Three distinct entities are now covered by the definition of primary pulmonary clonal lymphoid proliferation. The aim of this review is to describe the pathophysiological, diagnostic, prognostic and therapeutic aspects of these three entities.Low-grade pulmonary B-cell lymphoma is the most frequent form of primary pulmonary clonal lymphoid proliferation. It arises from mucosa-associated lymphoid tissue. It is usually indolent and appears in the form of a chronic alveolar opacity. The prognosis is excellent, but treatment is controversial (simple monitoring, surgery or single-agent chemotherapy). High-grade pulmonary B-cell lymphoma is far rarer and usually occurs in individuals with an underlying disorder (e.g.immunodeficiency). The prognosis is poor and therapeutic options depend on the underlying disorder.The inclusion of lymphomatoid granulomatosis in the definition of primary pulmonary lymphomas is controversial. The clonal nature of the proliferation is very rarely demonstrated and extrapulmonary involvement is frequent (upper airways, skin, kidneys, central nervous system,etc.). The prognosis is extremely variable, with some authors reporting complete remission with steroids and cyclophosphamide and others reporting failure of combination chemotherapy.

Immune checkpoint inhibitor-related pneumonitis (ICI-P) during cancer treatment is rarely observed (<5%). ICI-P is more often observed in patients with nonsmall cell lung cancer (NSCLC) than in those with other cancers. Likewise, it is more common in those receiving programmed cell death (PD)-1/PD-1 ligand inhibitors rather than cytotoxic T-lymphocyte antigen (CTLA)-4 inhibitors alone. The frequency of ICI-P is higher when anti-PD-1 and anti-CTLA-4 are administered concomitantly. Despite the low fatality rate (≈13%), ICI-P is the leading cause of ICI-related deaths. This narrative review focuses on the epidemiology, clinical and radiological presentation and prognosis of ICI-P occurring in patients, especially those with advanced NSCLC. Emphasis is placed on the differences in terms of frequency or clinical picture observed depending on whether the ICI is used as monotherapy or in combination with another ICI or chemotherapy. Other pulmonary complications observed in cancer patients, yet not necessarily immune-related, are reviewed, such as sarcoid-like granulomatosis, tuberculosis or other infections. A proposal for pragmatic management, including differential diagnosis and therapeutic strategies, is presented, based on the ICI-P series reported in the literature and published guidelines.

Pathogenic genetic variants (formerly called mutations) present in the germline of some individuals are associated with a clinically relevant increased risk of developing lung cancer. These germline pathogenic variants are hereditary and are transmitted in an autosomal dominant fashion. There are two major lung cancer susceptibility syndromes, and both seem to be specifically associated with the adenocarcinoma subtype. Li-Fraumeni syndrome is caused by variants in theTP53tumour-suppressor gene. Carriers are mainly at risk of early-onset breast cancer, sarcoma, glioma, leukaemia, adrenal cortical carcinoma and lung cancer.EGFRvariants, T790M in particular, cause theEGFRsusceptibility syndrome. Risk seems limited to lung cancer. Emerging data suggest that variants inATM, the breast and pancreatic cancer susceptibility gene, also increase lung adenocarcinoma risk. As for inherited lung disease, cancer risk is increased inSFTPA1andSFTPA2variant carriers independently of the underlying fibrosis. In this review, we provide criteria warranting the referral of a lung cancer patient to the cancer genetics clinic. Pathogenic variants are first identified in patients with cancer, and then in a subset of their relatives. Lung cancer screening should be offered to asymptomatic carriers, with thoracic magnetic resonance imaging at its core.

To analyze the impact of highly active antiretroviral therapy (HAART) on the characteristics and outcome of sarcoidosis in patients infected with human immunodeficiency virus (HIV), we identified HIV-infected patients in whom sarcoidosis was diagnosed between 1996 and 2000 from the admission registers of the pneumology departments of 12 hospitals in the Paris region (France). Sarcoidosis was diagnosed in 11 HIV-infected patients, of whom 8 were receiving HAART. HIV infection was diagnosed before sarcoidosis in 9 cases. At diagnosis of sarcoidosis, the mean CD4 cell count (±SD) was 390 ± 213 cells/mm³, and the mean plasma virus load was 4002 ± 10,183 copies/mL. Sarcoidosis occurred several months after HAART introduction, when the CD4 cell count had increased and the plasma HIV load had decreased. Clinical and radiological characteristics, laboratory values for bronchoalveolar lavage fluid samples, and outcome after a long follow-up were similar for the patients receiving HAART and for HIV-uninfected patients.

This general review sought to clarify the pathophysiological, diagnostic, prognostic, and therapeutic features of pulmonary mucosa-associated lymphoid tissue (MALT) lymphoma.MALT lymphoma is the most common pulmonary B-cell lymphoma, which usually occurs in the context of acquired MALT. The disease is slow-growing with an asymptomatic chronic alveolar opacity visible on radiography. Diagnosis requires tissue samples that should be retrieved using minimally invasive techniques, such as bronchoscopy or computed tomography-guided biopsies. The pathophysiology includes cytogenetic abnormalities and autoimmune diseases, whereas an association with a chronic pulmonary infection is still suspected but not yet demonstrated. Disease prognosis is typically excellent and the current available treatments are discussed in this review, including the decision not to treat, surgery, and single- or double-agent chemotherapy.