Katsuhiko Aoki

MRI reveals fetus in fetu in the mediastinum

Fetus in fetu is an extremely rare condition in which a fetiform calcified mass is contained within the newborn or infant, often in the retroperitoneal cavity. We report a case of a fetus in fetu in the posterior mediastinum of a newborn. The prospective diagnosis was made by fetal US and MRI and confirmed by postnatal plain radiograph, CT and MRI.

Syringohydromyelia in Hajdu-Cheney syndrome

We report the case of a 10-year-old boy with typical manifestation of Hajdu-Cheney syndrome. MRI demonstrated syringohydromyelia involving almost the entire spinal cord, although neurological symptoms had not yet developed. Syringohydromyelia is considered to be a sequel to progressive basilar invagination and is one of the essential features of this rare osteolytic bone dysplasia.

Desmoplastic small cell tumor of soft tissue: Molecular variant of EWS-WT1 chimeric fusion

A 7‐year‐old girl was hospitalized because of a tumorous mass in her left periorbital region. The tumor was removed by local excision. The soft‐part tumor recurred in the parotid gland region 4 months later, and a second recurrence was noted on the left side of the neck 3 years and 3 months thereafter. The patient had not received chemotherapy or local irradiation. Histological and immunohistochemical examinations of the recurrent masses revealed morphological characteristics of small cell proliferation with desmoplastic stroma that were similar to those of the initial tumor. The cellular components showed immunoreactivity for desmin, cytokeratin, vimentin, and epithelial membrane antigen in part, but the cells were negative for myogenin, CD99, and neuron‐specific enolase. These findings suggested a diagnosis of desmoplastic small cell tumor, despite its extra‐abdominal location. The histological diagnosis was confirmed by reverse transcriptase polymerase chain reaction, which demonstrated an EWS‐WT1 chimeric fusion gene. An in‐frame fusion of EWS exon 9 and WT1 exon 8 was subsequently identified by cloning and sequencing. The chimeric fusion gene might be related to the tissue‐specific phenotype of desmoplastic small cell tumors, although further investigation of this speculation is necessary.

Computed radiography in pediatrics

Computed radiography (CR) has various advantages such as dynamic range. Diagnostic accuracy with CR using reduced radiation dose is considered comparable with that of conventional film-screen radiography in diagnosing apparent chest abnormalities. In addition to reducing the radiation dose, delineation of the various structures in infants can be obtained with CR using postprocessing. Even in cases involving inadequate exposure, appropriate information can be obtained by postprocessing. For these reasons, the cumulative dose of radiation exposure will be reduced. Thus, reduction of the radiation dose is the greatest advantage of using CR in pediatrics.

Results for 79 patients with neuroblastoma detected through mass screening at 6 months of age in a single institute

Background: In Japan, mass screening for neuroblastoma has been performed at 6 months of age to improve the prognosis of this condition for more than 20 years. In recent years, most neuroblastomas detected by mass screening were considered to have favorable biological features and sometimes tend to regress spontaneously.

New brittle bone disorder: report of a family with six affected individuals.

We report on a family in which four females and two males in three generations had a previously undescribed brittle bone disorder that was dominantly transmitted through a maternal line. The cardinal manifestations of the disorder comprised dolichocephaly with frontal bossing, hypoplasia of the midface, postpubertal prognathism, micromelic short stature, coarse trabeculae of the entire skeleton, and bone fragility of variable degrees. Mild spondylar modification and iliac hypoplasia were other hallmarks that were recognized in childhood. The proband, a 19-year-old male, was most severely affected with multiple wormian bones in the calvaria, repetitive fractures, intractable bowing of the legs and forearms, and pseudofractures of the long bones with metaphyseal narrowing. His male cousin was next severely affected with angular deformity restricted to the forearm. The four females were much less affected without angular deformity. The mode of inheritance was thus consistent with either an autosomal dominant trait with sex-influence or an X-linked semidominant trait. Histological bone examination in the proband showed atrophy and fibrous degeneration of the lamellar trabeculae and disorganized chondro-osseous junction, which implied that the disorder involved both intramembranous and enchondral ossifications.

Ischial hypoplasia, tibial hypoplasia and facial abnormalities: a new syndrome?

Abstract A child with facial abnormalities, short stature and a variety of skeletal alterations is reported. The facial abnormalities comprised low-set ears, short nose with a long philtrum, micrognathia and cleft palate. The skeletal alterations included ischial hypoplasia, malformations of the cervical spine, hypoplasia of the lesser trochanters, tibial hypoplasia with bowing of the lower legs, tibio-fibular diastasis with malformed distal tibial epiphyses, clubfeet and brachymesophalangy. The constellation of clinical and radiological findings in the present patient do not fit any known malformation syndrome.

Infantile hemangioendothelioma of the thymus with massive pleural effusion and Kasabach‐Merritt syndrome: Histopathological, flow cytometrical analysis of the tumor

Infantile hemangioendothelioma of the thymus is a rare disease. We describe a patient who developed a large anterior mediastinal mass, severe thrombocytopenia and massive pleural effusion at 1 month of age. Glucocorticosteroid and irradiation therapy had no effect on either the tumor size or clinical symptoms and the tumor was resected subtotally. Three months after the subtotal resection, the remaining tumor had almost disappeared and the symptoms had resolved. The patient has now been well for 1 year after surgery without evidence of recurrence. The tumor tissue was characterized by prominent vascular endothelial proliferation intermixed with a normal thymic structure, producing a picture consistent with that of an infantile hemangioendothelioma in the thymus, lmmunohistochemically, the tumor cells showed positive staining for vimentin, factor VIII and CD34. The DNA stemline and proliferative activity were examined by flow cytometry, which revealed a diploid stemline with a low growth fraction. DNA content and cell cycle analyses of the tumor tissue may be useful for predicting the biological behavior of the tumor.