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Chondromyxoid fibroma (CMF) is a rare benign cartilaginous neoplasm that most frequently occurs in the metaphysis of long bones in adolescents and young adults. The most common symptom is pain and/or swelling in the affected area. Radiographs typically show a well-defined, eccentric lytic lesion with sclerotic margins and scalloped or lobulated borders. Unlike other cartilaginous neoplasms, matrix calcification is uncommon. On magnetic resonance imaging (MRI), CMF usually exhibits low to intermediate signal intensity on T1-weighted sequences and heterogenous high signal intensity on T2-weighted sequences. Contrast-enhanced MRI demonstrates intense homogeneous, heterogeneous or peripheral enhancement. Histologically, CMF is composed of lobules of stellate to spindle-shaped cells in a myxoid background. The periphery of the lobules is generally hypercellular, imparting a characteristic zonal architecture. Recent molecular studies have identified alteration of glutamate metabotropic receptor 1 (GRM1) gene, and GRM1 positivity by immunohistochemistry has emerged as a reliable surrogate marker for this molecular event. Curettage or en bloc resection is the treatment of choice, with a non-negligible risk for local recurrence. This review provides an updated overview of the clinical, radiological, histological, immunohistochemical and molecular genetic features of CMF and discusses the differential diagnosis of this unusual neoplasm.
BACKGROUND:Folic acid (FA), an essential nutrient for one-carbon metabolism, has been implicated in metabolic disease development. Although FA supplementation during pregnancy prevents neural tube defects, its broader metabolic effects remain unclear. METHODS:Eight-week-old C57BL/6 female mice were mated and fed an FA-deficient or control diet during gestation. Male offspring were weaned onto either a normal or Western-type diet, and monitored until 3 months of age. In the Growing Up in Singapore Towards healthy Outcomes (GUSTO) birth cohort, associations between maternal plasma FA levels during pregnancy and ectopic fat accumulation in offspring at age 6 years were examined. RESULTS:Maternal FA deficiency promoted ectopic fat accumulation in the liver and skeletal muscle of male offspring and increased obesity susceptibility. These effects were associated with disrupted one-carbon metabolism and impaired fatty acid β-oxidation, potentially due to reduced expression of Adenosylmethionine Decarboxylase 1 (Amd1) in male offspring. Consistently, in the GUSTO cohort, maternal plasma FA concentrations were inversely associated with hepatic and muscular fat accumulation in children. CONCLUSION:Maternal FA status plays a critical role in regulating male offspring metabolic health. Maintaining adequate maternal plasma FA levels, rather than focusing solely on dietary intake, may be essential for preventing ectopic fat accumulation in the next generation.
Appropriate timing of mesiodens extraction may reduce the risk of eruption disturbance of the maxillary central incisor. We encountered a case in which severe displacement of the maxillary central incisor tooth germ was associated with the presence of two mesiodens. After extraction of the mesiodens, the axis of the central incisor improved spontaneously, and the tooth subsequently erupted without orthodontic traction. We hypothesized that this spontaneous eruption was related to the developmental stage of the tooth germ, during which improvement of the abnormal axis could occur prior to eruption. To further investigate this hypothesis, we retrospectively assessed 49 maxillary central incisors with positional abnormalities associated with mesiodens. Among children diagnosed with mesiodens at 5-6 years of age, approximately 70% showed positional abnormalities of the maxillary central incisor tooth germ, whereas all incisors diagnosed at 7 years of age exhibited positional abnormalities. In the present investigation, mesiodens were extracted before the maxillary central incisors reached one-quarter root formation. The rate of positional improvement of the central incisor tooth germ affected by mesiodens tended to decrease as the developmental stage of the incisor advanced after mesiodens extraction. However, overall, more than 85% of the maxillary central incisors erupted spontaneously. This study underscores the importance of evaluating the stage of root development of the permanent maxillary central incisor when determining the timing of mesiodens extraction and predicting eruption outcomes.
Calcifying aponeurotic fibroma (CAF) is a rare benign but locally aggressive mesenchymal tumor that primarily occurs in the distal extremities of children and adolescents. It typically presents as a slow-growing, painless, poorly circumscribed mass, often of prolonged duration. Radiographs may reveal a soft-tissue mass with a variable extent of fine stippled calcifications. On magnetic resonance imaging, CAF usually appears as an ill-defined subcutaneous mass with low to intermediate signal intensity on T1-weighted sequences and heterogenous high signal intensity on T2-weighted sequences. Areas of calcification exhibit low signal intensity on all pulse sequences. Intense heterogeneous enhancement is seen after intravenous contrast administration. Histologically, CAF is characterized by a fibromatosis-like component and a nodular calcified component. By immunohistochemistry, the tumor cells are variably positive for smooth muscle actin, muscle-specific actin and CD99 but negative for desmin and β-catenin. Moreover, frequent expression of ETS transcription factor ERG (ERG) and epidermal growth factor (EGF) has been demonstrated. Recent molecular studies have identified the presence of a recurrent fibronectin 1 (FN1)-EGF gene fusion. Surgical excision is the treatment of choice for CAF, but local recurrence is common due to its infiltrative nature. This review provides an updated overview of the clinical, radiological, morphological, immunohistochemical and molecular genetic features of CAF and discusses the differential diagnosis of this uncommon condition.
