ABSTRACT
Background: Melanoma is an aggressive cutaneous cancer. Acral lentiginous melanoma is a melanoma subtype arising on palms, soles, and nail-units. The incidence, prevalence and prognosis differ among populations. The link between expression of major histocompatibility complex Class II alleles and melanoma progression is known. However, available studies report variable results regarding the association of melanoma with specific HLA Class II loci. Aims: The aim of the study was to determine HLA Class II allele frequencies in acral lentiginous melanoma patients and healthy Mexican Mestizo individuals. Methods: Eighteen patients with acral lentiginous melanoma and 99 healthy controls were recruited. HLA Class II typing was performed based on the sequence-specific oligonucleotide method. Results: Three alleles were associated with increased susceptibility to develop acral lentiginous melanoma, namely: HLA-DRB1*13:01; pC = 0.02, odds ratio = 6.1, IC95% = 1.4–25.5, HLA-DQA1*01:03; pC = 0.001, odds ratio = 9.3, IC95% = 2.7–31.3 and HLA-DQB1*02:02; pC = 0.01, odds ratio = 3.7, IC95% = 1.4–10.3. Limitations: The small sample size was a major limitation, although it included all acral lentiginous melanoma patients seen at the dermatology department of Dr. Manuel Gea González General Hospital during the study period. Conclusion: HLA-DRB1*13:01, HLA-DQB1*02:02 and HLA-DQA*01:03 alleles are associated with increased susceptibility to develop acral lentiginous melanoma in Mexican Mestizo patients.
ABSTRACT
Resumen Introducción: la neurofibromatosis es un desorden genético, que afecta el crecimiento de tejidos neurales, con una incidencia de 1 en 4 000 personas, con impacto en la esperanza de vida por su asociación con neoplasias y enfermedad vascular. La neurofibromatosis segmentaria es una variante de la neurofibromatosis tipo 1, con una incidencia aproximada de 1 en 20 000 a 25,000 personas, se caracteriza por lesiones cutáneas que afectan un segmento corporal sin cruzar la línea media. Generalmente no tienen historia familiar ni compromiso sistémico. Caso clínico: paciente de sexo femenino de 63 años con dermatosis que afecta el tronco posterior de manera unilateral a nivel de los dermatomas T10-T11, caracterizada por múltiples neoformaciones exofíticas milimétricas en forma de domo, de consistencia blanda y depresibles a la palpación. El estudio histopatológico de una de ellas confirmó el diagnóstico de neurofibroma. La paciente no presentaba afectación neurológica ni ocular, además, sin afección en familiares, por lo que se establece diagnóstico de neurofibromatosis segmentaria. Conclusiones: la neurofibromatosis segmentaria es una patología poco frecuente, Aunque posiblemente sea subdiagnosticada por su carácter asintomático, lo que ocasiona una aparente baja incidencia. Los pacientes que la padecen pueden presentar penetrancia sistémica variable y un riesgo similar de neoplasias al descrito en pacientes con neurofibromatosis tipo 1. Pese al carácter benigno reportado en la literatura sugerimos un abordaje multidisciplinario de los pacientes.
Abstract Introduction: neurofibromatosis is a genetic disorder that affects the growth of neural tissues, with an incidence of 1 in 4 000, with impact on life expectancy due its association with neoplasms and vascular disease. segmental neurofibromatosis is a subtype of neurofibromatosis type 1, with an approximate incidence of 1 in 20 000 to 25 000 people, it is characterized by skin lesions that affects a body segment without crossing midline, they generally have no family history or systemic involvement. Clinical case: a 63-year-old female patient with dermatosis affecting the posterior trunk unilaterally at the level of dermatomes t10-t11, characterized by multiple exophytic, dome-shaped, millimeter sized neoformations, soft in consistency and depressible on palpation. the histopatologic study of one of them confirmed the diagnosis of neurofibroma. the patient did not present neurological or ocular involvement, without affection in relatives. diagnosis of segmental neurofibromatosis was made. Conclusions: segmental neurofibromatosis is a rare pathology, although it is possibly underdiagnosed due its asymptomatic nature, which causes an apparent low incidence. patients may present variable systemic penetrance and a similar risk of neoplasm compared to patients with neurofibromatosis type 1. despite the benign nature reported in the literature, we suggest a multidisciplinary approach to patients.