Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (DM) is characterized by mild or absent muscle involvement and unique skin lesions such as cutaneous ulceration and palmar papules, commonly associated with rapidly progressive interstitial lung disease (RP-ILD), causing fatal outcomes. Spontaneous intramuscular hemorrhage (SIH) is an extremely rare but severe complication that remains under-recognized in DM. Here, we report a case of multiple SIH in a 72-year-old Japanese woman with anti-MDA5 antibody-positive DM and RP-ILD. The patient initially presented with fever, fatigue, and abnormal liver function, leading to a provisional diagnosis of autoimmune hepatitis. Following a 3-week moderate-dose prednisolone treatment, bilateral thigh hematomas suddenly developed without trauma or anticoagulant therapy. Laboratory findings revealed elevated creatine kinase and ferritin levels, reduced factor XIII (F13) activity, and anemia. Computed tomography (CT) imaging showed hematomas in multiple muscles and ILD. Although high-dose prednisolone administration gradually ameliorated the intramuscular hemorrhage, skin manifestations indicative of DM and dyspnea on exertion emerged after tapering prednisolone. Exacerbation of ILD was observed on CT imaging. Comprehensive analysis detected anti-MDA5 and anti-Ro52 antibodies without anti-F13 autoantibody, eventually leading to the diagnosis of anti-MDA5 antibody-positive DM with SIH and RP-ILD. Despite aggressive immunosuppressants, she died of RP-ILD-related respiratory failure. This case highlights the importance of considering DM as a differential diagnosis and investigating cutaneous manifestations indicative of DM in cases where the SIH etiology is unclear. Evaluation of myositis-specific and myositis-associated autoantibodies is crucial to ensure adequate diagnosis when SIH associated with DM is highly suspected.

Moyamoya disease is a rare cerebrovascular occlusive disorder, and its natural course remains incompletely understood. Although rare, extracranial arterial lesions can develop in patients with moyamoya disease. We report the case of a 35-year-old Japanese woman with moyamoya disease who was referred to our department for the treatment of severe chronic mesenteric ischemia. She had a several-year history of postprandial abdominal pain and experienced two episodes of gastric ulcer perforation in the past year. Enhanced computed tomography revealed that the patient had a common trunk of the celiac and superior mesenteric arteries, which was occluded at its origin. The patient underwent an aorta to superior mesenteric artery bypass with a great saphenous vein graft. The postoperative period was uneventful, and the patient is now free of symptoms. The present case suggests that a patient with moyamoya disease can develop symptomatic mesenteric arterial lesions.

Helium inhalation has increased, but most cases are either minor injuries or deaths; there have not yet been any reported cases of brain death leading to organ donation. We report a patient who attempted helium inhalation and was declared brain dead and became an organ donor without complications. To the best of our knowledge, this is the first reported case of deceased organ donation following helium asphyxiation in Japan. The patient in cardiac arrest was found with a helium-filled vinyl bag sealed around the neck. During emergency medical transport to the hospital, a spontaneous return of circulation was obtained after 31 minutes of cardiopulmonary resuscitation. Upon hospital arrival, the physical examination revealed dilated pupils with no response to light. Electrocardiography showed widespread ST-segment depression and ST-segment elevation in augmented Vector Right, as well as elevated cardiac enzymes and decreased myocardial contractility. Head computed tomography revealed diffuse cerebral edema and loss of the gray-white matter boundary without signs of air embolism in the cerebral and coronary arteries. Despite comprehensive post-cardiac arrest care with recovery of organ function, brain death was confirmed on day 4 after hospitalization. The family consented to organ donation on the 11th day of hospitalization. The heart, lungs, liver, and two kidneys were successfully transplanted and all organs functioned. All organ grafts were functioning well at the 3-month follow-up. Our case demonstrates that brain death caused by helium inhalation is not a contraindication to organ donation.

Brain metastases from malignant tumors are generally known to have a poor prognosis. One of the major reasons for this is the lack of efficacy of anti-tumor drugs compared to other organs. One of the major reasons for this is the lack of efficacy of anti-tumor drugs compared to other organs. Malignant melanoma is a highly malignant tumor that occurs mainly in the skin and is relatively prone to brain metastasis. In this case report, we report two cases of malignant melanoma with brain metastases that were treated with a combination of radiotherapy and chemotherapy and had long-term survival. Case 1 was a 51-year-old Japanese man with primary melanoma of the chest; the pathological staging was pT4aN1aM0, stage IIIC. He developed multiple brain metastases two years and three months after the initial resection. Case 2 was a 23-year-old Japanese woman with primary melanoma of the upper extremities; the pathological staging was pT1bN1aM0, stage IIIA. She developed brain metastases one year and nine months after the initial resection. Both patients had positive BRAF gene mutations in their primary tumors. The combination of BRAF inhibitors, immune checkpoint inhibitors, and stereotactic radiotherapy resulted in long-term survival of more than 5 years for Case 1 and more than 6 years for Case 2. With advances in chemotherapy and radiotherapy, the prognosis for patients with brain metastases, not only malignant melanoma, is expected to improve further in the future. Although rare, malignant melanoma is known to occur in various organs other than the skin. We report this case because we believe that our case report will be of interest to physicians who treat the above organs.