ABSTRACT
@#Marjolin’s ulcer is an atypical malignancy that develops from deep scars of chronically traumatised skin. Laron syndrome (LS) is a rare autosomal recessive growth retardation from a mutation in the growth hormone receptor (GHR) gene leading to defective GHR, growth hormone insensitivity and eventual low levels of insulin-like growth factor type 1 (IGF-1). Affected individuals present with proportionate dwarfism and other characteristic physical defects, but at the same time are conferred protection against cancer due to low serum levels of IGF-1. We report an exceptional case of Marjolin’s ulcer in the foot of a female LS patient 30 years after she sustained flame burns as a 6month-old baby. Three months before coming to us, she had a 2x3cm ulcer that turned into a rapidly enlarging fungating mass involving the leg, ankle, and foot. Histopathologic analysis of an incision biopsy showed well-differentiated squamous cell carcinoma. The extent of her lesion precluded wide excision. Below knee amputation was done. A second biopsy confirmed the histopathologic diagnosis. This is the first reported case in the literature of Marjolin’s ulcer in LS which raises the possibility that IGF-1 deficiency does not completely protect against squamous cell cancer.
ABSTRACT
Neste artigo são descritos os aspectos clínicos, laboratoriais e genéticos da investigação da baixa estatura, dando ênfase para o diagnóstico da insensibilidade ao hormônio de crescimento (IGH). O paciente apresentado possuía características clínicas típicas de pacientes com IGH e em idade pré-púbere seus achados laboratoriais eram compatíveis com este diagnóstico (IGF-1 e IGFBP3 baixos, GH basal e pós-estímulo elevados). No entanto, quando avaliado durante a puberdade, as dosagens de IGF-1 e IGFBP-3 foram normais, dificultando o diagnóstico. O estudo molecular identificou mutação no exon 7 do gene do receptor do hormônio de crescimento (S226I). Discutiram-se os passos realizados para identificar a mutação e demonstrar que ela é responsável pelo fenótipo observado no paciente. Também será feita revisão dos casos de IGH descritos no Brasil e dos novos defeitos moleculares descritos nesta doença.
It is reported in this study the clinical, laboratory and genetic aspects of short stature investigation with emphasis to the diagnostic approach of growth hormone insensitivity (GHI). This patient in case presented typical clinical features of GHI and his laboratory findings at prepubertal age were typical of those observed in GHI patients (low IGF-1 and IGFBP-3 levels, with high basal and stimulated GH levels). However, during the puberty, he presented normal IGFBP-3 and IGF-1 levels that hindered the diagnosis. The molecular study disclosed a mutation in exon 7 of growth hormone receptor gene (S226I). The steps that demonstrated the causative effect of this mutation are shown here, and also a review of Brazilian GHI cases is given and new molecular defects in this field are discussed as well.