De Quervain’s thyroiditis, sometimes referred to as subacute thyroiditis (SAT), is the most common granulomatous disease of the thyroid, typically found after a viral infection in middle-aged women. The mRNA encoding for the angiotensin-converting enzyme-2 (ACE-2) receptor is expressed in follicular thyroid cells, making them a potential target for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Besides infection, SARS-CoV-2 vaccines have also been implicated in SAT pathogenesis. We present a case of a woman developing SAT following vaccination with Comirnaty by Pfizer Inc. (New-York, USA). We performed a systematic review of similar cases available in the literature to provide a better understanding of the topic. We searched the databases PubMed and Embase and followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Patient records were then sorted according to the type of administered vaccine and a statistical analysis of the extracted data was performed. No statistically significant difference between mRNA vaccines and other vaccines in inducing SAT was found, nor was any found in terms of patient demographics, symptoms at presentation, initial, or follow-up blood tests. In our case report, we described the possible association between SARS-CoV-2 mRNA-based vaccine Comirnaty and SAT.

Background: Splenic volvulus is a rare cause of acute and chronic abdominal pain. This condition is determined by an insufficiency or absence of the ligamentous attachments, a condition known as “wandering spleen” that causes a hypermobility of the spleen. Wandering spleen could be congenital or acquired and is more frequent in women of reproductive age and in children. Symptoms may remain limited or absent for long periods of time, but complications can occur due to the torsion of the splenic vascular pedicle, resulting in symptoms ranging from an incidental finding to an acute abdomen derived from ischemic necrosis of the spleen. Case presentation: A 19-year-old male, admitted for abdominal pain and general discomfort. Considering the objective examination, further diagnostic tests were requested. Computed tomography (CT) revealed a chronic venous thrombosis of the splenic vein, hypoperfusion and malposition of the spleen, peritoneal effusion and stretching of structures in the left upper abdominal quadrant. These are strongly suspicious signs of splenic volvulus. Conclusion: The diagnosis of this rare condition can be challenging because of the variability of its symptoms and its capacity of mimicking other pathologies. Suggestive signs should be recognized in order to ensure a timely diagnosis and to choose the optimal strategy of treatment.