Faculty Bibliography

BACKGROUND:With the high prevalence of COVID-19 infections worldwide, the multisystem inflammatory syndrome in adults (MIS-A) is becoming an increasingly recognized entity. This syndrome presents in patients several weeks after infection with COVID-19 and is associated with thrombosis, elevated inflammatory markers, hemodynamic compromise and cardiac dysfunction. Treatment is often with steroids and intravenous immunoglobulin (IVIg). The pathologic basis of myocardial injury in MIS-A, however, is not well characterized. In our case report, we obtained endomyocardial biopsy that revealed a pattern of myocardial injury similar to that found in COVID-19 cardiac specimens. CASE PRESENTATION:A 26-year-old male presented with fevers, chills, headache, nausea, vomiting, and diarrhea 5 weeks after his COVID-19 infection. His SARS-CoV-2 PCR was negative and IgG was positive, consistent with prior infection. He was found to be in cardiogenic shock with biventricular failure, requiring inotropes and diuretics. Given concern for acute fulminant myocarditis, an endomyocardial biopsy (EMB) was performed, showing an inflammatory infiltrate consisting predominantly of interstitial macrophages with scant T lymphocytes. The histologic pattern was similar to that of cardiac specimens from COVID-19 patients, helping rule out myocarditis as the prevailing diagnosis. His case was complicated by persistent hypoxemia, and a computed tomography scan revealed pulmonary emboli. He received IVIg, steroids, and anticoagulation with rapid recovery of biventricular function. CONCLUSIONS:MIS-A should be considered as the diagnosis in patients presenting several weeks after COVID-19 infection with severe inflammation and multi-organ involvement. In our case, EMB facilitated identification of MIS-A and guided therapy. The patient's biventricular function recovered with IVIg and steroids.

PURPOSE/UNASSIGNED:Acute thromboembolic disease of the innominate artery (IA) poses a unique set of therapeutic challenges, owing to its contribution to both the cerebral and upper extremity circulation, and risks of distal embolization via the carotid and subclavian arteries, respectively. Herein, we present a 74-year-old female who presents with acute IA thrombus treated successfully with right axillary and common carotid exposure and aspiration catheter-directed mechanical thrombectomy (CDT). Furthermore, an emerging use of CDT and its application in acute thromboembolism are outlined. CASE REPORT/UNASSIGNED:A 74-year-old female with history of right lung transplant for pulmonary fibrosis with severe pulmonary hypertension, and stage IIIA left lung adenocarcinoma status post left lower lobectomy undergoing adjuvant chemotherapy presented with acute IA thrombus and right-sided stroke. She was treated successfully with right axillary and common carotid exposure and aspiration CDT. Computed tomography angiography performed 1 month postoperatively confirmed patent IA with no evidence of residual or recurrent thrombus. CONCLUSION/UNASSIGNED:There are currently no standard guidelines on the management of acute IA thromboembolism, with mostly individual cases reported in the literature describing this rare entity. Nevertheless, this unique clinical entity mandates expeditious diagnostic and therapeutic approaches in order to avoid permanent neurologic deficits from distal embolization. Our case demonstrates that aspiration CDT may be an effective treatment modality for patients with acute IA thrombus.

Cullin 4A and 4B ubiquitin ligases are often highly accumulated in human malignancies, and are believed to possess oncogenic properties. However, the underlying mechanisms by which CUL4A and CUL4B promote pulmonary tumorigenesis remain largely elusive. In this study, we report that both CUL4A and CUL4B are highly expressed in non-small cell lung cancer (NSCLC) patients, and high expression of both is associated with disease progression, chemotherapy resistance, and poor survival in adenocarcinomas. Depletion of CUL4A (CUL4A^k/d) or CUL4B (CUL4B^k/d) leads to cell cycle arrest at G1 and loss of proliferation and viability of NSCLC cells both in culture and in a lung cancer xenograft model, suggesting that CUL4A and 4B are oncoproteins required for tumor maintenance of certain NSCLC. Mechanistically, increased accumulation of the cell cycle-dependent kinase inhibitor p21/Cip1/WAF1 was observed in lung cancer cells upon CUL4 silencing. Knockdown of p21 rescued the G1 arrest of CUL4A^k/d or CUL4B^k/d NSCLC cells and allowed proliferation to resume. These findings reveal that p21 is the primary downstream effector of lung adenocarcinoma dependence on CUL4, highlight the notion that not all substrates respond equally to abrogation of the CUL4 ubiquitin ligase in NSCLCs, and imply that CUL4A^high CUL4B^high may serve as a prognostic marker and therapeutic target for NSCLC patients.

