Fat necrosis of the newborn. / Necrosis grasa del recién nacido.

INTRODUCTION: Panniculitis is a group of diseases that affect subcutaneous fat tissue and clinically manifest as nodules. Its pathogenesis is not entirely clear, and it is usually asymptomatic. The confirma tory diagnosis is histological. OBJECTIVE: To describe the clinical and histopathological characteristics of a case of fat necrosis, a specific form of panniculitis in the newborn (NB). CLINICAL CASE: 40-week female NB, born by emergency cesarean section due to fetal tachycardia with meconium, Apgar score 7-8-9. She required oxygen and positive pressure for five minutes. On the fifth day of life, she presen ted an increased volume in the posterior trunk region, with an erythematous - purplish discoloration, which is soft and non-tender to palpation. Skin and soft tissues ultrasound showed increased echo genicity of the subcutaneous cellular tissue and loss of definition of the adipocytes of 42.3 x 9.7 x 20.1 mm approximately, without vascularization. Skin biopsy showed epidermis with irregular acanthosis and basket-weave orthokeratosis; papillary dermis with inflammatory infiltrate, and reticular dermis and adipose tissue with presence of lymphohistiocytic infiltrate with a tendency to form nodules, without vascular involvement, and small cholesterol deposits, compatible with subcutaneous fat ne crosis (SBFN) of the newborn. The patient at three months of age had complete regression of the lesion. CONCLUSIONS: a clinically and histologically compatible case with SBFN is described, that did not present complications during observation. In general, this pathology has a good prognosis, with spontaneous resolution as in our case.

Necrosis grasa del recién nacido / Fat necrosis of the newborn

Resumen: Introducción: Las paniculitis constituyen un grupo de enfermedades que afectan al tejido graso subcutáneo y se manifiestan clínicamente como nódulos. Su patogenia no es del todo clara, por lo general es asintomático. El diagnóstico confirmatorio es histológico. Objetivo: describir las características clínicas e histopatológicas de un caso de necrosis grasa, una forma especifica de paniculitis en el recién nacido (RN). Caso Clínico: RN femenino de 40 semanas, parto cesárea de urgencia por taqui cardia fetal más meconio, APGAR 7-8-9. Requirió oxigeno y presión positiva por 5 min. Al quinto día de vida presentó aumento de volumen en tronco posterior, de coloración eritematosa - violácea, remitente a la palpación, no doloroso. Ecotomografría de piel y partes blandas informó aumento de la ecogenecidad del tejido celular subcutáneo y pérdida de definición de las celdillas adiposas de aproximadamente 42.3 x 9.7 x 20.1 mm, sin presencia de vascularización. Biopsia de piel: epidermis con acantosis irregular y ortoqueratosis en cestas; dermis papilar con infiltrado inflamatorio y dermis reticular y tejido adiposo con presencia de infiltrado linfohistocitiario con tendencia a la formación de nódulos, sin compromiso vascular, leves depósitos de colesterol; compatible con necrosis grasa del recién nacido (NGRN). Paciente tuvo regresión completa de la lesión a los tres meses de vida. Conclusiones: se describe un caso compatible clínica e histológicamente con NGRN; sin complica ciones durante su observación. Por lo general esta patología tiene buen pronóstico, con resolución espontánea, como en nuestro caso.

Abstract: Introduction: Panniculitis is a group of diseases that affect subcutaneous fat tissue and clinically manifest as nodules. Its pathogenesis is not entirely clear, and it is usually asymptomatic. The confirma tory diagnosis is histological. Objective: To describe the clinical and histopathological characteristics of a case of fat necrosis, a specific form of panniculitis in the newborn (NB). Clinical Case: 40-week female NB, born by emergency cesarean section due to fetal tachycardia with meconium, Apgar score 7-8-9. She required oxygen and positive pressure for five minutes. On the fifth day of life, she presen ted an increased volume in the posterior trunk region, with an erythematous - purplish discoloration, which is soft and non-tender to palpation. Skin and soft tissues ultrasound showed increased echo genicity of the subcutaneous cellular tissue and loss of definition of the adipocytes of 42.3 x 9.7 x 20.1 mm approximately, without vascularization. Skin biopsy showed epidermis with irregular acanthosis and basket-weave orthokeratosis; papillary dermis with inflammatory infiltrate, and reticular dermis and adipose tissue with presence of lymphohistiocytic infiltrate with a tendency to form nodules, without vascular involvement, and small cholesterol deposits, compatible with subcutaneous fat ne crosis (SBFN) of the newborn. The patient at three months of age had complete regression of the lesion. Conclusions: a clinically and histologically compatible case with SBFN is described, that did not present complications during observation. In general, this pathology has a good prognosis, with spontaneous resolution as in our case.