In recent years, there have been remarkable technological advances in imaging and molecular biology that have permitted definitive diagnoses in cases that were previously undiagnosable. This has been accompanied by the emergence of new disease concepts that integrate multiple diseases. Furthermore, new treatments have been developed for diseases for which there was no effective treatment, and prognoses have greatly improved. However, even in this era, medical interviews and physical examinations remain extremely important in medical practice.

The field of pediatric neurology is based on neurological symptomatology, as well as factors such as growth and development. Although many patients may be uncooperative in medical examinations and insufficient neurological findings may be obtained, the symptoms of these patients are relatively easy to understand because they are, in a sense, “honest.”

In the first half of the lecture, I will discuss cases with gait disturbance as a typical neurological symptom, and introduce relationships among the clinical course, neurological symptoms, clinical examinations, and neuroimaging findings. This will be followed in the second half by a discussion of cases with epileptic seizures.

Japan’s first living-donor lung transplant was successfully performed in 1998, 15 years after the world’s first successful lung transplant by the Toronto Group. More than 20 years have passed since then, and more than 1,000 lung transplants have now been performed in Japan. The results have been excellent, with a 5-year survival rate of over 70% and a 10-year survival rate of over 60%, which are some of the highest survival rates in the world. The number of lung transplants has been increasing globally over time, and in Japan, the number of lung transplants exceeded 100 cases per year for the first time in 2022. However, the annual number of pediatric lung transplants worldwide is only about 100, and only about 20 cases involve patients under 10 years of age. Japan is the only country in the world where living-donor lung transplantation continues to be performed, and living-donor lung transplantation for children is an essential treatment option because of the severe chronic cadaveric donor shortage in Japan. Therefore, in the hope that lung transplantation will become an established and increasingly used treatment option for pediatric patients suffering from chronic respiratory failure, the current status and future of lung transplantation are outlined in this article.

Targeted radionuclide therapy involves inducing cell death by radiolabeled substances that specifically bind to molecules expressed in target tissues, which allows the substances to accumulate in these tissues. In the past, this treatment has only been used with ¹³¹I for thyroid diseases. However, new preparations with various targets have recently been developed and are now used in clinical practice. These agents are labeled with a diagnostic nuclide, which allows for patient selection and dose assessment in advance. Therefore, unlike conventional chemotherapy or immunotherapy, this therapy uses a combination of therapeutics and diagnostics, and thus, is referred to as theranostics. In the pediatric field, in addition to use in thyroid diseases, ¹³¹I-MIBG for neuroblastoma is being considered for insurance coverage.

Lymphangiomas, also known as lymphatic malformations, lymphangiomatosis, Gorham’s disease, and lymphangiectasia, are challenging lymphatic anomalies marked by abnormal growth and invasion of lymphatic tissue. Cystic lymphangioma presents at birth as a clump of lymphatic cysts of different sizes, leading to a variety of symptoms depending on the anatomical location. Lymphangiomatosis is characterized by widespread infiltration of lymphatic tissue, and can result in a range of complications including chylothorax, pericardial effusion, and bone dissolution, with symptoms dependent on the infiltration site. Gorham’s disease results in gradual erosion of bones throughout the body, whereas lymphangiectasia causes swelling and lymph fluid leakage due to congenital anomalies in lymph vessel structures. These disorders may appear similar clinically, but are distinct in their pathophysiology and radiological signatures.

Advances have been made in the genetic understanding of these diseases, with PIK3CA/RAS gene mutations identified in the lesions. Sirolimus, an mTOR inhibitor, has been recognized for its efficacy in managing these conditions and was approved in Japan in 2021 after showing good symptom control in national and international studies. In this review, the pathogenesis and diagnosis of lymphatic anomalies and emerging treatments will be introduced for pediatricians and radiologists.

We have reported the usefulness of lymphatic ultrasound using an 18 MHz linear probe (Noblus, Fuji Film). Degeneration of lymphatic vessels through ectasia, sclerosis, and obstruction occurs in lymphedema-affected limbs. Evaluation of lymphatic degeneration using ultrasonography has improved surgical outcomes for procedures such as lymphaticovenous anastomosis.

When identifying lymph vessels, we use the D-CUPS index to differentiate these vessels from veins, rather than use of color Doppler. The characteristics of the lymphatic vessels are defined as “cross” (passing through nearby veins), “uncollapsible” (do not collapse under pressure from the probe), “parallel” (multiple lymph vessels run in parallel), and located under the superficial fascia.

Lymphatic ultrasound is also useful for diagnosis of lymphatic function, as a minimally invasive examination that can be readily performed by medical staff. Conventional examinations of lymphatic function include lymphoscintigraphy and lymphangiography, but few medical centers can perform these methods. More widespread use of lymphatic ultrasound may lead to improved diagnosis and treatment of various diseases.

Lymphatic diseases can be caused by various factors, with primary pathologies involving damage to the lymphatic vessels and disruption due to congestion or excessive lymph production. While imaging of the lymphatic system remains under development, recent advances allow for some evaluation of hepatic lymph flow. We treat pediatric patients using techniques such as lymphangiography, thoracic duct embolization, thoracic duct disruption, and intrahepatic lymphatic embolization to address conditions such as chylothorax, chylous ascites, plastic bronchitis, chylopericardium, and protein-losing enteropathy. This paper discusses the pathologies of lymphatic diseases based on actual cases, indicating areas of consensus and future challenges.

Cherubism is a rare autosomal dominant disorder that is characterized by bilateral mandibular swelling. It typically develops bilaterally and symmetrically, and tends to regress after puberty. Unilateral involvement of cherubism is extremely rare. Due to its self-limiting nature, treatment options range from observation to surgery. We report two cases of sibling-onset unilateral and bilateral cherubism. Both cases showed a tendency to regress after surgery.