Isotretinoin is an oral derivate of vitamin A that has been used since 1982 for the treatment of multiple dermatologic conditions such as severe acne, rosacea, scarring alopecia, ichthyosis or non-melanoma skin cancer prophylaxis. The recommended dose is 0.5-1 mg/kg/day for a period of 4-6 months in sebaceous gland pathologies. There are many adverse effects caused by isotretinoin but by far the most important is the teratogenicity induced by this drug which is estimated to have a 20-35% risk to infants that are exposed to isotretinoin in utero and includes numerous congenital defects such as craniofacial defects, cardiovascular and neurological malformations or thymic disorders. Isotretinoin induces apoptosis and cell cycle arrest in human sebocytes, emphasizing these as processes associated with its teratogenic effect. The aim of this review is to analyze the latest literature data regarding the teratogenic effect of isotretinoin for both fertile females and males and its biological effects underlying the occurrence of congenital malformations under the influence of isotretinoin.

Regressive melanoma is a phenomenon characterized by partial or complete replacement of cutaneous melanoma by fibrotic structures as a result of local host immune response. The dermoscopic features include 'scar-like' depigmentation that can be described as hypopigmented to pigmented macules, pink macules, linear-irregular vessels, globular vessel pattern, hyperpigmented macular remnants, blue gray 'peppered' papular remnants and white transverse bands. Fully regressive melanoma is very rare, and, in majority of cases, the tumor is associated with metastases, so the prognosis is very poor due to this fact. Regressive melanomas are rare since it represents an advance stage of melanoma evolution. Their treatment requires a collaboration between the dermatologist and the oncologist in order to improve the quality of life of the patient and also the survival rate.Abbreviations: UV, ultraviolet; MxA, myxovirus resistance A; CXCR3, chemokine receptor; iP10/CXCl10, interferon-γ-induced protein/C-X-C motif chemokine 10; Cd68, cluster of differentiation 68; iCAm-1, intercellular adhesion molecule-1