In Situ Pulmonary Arterial Thrombosis: Literature Review and Clinical Significance of a Distinct Entity.

Filling defects identified in the pulmonary arterial tree are commonly presumed to represent an embolic phenomenon originating from thrombi formed in remote veins, particularly lower-extremity deep venous thrombosis (DVT). However, accumulating evidence supports an underappreciated cause for pulmonary arterial thrombosis (PAT), namely, de novo thrombogenesis-whereby thrombosis arises within the pulmonary arteries in the absence of DVT. Although historically underrecognized, in situ PAT has become of heightened importance with the emergence of SARS-CoV-2 infection. In situ PAT is attributed to endothelial dysfunction, systemic inflammation, and acute lung injury and has been described in a range of conditions including COVID-19, trauma, acute chest syndrome in sickle cell disease, pulmonary infections, and severe pulmonary arterial hypertension. The distinction between pulmonary embolism and in situ PAT may have important implications regarding management decisions and clinical outcomes. In this review, we summarize the pathophysiology, imaging appearances, and management of in situ PAT in various clinical situations. This understanding will promote optimal tailored treatment strategies for this increasingly recognized entity.

Incidental Discovery of a Chronically Ruptured Ovarian Dermoid in a Patient With Right Upper Quadrant Pain.

Ovarian neoplasms are categorized based on histopathologic features into epithelial surface cell tumors, germ cell tumors (teratomas), sex cord-stromal tumors, and metastases. Teratomas are the most common ovarian germ cell neoplasms. They are generally slow-growing lesions and can get fairly large before becoming symptomatic. The lesions are often incidentally discovered during imaging for other diagnostic purposes. Complications are uncommon but occur more commonly with larger lesions and include torsion, malignant degeneration, rupture, and rarely infection. When sizable, ovarian dermoid can rarely rupture and result in spillage of proteinaceous content into the peritoneal cavity, which can lead to chemical peritonitis. Additionally, the lesion can fragment into smaller lesions and can get implanted at different sites within the abdomen and pelvis. We present a case with an atypical presentation of a ruptured dermoid in a patient presenting with right upper quadrant pain who underwent sonographic evaluation, which demonstrated acute calculus cholecystitis but incidentally was found to have a partially calcified right subphrenic mass. Subsequent evaluation with computed tomography (CT) demonstrated multiple scattered peritoneal and mesenteric masses containing fat and calcification, highly suggestive of a chronically ruptured dermoid cyst.