Mikiko Hashisako

Chronic Diffuse Lung Diseases

Abstract Chronic diffuse lung diseases involve a spectrum of nonneoplastic inflammatory conditions that affect the lung parenchyma. This chapter reviews the spectrum of disease including idiopathic interstitial pneumonias, pulmonary manifestations of systemic collagen vascular disease, diffuse eosinophilc lung disease, drug-associated lung disease, diffuse granulomatous lung disease, and a variety of miscellaneous diseases that defy classification. Individual entities are reviewed, followed by a section highlighting a practical approach to the four most common patterns of injury encountered in practice.

Pathology of Idiopathic Interstitial Pneumonias.

The updated classification of idiopathic interstitial pneumonias (IIPs) in 2013 by American Thoracic Society/European Respiratory Society included several important revisions to the categories described in the 2002 classification. In the updated classification, lymphoid interstitial pneumonia (LIP) was moved from major to rare IIPs, pleuroparenchymal fibroelastosis (PPFE) was newly included in the rare IIPs, acute fibrinous and organizing pneumonia (AFOP) and interstitial pneumonias with a bronchiolocentric distribution are recognized as rare histologic patterns, and unclassifiable IIP (UCIP) was classified as an IIP. However, recent reports indicate the areas of concern that may require further evaluation. Here, we describe the histopathologic features of the updated IIPs and their rare histologic patterns and also point out some of the issues to be considered in this context.

Breakdown of lung framework and an increase in pores of Kohn as initial events of emphysema and a cause of reduction in diffusing capacity

Purpose Pulmonary emphysema is the pathological prototype of chronic obstructive pulmonary disease and is also associated with other lung diseases. We considered that observation with different approaches may provide new insights for the pathogenesis of emphysema. Patients and methods We reviewed tissue blocks of the lungs of 25 cases with/without emphysema and applied a three-dimensional observation method to the blocks. Based on the three-dimensional characteristics of the alveolar structure, we considered one face of the alveolar polyhedron as a structural unit of alveoli and called it a framework unit (FU). We categorized FUs based on their morphological characteristics and counted their number to evaluate the destructive changes in alveoli. We also evaluated the number and the area of pores of Kohn in FUs. We performed linear regression analysis to estimate the effect of these data on pulmonary function tests. Results In multivariable regression analysis, a decrease in the number of FUs without an alveolar wall led to a significant decrease in the diffusing capacity of the lung for carbon monoxide (DLCO) and DLCO per unit alveolar volume, and an increase in the area of pores of Kohn had a significant effect on an increase in residual capacity. Conclusion A breakdown in the lung framework and an increase in pores of Kohn are associated with a decrease in DLCO and DLCO per unit alveolar volume with/without emphysema.

An autopsy case of bird-related chronic hypersensitivity pneumonitis presenting with repeated acute exacerbation

A 68-year-old woman was admitted to our hospital with a dry cough in 2010. Chest computed tomography showed the appearance of a nonspecific interstitial pneumonia (NSIP) pattern. Video-assisted thoracoscopic surgery (VATS) was performed, and the specimens prominently showed a usual interstitial pneumonia (UIP) pattern. She was diagnosed with bird-related chronic hypersensitivity pneumonitis (BRCHP) on the basis of the detection of antibodies to pigeon dropping extract in her serum and a history of using feather-filled duvets and indirect exposure to birds in her living environment. Even though she was treated with corticosteroids and immunosuppressants and recommended to avoid bird-related antigens, she had a progressive course with repeated acute exacerbation episodes and died of respiratory failure. The autopsy findings showed diffuse alveolar damage superimposed on UIP. Clinicians should be aware that BRCHP patients especially with histopathologically UIP pattern may experience acute exacerbation.

Pathology of Interstitial Pneumonia Associated with Hypothyroidism-Report of Three Cases

Recently, idiopathic pulmonary fibrosis (IPF) associated with hypothyroidism was proposed as a possible link showing worse prognosis than IPF. We have reviewed our archives of interstitial pneumonias (IPs) and examined pathologic and clinical features of IPs associated with hypothyroidism to understand its variations. Pathologically, two cases showed usual interstitial pneumonia pattern, and one case showed non-specific interstitial pneumonia pattern. Small airway disease was a common histological feature in all cases. Two cases showed association with flavor of connective tissue disease (CTD). Diagnoses by multidisciplinary discussion for the three cases were IPF, unclassifiable IP, and systemic sclerosis associated interstitial lung disease. Our cases indicated that IPs associated with hypothyroidism may show not only IPF but also other histological types and probable connection to CTD. Furthermore, these three cases did not fit with predicted prognosis by histological patterns.

Spread through Air Spaces Detected in Frozen Sections of Lung Adenocarcinoma is a Sign of Air Space Invasion: A Case Report

A 70-year-old non-smoking woman was found to have 23 mm sized lung adenocarcinoma. Intraoperative frozen sections were performed which confirmed the diagnosis of adenocarcinoma. Surgical material revealed presence of tumor nests spreading through airspaces (STAS) as far as 9 mm from the edge of the main tumor. Based on the presence of STAS, resection of the remaining left upper lobe was performed after the first operation, and no residual tumor or STAS was detected. A retrospective review of the frozen sections showed the presence of STAS. This report indicates that evaluation of STAS at the time of surgery may help improve the clinical course of a patient undergoing limited resection.