A Small-for-Gestational-Age Infant with MIRAGE Syndrome Who Developed Heat Stroke and Rhabdomyolysis due to Severe Temperature Instability.

MIRAGE syndrome is characterized by myelodysplasia, infection, restriction of growth, adrenal hypoplasia, genital phenotypes, and enteropathy. This report describes heat stroke and rhabdomyolysis caused by anhidrosis as a symptom of MIRAGE syndrome in a small-for-gestational-age (SGA) female neonate born at 32 weeks of gestation (birth weight, 911 g [-3.8 SD]). She developed severe temperature instability with anhidrosis, growth failure, mild developmental delay, hypothyroidism, and intractable enteropathy. On day 156, her temperature reached 42.0°C; her fever persisted for 2 h with prolonged irritability. Her serum creatine kinase level increased to a peak value of 12,716 (normal range, 43-321) IU/L. The clinical feature was diagnosed as rhabdomyolysis caused by heat stroke, which resulted from physical exertion with anhidrosis. Her SAMD9 variant was c.2945G>A, p. (Arg982His). Neonatologists should be aware of MIRAGE syndrome as a differential diagnosis of SGA with temperature instability.

Inflammatory myofibroblastic tumor of the posterior mediastinum: an older adult case with anaplastic lymphoma kinase abnormalities determined using immunohistochemistry and fluorescence in situ hybridization.

Inflammatory myofibroblastic tumor (IMT) is a rare neoplasm that usually occurs in children and young adults. Anaplastic lymphoma kinase (ALK) abnormalities in IMT, determined using immunohistochemistry and/or molecular genetic studies, including fluorescence in situ hybridization (FISH), have almost been limited to children and young adults. In elderly cases of IMT, these ALK abnormalities are very rare. We report on a case of IMT arising in the posterior mediastinum of a 59-year-old Japanese man that showed ALK abnormalities determined using immunohistochemistry and FISH, suggesting the neoplastic nature of a subset of IMTs in older patients similar to those in younger ones and the presence of an additional mechanism(s) that allows them to start to grow late.