Lymphoid Interstitial Pneumonia (LIP) Revisited: A Critical Reappraisal of the Histologic Spectrum of "Radiologic" and "Pathologic" LIP in the Context of Diffuse Benign Lymphoid Proliferations of the Lung

Diagnostic Approach to Interstitial Lung Diseases Associated with Connective Tissue Diseases

Interstitial lung disorders are a group of respiratory diseases characterized by interstitial compartment infiltration, varying degrees of infiltration, and fibrosis, with or without small airway involvement. Although some are idiopathic (e.g., idiopathic pulmonary fibrosis, idiopathic interstitial pneumonias, and sarcoidosis), the great majority have an underlying etiology, such as systemic autoimmune rheumatic disease (SARD, also called Connective Tissue Diseases or CTD), inhalational exposure to organic matter, medications, and rarely, genetic disorders. This review focuses on diagnostic approaches in interstitial lung diseases associated with SARDs. To make an accurate diagnosis, a multidisciplinary, personalized approach is required, with input from various specialties, including pulmonary, rheumatology, radiology, and pathology, to reach a consensus. In a minority of patients, a definitive diagnosis cannot be established. Their clinical presentations and prognosis can be variable even within subsets of SARDs.

Granulomatous Lung Diseases: A Practical Approach and Review of Common Entities

Granulomas are frequently encountered by pathologists in all types of lung specimens and arise from diverse etiologies. They should always be reported as necrotizing or non-necrotizing, with microorganism stains performed to evaluate for infection. With attention to distribution, quality (poorly vs well-formed), associated features, and correlation with clinical, radiologic, and laboratory data, the differential diagnosis for granulomatous lung disease can usually be narrowed to a clinically helpful "short list." This review describes a practical approach to pulmonary granulomas and reviews the clinicopathological aspects of common entities, including infectious (mycobacteria, fungi) and noninfectious (hypersensitivity pneumonitis, sarcoid, and vasculitis) causes.

Multidisciplinary Approach to the Diagnosis of Idiopathic Interstitial Pneumonias: Focus on the Pathologist's Key Role

Idiopathic Interstitial Pneumonias (IIPs) are a heterogeneous group of the broader category of Interstitial Lung Diseases (ILDs), pathologically characterized by the distortion of lung parenchyma by interstitial inflammation and/or fibrosis. The American Thoracic Society (ATS)/European Respiratory Society (ERS) international multidisciplinary consensus classification of the IIPs was published in 2002 and then updated in 2013, with the authors emphasizing the need for a multidisciplinary approach to the diagnosis of IIPs. The histological evaluation of IIPs is challenging, and different types of IIPs are classically associated with specific histopathological patterns. However, morphological overlaps can be observed, and the same histopathological features can be seen in totally different clinical settings. Therefore, the pathologist's aim is to recognize the pathologic-morphologic pattern of disease in this clinical setting, and only after multi-disciplinary evaluation, if there is concordance between clinical and radiological findings, a definitive diagnosis of specific IIP can be established, allowing the optimal clinical-therapeutic management of the patient.

Effective treatment of inhaled corticosteroid and bronchodilator for "lymphocytic interstitial pneumonia" in primary Sjögren's syndrome

We present a case of an 86-year-old woman who visited our hospital with a one-year history of exertional dyspnea (modified medical research council dyspnea scale; mMRC grade 2). Despite the absence of any smoking or dust exposure history, multiple cystic lesions were apparent in both lungs on her CT scan. We suspected Sjögren's syndrome-associated lymphocytic interstitial pneumonia (LIP) due to her additional symptoms of dry mouth and eyes. Her respiratory function test showed a restrictive disorder with a forced vital capacity (FVC) of 1.23 L (70.3 % predicted), forced expiratory volume in 1 s (FEV1) of 0.88 L, and FEV1/FVC of 71.5 %. The flow-volume curve showed a downward convex, suggesting peripheral airway obstruction. We initiated a daily inhalation treatment regimen comprising vilanterol 25 μg and fluticasone furoate 200 μg. One month later, at the follow-up visit, the clinical diagnosis of Sjögren's syndrome with LIP was made by positive SS-A and SS-B antibodies in the initial blood work, a Saxon test that confirmed decreased salivary secretion, and a confirmed diagnosis of dry eyes by her ophthalmologist. We noted improvement in FVC of 1.45 L (+17.8 %) and FEV1 to 0.99 L (+12.5 %) in the subsequent respiratory function test, along with alleviation of her symptoms. The present case represents the first report of LIP treated exclusively with inhaled corticosteroids and bronchodilators, highlighting a potential therapeutic approach, particularly for elderly patients vulnerable to immunosuppressive therapies.