Citations

Context.— Vaping is the inhalation of heated aerosol from a small battery-powered device as a method to deliver nicotine or other substances. A recent outbreak of severe respiratory illness primarily in the United States has put a spotlight on vaping and its potential risks. Objective.— To familiarize pathologists with vaping, the cytologic and histopathologic features of vaping-associated acute lung injury, and the role of pathology in this diagnosis. Data Sources.— A targeted literature review was performed. Conclusions.— Most cases of vaping-associated lung injury have been linked to vaping products containing tetrahydrocannabinol or other cannabinoids. Lung biopsies show a spectrum of nonspecific acute lung injury patterns (organizing pneumonia, diffuse alveolar damage, acute fibrinous, and organizing pneumonia, or combinations of the above), accompanied by prominent, foamy macrophage accumulation. Injury is usually accentuated around small airways. Lipid-laden macrophages can be identified in bronchioloalveolar lavage fluid in most patients and these can be highlighted using lipid stains, such as oil red O, but the clinical utility of this finding remains unclear, as lipid-laden macrophages can be seen in a wide variety of processes and should not be relied upon to make the diagnosis. Classic histologic features of exogenous lipoid pneumonia have not been identified in tissue samples. Lightly pigmented macrophages, similar to those seen with traditional cigarette smoking, are present in some cases but are usually a minor feature. To date, no specific pathologic features for vaping-related injury have been identified, and it remains a diagnosis of exclusion that requires clinicopathologic correlation.

Background: Steatotic grafts are increasingly being used for liver transplant (LT); however, the impact of graft steatosis on renal function has not been well described. Methods: A total of 511 allografts from Mayo Clinic Arizona and Minnesota were assessed. We evaluated post-LT acute kidney injury (AKI) patterns, perioperative variables and one-year outcomes for patients receiving moderately steatotic allografts (>30% macrovesicular steatosis, n = 40) and compared them to non-steatotic graft recipients. Results: Post-LT AKI occurred in 52.5% of steatotic graft recipients versus 16.7% in non-steatotic recipients (p < 0.001). Ten percent of steatotic graft recipients required new dialysis post-LT (p = 0.003). At five years, there were no differences for AKI vs. no AKI patient survival (HR 0.95, 95% CI 0.08–10.6, p = 0.95) or allograft survival (HR 1.73, 95% CI 0.23–13.23, p = 0.59) for those using steatotic grafts. Lipopeliosis on biopsy was common in those who developed AKI (61.0% vs. 31.6%, p = 0.04), particularly when the Model for End-Stage Liver Disease (MELD) was ≥20 (88.9%; p = 0.04). Lipopeliosis was a predictor of post-LT AKI (OR 6.0, 95% CI 1.1–34.6, p = 0.04). Conclusion: One-year outcomes for moderately steatotic grafts are satisfactory; however, a higher percentage of post-LT AKI and initiation of dialysis can be expected. Presence of lipopeliosis on biopsy appears to be predictive of post-LT AKI.

Common variable immunodeficiency (CVID) and selective immunoglobulin A deficiency (IgAD) often cause chronic lung disease, but the pulmonary pathologic features of these systemic diseases are poorly recognized by pathologists. It has been claimed that CVID cases show a characteristic combination of noncaseating granulomas-lymphoid proliferations termed granulomatous-lymphocytic interstitial lung disease (GLILD). We present 34 surgical lung biopsy cases of CVID and 4 of IgAD. Noncaseating granulomas were seen in 23/34 (68%) CVID and 2/4 (50%) IgAD cases. A statistically identical pattern of benign lymphoid proliferation was found in CVID and IgAD whether or not granulomas were present. Organizing pneumonia, sometimes considered a part of GLILD, was seen in 25/34 (74%) CVID and 2/4 (50%) IgAD cases and did not correlate with the presence of granulomas. On follow-up, 3 CVID patients died (only 1 of pulmonary disease), while 21 others are alive at 1 to 300 months with no difference by presence or absence of granulomas. Three IgAD patients with follow-up are alive. We conclude that CVID and IgAD are indistinguishable in surgical lung biopsies and a subset of both show patterns that would qualify as GLILD, while other cases lack granulomas but have identical patterns of lymphoid infiltration and organizing pneumonia. We suggest that GLILD is neither a specific nor a useful entity, and biopsies from CVID and IgAD patients should be diagnosed simply by microscopic pattern(s) observed. The prognosis of CVID with lymphoid infiltrates with or without granulomas in this series was good, contrary to claims in the literature about GLILD.

Background. Kidneys from deceased donors with acute kidney injury (AKI) are more likely to be discarded because of concerns for poor outcomes after transplantation. The aim of this study was to determine the long-term outcomes of a large cohort of patients transplanted utilizing kidneys from deceased donors with AKI. Methods. All patients receiving a deceased donor kidney transplant during a recent 10-year period were included. Acute Kidney Injury Network (AKIN) criteria were used to classify the donors. Donor kidneys with >10% cortical necrosis or more than mild chronic changes were discarded. The primary outcome is the combined endpoint of death or graft loss. Results. The cohort included 1313 kidneys from 974 donors, AKIN stage 0 (no AKI) in 319 (24.3%), stage 1 in 370 (28.2%), stage 2 in 177 (13.5), and stage 3 in 447 (34.0%). Estimated 5-year graft survival (95% confidence interval) was 78.5% (72.5-84.5), 77.8% (72.8-82.1), 83.8% (76.8-88.9), and 84.6% (79.5-88.7) for AKIN donor stage 0 to 3, respectively (log-rank P = 0.10). After adjusting for baseline differences, the hazard ratio (95% confidence interval) for the combined endpoint for the AKIN stage 3 group (relative to AKIN 0 group) was 0.70 (0.45-1.10). Delayed graft function occurred in 44.6% and 75.4% of AKIN 2 and 3 groups, as compared to 33.9% and 33.5% in AKIN 0 and 1 ( P < 0.001). Conclusion. We conclude that transplanting selected kidneys from deceased donors with AKI with preimplantation biopsy showing <10% cortical necrosis and no more than mild chronic changes have excellent long-term graft survival.

AimErdheim–Chester disease represents a clonal systemic proliferation of histiocytes. Bone is the most common site of involvement, although almost any organ, including the lungs, can be affected.Methods and resultsThe diagnosis of Erdheim–Chester disease can be difficult, owing to its rarity and protean presentation. Correlation between clinical, radiological and histological findings is mandatory for identification of the disease. Foamy histiocytes, lacking Langerhans cell markers, represent the typical histological findings, although their absence does not rule out Erdheim–Chester disease. Identification of BRAF mutation can be helpful in making the diagnosis, and allows for the development and application of targeted therapies in this setting.ConclusionsHerein, we describe two cases presenting with lung involvement and vertebral lesions, lacking the more typical long‐bone involvement. One case histologically mimicked Rosai–Dorfman disease. However, both cases harboured the pathognomonic BRAFV600E mutation.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) remains a poorly understood clinical entity. It is currently classified as a premalignant condition by the World Health Organization (WHO). Symptoms are similar to those associated with obstructive lung disease, including breathlessness and cough. The presentation is often initially ascribed to other diseases such as asthma or chronic obstructive pulmonary disease. Here, we present what we believe is the first described case of DIPNECH diagnosed by transbronchoscopic cryoprobe biopsy. The patient presented with chronic cough, dyspnoea, pulmonary function tests consistent with obstruction, and a computed tomography (CT) scan of chest with multiple nodules. The patient went on to have transbronchoscopic cryoprobe biopsies of the lung, which confirmed the diagnosis of DIPNECH.