Chickenpox-related pulmonary granulomas in immunocompetent adults: clinicopathologic and molecular features of an underrated occurrence.

Pulmonary granulomas represent a common inflammatory reaction to several lung infective or noninfective diseases. However, little is known about the histology and clinical presentation of chickenpox-related granulomas in immunocompetent subjects. We collected a series of 8 adult patients (mean age, 40 y; range, 33 to 53 y) with several bilateral pulmonary granulomas incidentally discovered after imaging studies. All patients were asymptomatic and had experienced a varicella-zoster virus (VZV) infection as adults but were clinically suspected to have a metastatic neoplasm of unknown origin. Chest computed tomography scan revealed numerous, tiny (few millimeters to 1 cm in size) nodules randomly dispersed through the lungs. Positron emission tomography scan performed in 4 patients was negative. All patients underwent video-assisted thoracoscopic surgical resection and were still alive and well. At histology, granulomas consisted of well-defined, rounded, small nodules centered by a deeply eosinophilic, acellular necrosis rimmed by lamellar dense collagen and a chronic inflammatory infiltrate with or without multinucleated giant cells. Chickenpox-related granulomas were included in the differential diagnosis along with several other granulomatous diseases. Polymerase chain reaction-based molecular analysis for VZV performed on paraffin sections detected VZV DNA in all 8 cases. By contrast, 85 cases of pulmonary granulomas of different etiologies were simultaneously studied by molecular analysis with negative results. Pathologists should be familiar with the peculiar morphologic appearance of chickenpox-related granulomas. A careful search for a history of VZV infection in adulthood and molecular studies may be very helpful in confirming the diagnosis.

Tuberculosis unleashed: the impact of human immunodeficiency virus infection on the host granulomatous response to Mycobacterium tuberculosis.

The granuloma plays a critical role in the host immune response to Mycobacterium tuberculosis, containing the organism and confining it in a latent state in most infected individuals. Indeed, approximately one-third of the world's population has latent M. tuberculosis infection. However, over the past decade, the human immunodeficiency virus type 1 (HIV-1) pandemic has profoundly affected the incidence and clinicopathological features of tuberculosis. This review examines the immunological mechanisms whereby HIV-1 impairs the establishment, maintenance and function of the tuberculous granuloma.

Primary lymphoepithelioma-like carcinoma of the lung.

Primary lymphoepithelioma-like carcinoma (LELC) of the lung is a neoplasm seen most commonly in the nasopharynx of individuals from south China and Taiwan, and is strongly associated with the Epstein-Barr virus. The case of a 62-year-old Chinese man with a rare primary lung T2N1M0 LELC of the left lower lobe is presented. The lesion was further notable because of the presence of necrotizing granulomatous inflammation. The patient was treated with surgical resection. After it was determined that the neoplasm was of primary lung origin, adjunctive chemotherapy was initiated. The role of adjunctive chemotherapy in this setting is discussed.

[Lung and bone marrow granulomas associated with human parvovirus B19 infection].

A 56-year-old man was admitted with flu-like symptoms, and his platelet count abruptly decreased. A chest X-ray film showed granular shadows, and lung and bone marrow specimens disclosed non-caseating epithelioid cell granulomas. The patient's serum IgM titer for human parvovirus (HPV) B19 was elevated. Our conclusion was that HPV B19 must be kept in mind as a possible pathogenic agent of granuloma formation.

Viral infection modulates expression of hypersensitivity pneumonitis.

Hypersensitivity pneumonitis (HP) is a granulomatous, inflammatory lung disease caused by inhalation of organic Ags, most commonly thermophilic actinomycetes that cause farmer's lung disease. The early response to Ag is an increase in neutrophils in the lung, whereas the late response is a typical Th1-type granulomatous disease. Many patients who develop disease report a recent viral respiratory infection. These studies were undertaken to determine whether viruses can augment the inflammatory responses in HP. C57BL/6 mice were exposed to the thermophilic bacteria Saccharopolyspora rectivirgula (SR) for 3 consecutive days per wk for 3 wk. Some mice were exposed to SR at 2 wk after infection with respiratory syncytial virus (RSV), whereas others were exposed to SR after exposure to saline alone or to heat-inactivated RSV. SR-treated mice developed a typical, early neutrophil response and a late granulomatous inflammatory response. Up-regulation of IFN-gamma and IL-2 gene expression was also found during the late response. These responses were augmented by recent RSV infection but not by heat-inactivated RSV. Mice with a previous RSV infection also had a greater early neutrophil response to SR, with increased macrophage inflammatory protein-2 (MIP-2, murine equivalent of IL-8) release in bronchoalveolar lavage fluid. These studies suggest that viral infection can augment both the early and late inflammatory responses in HP.