Nevus Sebaceous and Its Association With Neurologic Involvement

Several terms are widely used to define cutaneous lesions affecting the epidermis in association with extracutaneous lesions. Recently, based on the wide spectrum of cutaneous epidermal lesions, the various underlying molecular mechanisms and patterns of associated features have led to improved definitions of these disorders. Nevus sebaceous syndrome has been placed under the umbrella term of epidermal nevus syndrome, in which the nevus sebaceous, a congenital hamartomatous lesion of the epidermis, is associated with anomalies involving the brain, eyes, and bones. Nevus sebaceous and neurologic manifestations were evaluated particularly based on their degree of intellectual delay, seizure type, treatment response, and electroencephalography and neuroradiological findings. A review of the literature in this topic is reported.

KRAS G12D mosaic mutation in a Chinese linear nevus sebaceous syndrome infant

BACKGROUND

Linear nevus sebaceous syndrome (LNSS) is a multisystem disorder that includes nevus sebaceous and central nervous system, ocular and skeletal anomalies. We report the first case of a KRAS G12D mosaic mutation in a patient diagnosed with LNSS.

CASE PRESENTATION

A 3-month-old female with a clinical diagnosis of LNSS presented with intermittent epilepsy. Her mother carefully collected a skin lesion sample from scratched-off scurf obtained from the patient's nails. DNA was extracted, and long-range PCR was performed to amplify the KRAS gene, which was then analyzed by next-generation sequencing. The results revealed the presence of a low-level heterozygous mutation in the KRAS gene (c.35C>T; p.G12D, 5 %).

CONCLUSIONS

These findings suggest that the KRAS somatic mosaic mutation in this patient may have caused her skin and eye lesions and epilepsy. With this correct diagnosis, the infant can be effectively treated.

A rare case of chylothorax in a patient with schimmelpenning syndrome

Chylothorax originating in a patient with Schimmelpenning syndrome is rare and poses a problem in diagnosis and treatment. A 22-year-old male was admitted with dyspnea indicative of a large pleural chylous effusion. Besides conservative dietary treatment measures, the chylous effusion was drained (2,000 mL/day). Computed tomography-lymphography after ligation of the thoracic duct and pleurectomy revealed a small collateral flow of chylous fluid toward the chest wall and entering the thorax. Eventually, local radiation therapy with 36 Gy effectively treated the chylothorax. Five months later, an epitheloid angiosarcoma developing from a preexisting cutaneous lesion was detected and treated by surgical resection.

Mosaic RASopathies

"RASopathies" are a group of developmental syndromes with partly overlapping clinical symptoms that are caused by germline mutations of genes within the Ras/MAPK signaling pathway. Mutations affecting this pathway can also occur in a mosaic state, resulting in congenital syndromes often distinct from those generated by the corresponding germline mutations. For syndromes caused by mosaic mutations of the Ras/MAPK signaling pathway, the term "mosaic RASopathies" has been proposed. In the following article, genetic and phenotypic aspects of mosaic RASopathies will be discussed.