Lung transplant is increasingly performed for the treatment of end-stage lung disease. As the number of lung transplants and transplant centers continues to rise, radiologists will more frequently participate in the care of patients undergoing lung transplant, both before and after transplant. Potential donors and recipients undergo chest radiography and CT as part of their pretransplant assessment to evaluate for contraindications to transplant and to aid in surgical planning. After transplant, recipients undergo imaging during the postoperative hospitalization and also in the long-term outpatient setting. Radiologists encounter a wide variety of conditions leading to end-stage lung disease and a myriad of posttransplant complications, some of which are unique to lung transplantation. Familiarity with these pathologic conditions, including their imaging findings and their temporal relationship to the transplant, is crucial to accurate radiologic interpretation. Knowledge of the surgical techniques and expected postoperative appearance prevents confusing normal posttransplant imaging findings with complications. A basic understanding of the indications, contraindications, and surgical considerations of lung transplant aids in imaging interpretation and protocoling and also facilitates communication between radiologists and transplant physicians. Despite medical and surgical advances over the past several decades, lung transplant recipients currently have an average posttransplant life expectancy of only 6.7 years. As members of the transplant team, radiologists can help maximize patient survival and hopefully increase posttransplant life expectancy and quality of life in the coming decades. ^©RSNA, 2021 An invited commentary by Bierhals is available online. Online supplemental material is available for this article.

OBJECTIVES/OBJECTIVE:To describe the histologic features that are helpful in the diagnosis of the rare bronchiolar adenomas/ciliated muconodular papillary tumors (BAs/CMPTs) during intraoperative consultation. METHODS:Multi-institutional retrospective review of frozen sections of 18 BAs/CMPTs. RESULTS:In 14 of 18 cases, BA/CMPT was the primary reason for sublobar lung resection, and in 4 cases, BA/CMPT was an incidental finding intraoperatively for resections performed for carcinoma in other lobes. There were 11 proximal-type/classic BAs/CMPTs and 7 distal-type/nonclassic BAs/CMPTs. Only 3 (16.7%) of 18 were correctly diagnosed at the time of frozen section, all of which were proximal type/classic. The remainder were diagnosed as adenocarcinoma (n = 7); invasive mucinous adenocarcinoma (n = 1); non-small cell lung carcinoma (n = 1); cystic mucinous neoplasm, favor adenocarcinoma (either mucinous or colloid type) (n = 1); favor adenocarcinoma, cannot exclude CMPT (n = 1); atypical proliferation (n = 2); mucinous epithelial proliferation (n = 1); and mucous gland adenoma (n = 1). CONCLUSIONS:BA/CMPT can potentially be misdiagnosed as carcinoma during intraoperative consultation. On retrospective review of the frozen sections, the presence of the following may help to avoid misdiagnosis: a mixture of bland ciliated columnar cells, mucinous cells, and, most important, a basal cell layer, as well as a lack of necrosis, significant atypia, and mitoses.

Cutibacterium acnes is an anaerobic bacterium commonly thought of as a culture contaminant rather than a pathogen. We present a case of Cutibacterium acnes pericarditis in a 22-year-old immunocompetent woman managed with surgical pericardial window and a 4-week course of penicillin G and review related literature on Cutibacterium acnes pericarditis.