(1) Background: Currently, multisystem inflammatory syndrome in children (MIS-C) is diagnosed based on clinical symptoms and laboratory findings of inflammation in the body. Once MIS-C is diagnosed, children will need to be followed over time. The imaging modalities most commonly used in the evaluation of patients with MIS-C include radiographs, ultrasound (US), and computed tomography (CT). Our study aims to summarise the literature data for the main gastrointestinal and pulmonary imaging features in children diagnosed with MIS-C and to share a single-centre experience. (2) Methods: We present the imaging findings in a cohort of 51 children diagnosed with MIS-C, admitted between December 2020 and February 2022. Imaging studies include chest and abdominal radiographs, thoracic, abdominal, and neck US and echocardiography (ECHO), and CT of the chest, abdomen, and pelvis. (3) Results: In accordance with the results in other studies, our observations show predominantly gastrointestinal involvement (GI) with ascites (33/51, 65%) and lymphadenopathy (19/51, 37%), ileitis or colitis (18/51, 35%), some cases of splenomegaly (9/51, 18%), hepatomegaly (8/51, 16%), and a few cases of renal enlargement (3/51, 6%) and gallbladder fossa oedema/wall thickening (2/51, 4%). Most common among the thoracic findings are posterior–basal consolidations (16/51, 31%), pleural effusion (14/51, 27%), and ground-glass opacities (12/51, 24%). We also register the significant involvement of the cardiovascular system with pericarditis (30/51, 58%), pericardial effusion (16/51, 31%), and myocarditis (6/51, 12%). (4) Conclusions: Radiologists should be aware of those imaging findings in order to take an important and active role not only in applying an accurate diagnosis, but also in the subsequent management of children with MIS-C. Radiological findings are not the primary diagnostic tool, but can assist in the evaluation of the affected systems and guide treatment.

A hydropneumothorax is an uncommon complication of pneumonia, particularly in pediatric patients, and typically arises secondary to conditions such as malignancies, esophageal-pleural fistula, thoracic trauma, or thoracocentesis. While pneumothorax is rarely reported in adults with COVID-19 and is even less common in children, isolated cases have been noted in those with Multisystem Inflammatory Syndrome in Children (MIS-C). A recent alert has also been issued about increased Group A Streptococcus (GAS) infections in Europe. Against this background, the primary aim of this case report is to describe a rare and severe complication of pneumonia in a previously healthy child with MIS-C and a positive throat culture for GAS.

Splenic epidermoid cysts are rare benign congenital tumors. However, if the cyst is not completely removed, it can reoccur. Laparoscopic splenectomy in children is being conducted more often, but it is a therapeutic challenge in cases of a giant cyst. We report a case of a 15-year-old girl who presented with nausea, anorexia and abdominal pain. The ultrasound showed a giant well-defined hypoechoic cyst with diffuse internal echoes. Computed tomography revealed a cystic mass (92/124/102 mm) without contrast enhancement. Anti-Echinococcus ELISA IgG was negative, and serum tumor markers CA 19-9 79.1 U/mL (N < 34) and CA-125 39.6 U/ML (N < 35) were elevated. Before the operation, the girl was vaccinated for Haemophilus influenzae, Pneumococci and Meningococci. Laparoscopic splenectomy was performed. The patient’s postoperative course was uneventful. Histopathology indicated a cyst walled by multilayered squamous epithelium positive for cytokeratin AE1/AE3. The diagnosis epidermoid cyst was confirmed.