[Skin markers of communicating dermal sinus: report of two cases]. / Anomalies cutanées des sinus dermiques communicants: à propos de 2 cas.

Skin abnormalities in the spinal lumbosacral region of infants are not infrequent. Physicians should look for underlying spinal malformations. We report 2 cases of dermal sinus in infants revealed by severe, acute meningitis. The dermal sinus is an abnormal tract between the skin and underlying neural structures, most often located in the lumbosacral region. It may end blindly in the subcutaneous tissues, or it may extend into the medullary space. The diagnosis should be suspected in patients with other skin findings: localized hypertrichosis, subcutaneous lipomas, hyperpigmented lesions, etc. It must be distinguished from the very frequent coccygeal pits (4% of newborns), which require no treatment. Magnetic resonance imaging should be done every time the diagnosis is suspected. Recurrent bacterial meningitis or meningitis caused by unusual bacteria is frequently associated with dermal sinus. A variety of neurologic abnormalities have been described: sensory changes, motor weakness, reflex changes, abnormal bowel and bladder function, etc. Infants generally have few neurologic symptoms, such as delayed walking or sphincter control. Orthopaedic abnormalities are rare. The dermal sinus tract needs to be detected at an early stage in order to avoid these complications, which can be prevented by early surgery.

[Childhood medulloblastoma]. / Le médulloblastome de l'enfant.

Medulloblastoma is one of the most common malignant childhood brain tumors. It is a primitive neuroectodermal tumor (PNET) and predominantly arises in the cerebellum and 4th ventricle. Most cases of medulloblastoma are sporadic, but some predisposition syndromes are known, such as SUFU and Gorlin syndromes. Most often intracranial hypertension reveals the disease typically with headache and vomiting. However, the frequent atypical presentation should not delay neuroradiological investigations. Brain and spinal MRI can establish the diagnosis of posterior fossa tumor and define the extent of the disease. CSF study completes the staging. Histologic examination of the tumor confirms the diagnosis of medulloblastoma. Patients are classified into 2 risk groups: standard-risk medulloblastoma, defined by nonmetastatic disease treated by total or subtotal tumor resection; and high-risk patients who have disseminated disease and/or residual disease. Tumor molecular genetic findings allow the use of emerging prognostic factors and may ultimately contribute to the development of targeted therapy. Current treatment in the oldest children combines surgical resection followed by radiotherapy and chemotherapy. The aim of recent studies was to increase survival and decrease sequelae by reducing CSI in older children with standard risk medulloblastoma. Treatment in younger patients is as much as possible restricted to surgery and chemotherapy. However, long-term sequelae after treatment for medulloblastoma remain frequent and the detection and treatment of those sequelae is an essential part of the follow-up of the patients.