have led to confusion and failure to recognize their inflammatory nature.

The pulmonary plasma cell/histiocytoma complex

The term "inflammatory myofibrohistiocytic proliferation" (IMP) has been proposed to replace the conventional designations of plasma cell granuloma and inflammatory pseudotumor. Three cases of extrapulmonary IMP in children are reported, including an intracerebral lesion which has been formerly undescribed. In children, IMP may be associated with microcytic hypochromic anemia, hypergammaglobulinemia, and high erythrocyte sedimentation rate. In this clinical setting, differentiation of a rapidly growing but benign IMP from a bona fide sarcoma is of paramount importance.

Richard Buell

Papers

Endobronchial plasma cell granuloma (xanthomatous pseudotumor); a light and electron microscopic study.