Somatic deletion of the NF1 gene in a neurofibromatosis type 1-associated malignant melanoma demonstrated by digital PCR

BACKGROUND: Neurofibromatosis type 1 (NF1) is the most common hereditary neurocutaneous disorder and it is associated with an elevated risk for malignant tumors of tissues derived from neural crest cells. The NF1 gene is considered a tumor suppressor gene and inactivation of both copies can be found in NF1-associated benign and malignant tumors. Melanocytes also derive from neural crest cells but melanoma incidence is not markedly elevated in NF1. In this study we could analyze a typical superficial spreading melanoma of a 15-year-old boy with NF1 for loss of heterozygosity (LOH) within the NF1 gene. Neurofibromatosis in this patient was transmitted by the boy's farther who carried the mutation NF1 c. 5546 G/A. RESULTS: Melanoma cells were isolated from formalin-fixed tissue by liquid coverslip laser microdissection. In order to obtain statistically significant LOH data, digital PCR was performed at the intragenic microsatellite IVS27AC28 with DNA of approx. 3500 melanoma cells. Digital PCR detected 23 paternal alleles and one maternal allele. Statistical analysis by SPRT confirmed significance of the maternal allele loss. CONCLUSION: To our knowledge, this is the first molecular evidence of inactivation of both copies of the NF1 gene in a typical superficial spreading melanoma of a patient with NF1. The classical double-hit inactivation of the NF1 gene suggests that the NF1 genetic background promoted melanoma genesis in this patient

Vitamin D supplementation does not improve the severity or the resolution of ultraviolet B-induced acute erythema

Peer reviewe

Congenital infantile digital fibromatosis: a case report and review of the literature

Infantile digital fibromatosis (IDF) is a rare benign fibroproliferative tumor of early childhood. IDF preferentially affects the fingers and the toes. Malignant transformation or metastases have never been reported. Surgical treatment has been advocated previously but local recurrences were observed frequently. Recent literature supports clinical surveillance without any medical or surgical intervention as spontaneous regression usually occurs after two to three years. A six-month-old Caucasian girl with IDF on the left fourth digit is presented here. The tumor progressively increased in size after birth. Topical imiquimod cream and diflucortolone valerate cream, both displaying antifibrotic properties, had no effect on tumor growth. Currently the lesion size remains stable without any treatment. Early recognition of IDF is important in order to avoid unnecessary surgical intervention that may prove to be potentially aggravating, unless serious functional or cosmetic concerns intervene. Parents should be reassured concerning the benign nature of IDF and be informed that spontaneous involution of IDF might be expected

Acute generalized exanthematous pustulosis due to an iodinated contrast radiodiagnostic agent.

peer reviewedIodinated contrast agents are frequently involved in delayed polymorphic adverse skin reactions. Acute generalized exanthematous pustulosis following administration of iodinated contrast agents is a rare but severe form of such reactions. The disease is characterized by the sudden occurrence of an erosive and pustular erythroderma with fever, leukocytosis and sometimes peripheral adenopathies and liver involvement. This condition is considered as an immunologic reaction, primarily involving T lymphocytes. The overall mortality reaches about 1%. Elucidating the differential diagnosis with other acute paroxysmal drug eruptions (toxic epidermal necrolysis, Steven-Johnson syndrome and drug hypersensitivity syndrome) is of paramount importance for establishing the adequate treatment of PEAG

How I treat ... basal cell carcinoma by imiquimod.

peer reviewedBasal cell carcinoma is the most frequent cancer in humans. Several clinical types are distinguished. They are bound to distinct evolutive prognosis. The surgical excision is the treatment of choice which is rarely followed by recurrence. However, when the lesion is superficial and non aggressive and when the body site is adequate, topical applications of imiquimod can provoke the neoplastic regression. This type of immunotherapy brings 70 to 90% complete remission. A medical follow-up of the treated site is mandatory for a couple of years

Chronic Idiopathic Penile Edema: Three Cases and a Review of the Literature

peer reviewedAbstract: Chronic idiopathic penile edema (CIPE) is an exceptional entity with disabling persistent lymphedema of the penis, affecting accessorily the scrotum and the pubis. The onset presents with recurrent swelling of the external genitalia, regressing spontaneously. After 2-3 years the swelling becomes progressively persistent. Mictional and erectile dysfunctions are not uncommon. A thorough work-up including RX, ultrasound examination, CT scanning, MRI imaging, serology and extensive blood testing should be performed to exclude underlying causes, including neoplastic, infectious, vascular and inflammatory diseases. CIPE is associated with significant psychological and functional impact. Surgical correction is the sole therapeutic option. Three patients with CIPE and a review of the literature are presented in order to increase awareness of this rare condition

Risankizumab-Aggravated Crusted Scabies in a Patient with Down Syndrome

peer reviewedRisankizumab, an interleukin (IL)-23 antagonist, is a highly effective treatment for moderate to severe psoriasis. Crusted scabies (CS) is a rare and severe form of scabies, occurring mainly in immunosuppressed patients and/or neurologically or mentally ill patients. A young girl with Down syndrome was diagnosed with a hyperkeratotic form of psoriasis. As treatment with topical dermocorticosteroids, UVB-phototherapy and acitretin for 6 weeks did not improve the lesions, two injections of risankizumab were administered. Following these injections, the lesions became rapidly even more severely crusted, and new lesions appeared on the extremities and the face of the patient. There was histological evidence of a high charge of scabies, leading to a diagnosis of CS. The patient was hospitalized and successfully treated by local permethrine and systemic ivermectine. This case suggests that even though anti-IL23 antagonists display an excellent overall safety profile, a particular caution for infections should still be respected in patients with underlying risk factors. © 2020, The Author(s)