Pulmonary infarction secondary to pulmonary embolism: An evolving paradigm.

BACKGROUND AND OBJECTIVE: Pulmonary infarction (PI) from pulmonary embolism (PE) remains an entity of unclear aetiology. PI has been thought to occur in elderly patients with cardiopulmonary disease. We hypothesize younger patients without cardiopulmonary comorbidities are at highest risk. Our study aims to characterize PI clinically and radiographically, determine associated risk factors and determine their clinical significance. METHODS: We conducted a single-centre retrospective review of 367 consecutive patients with PE. Clinical and radiographic data were compared between patients with and without PI using chi-square and F-tests. Univariate and multivariate analyses were performed to evaluate risk factors for PI. RESULTS: PI occurred in 62 of 367 patients with acute PE (16.9%). Patients with PI were significantly younger (48 ± 20.3 vs 59.6 ± 17.2 years, P < 0.01), with lower pulmonary embolism severity index (PESI) scores (73.7 ± 38.1 vs 91.9 ± 37.5 years, P < 0.01) and endorsed chest pain with significantly higher frequency (65% vs 39%, P < 0.01). There was no significant difference in other clinical symptoms, hospital length of stay or mortality between groups. Presence of radiographic cardiopulmonary disease was significantly lower in patients with PI (emphysema: 5% vs 22%, P = <0.01; aortic atherosclerosis: 23% vs 43%, P = <0.01). In multivariate analysis, age ≤33 (OR 3.5 CI: 1.37-8.95, P < 0.01), chest pain (OR 2.15 CI: 1.15-4.00, P = 0.02) and pleural effusion (OR 2.18 CI: 1.08-4.41, P = 0.03) increased PI risk and presence of emphysema decreased risk (OR 0.21 CI: 0.06-0.70, P = 0.01). CONCLUSION: Younger patients without cardiopulmonary comorbidities are at highest risk of PI. Chest pain and pleural effusion significantly increased risk of PI while presence of radiographic emphysema reduced risk.

Case Records of the Massachusetts General Hospital. Case 30-2015: A 50-Year-Old Man with Cardiogenic Shock.

A 50-year-old man with a history of cardiomyopathy and progressive muscle weakness was admitted with cardiogenic shock. Electroencephalography showed total suppression of cerebral activity; ventilator support was withdrawn, and he died. An autopsy was performed.

High rate of unnecessary thymectomy and its cause. Can computed tomography distinguish thymoma, lymphoma, thymic hyperplasia, and thymic cysts?

PURPOSE: To determine the non-therapeutic thymectomy rate in a recent six-year consecutive thymectomy cohort, the etiology of these unnecessary thymectomies, and the differentiating CT features of thymoma, lymphoma, thymic hyperplasia, and thymic cysts. MATERIALS AND METHODS: Electronic data base query of all thymectomies performed at the Massachusetts General Hospital from 2006 to 2012 yielded 160 thymectomy cases, 124 of which had available imaging. The non-therapeutic thymectomy rate (includes thymectomy for lymphoma and benign disease) was calculated. Preoperative clinical and CT imaging features were assessed by review of the in-house electronic medical record by 2 thoracic surgeons and 2 pathology-blinded radiologists, respectively. RESULTS: The non-therapeutic thymectomy rate of 43.8% (70/160) was largely secondary to concern for thymoma and was comprised of lymphoma (54.3%, 38/70), thymic bed cysts (24.3%, 17/70), thymic hyperplasia (17.1%, 12/70), and reactive or atrophic tissue (4.3%, 3/70). Among these four lesions, there were significant differences in location with respect to midline, morphology, circumscription, homogeneity of attenuation, fatty intercalation, coexistent lymphadenopathy, overt pericardial invasion, and mass effect (p<0.001). True thymic cysts ranged in attenuation from -20 to 58Hounsfield units (HU), with a mean attenuation of 23HU. CONCLUSION: The high rate of unnecessary thymectomy was due to misinterpretation of thymic cysts, thymic hyperplasia, and lymphoma as thymoma on chest CT. This study demonstrates differentiating features between thymoma, lymphoma, thymic hyperplasia, and thymic cysts on chest CT which may help triage more patients away from thymectomy toward less invasive and non-invasive means of diagnosis and thereby lower the non-therapeutic thymectomy rate.