Horváth Emőke, Gozar H, Chira Liliana, Dunca Iulia, Kiss Eva, Pávai Z
Department of Pathology, University of Medicine and Pharmacy of Tirgu Mures, Romania;
Rom J Morphol Embryol. 2013;54(4):1147-51.
Solitary insulinoma is a rare pancreatic tumor in all age groups with an estimated incidence of 1 in 250 000 persons a year. It is even rarely in childhood and mostly shows benign behavior. Cases with uncertain or malignant biology are extremely rare with less than 30 cases described in the literature. Here we report a case of pediatric insulinoma, the first in our department files in the past 20 years, with rapid clinical course following a clinical misdiagnosis as juvenile myoclonic epilepsy, which was complicated with low glucose level (20 mg/dL) and neuroglycopenia. Our case underlines some unusual features of a pediatric insulinomas presented without past medical and family history, after surgery complicated with mental retardation and recurrent epileptiform episodes. Despite the small tumor size, low Ki67 index/mitotic rate and benign immunophenotype marked by positivity for pro-insulin but negativity for β-HCG, the diagnosis was concluded as insulinoma of uncertain biological behavior due to vascular tumor invasion in agreement with the 2003 WHO Classification for Pancreatic Endocrine Neoplasms. Besides these features, perineural invasion can differentiate insulinomas of uncertain outcome from benign insulin producing tumors. Pediatric insulinomas may present misleading symptoms of epilepsy in neglected cases coming from poor socioeconomic background. Chronic insufficient blood glucose level might contribute to mental retardation and epilepsiform myoconvulsions to be prevented. Differentiation between insulinoma with benign and uncertain behavior is difficult where histological pattern and tumor immunophenotype are less important than the critical morphological parameters. Life long follow-up including regular control of blood glucose and abdominal status of patients are essential for proper assessment of clinical outcome of pediatric insulinoma.
孤立性胰岛素瘤在所有年龄组中都是一种罕见的胰腺肿瘤，估计每年发病率为1/250000。在儿童期更为罕见，且大多表现为良性。生物学行为不确定或恶性的病例极为罕见，文献报道不足30例。在此，我们报告一例儿童胰岛素瘤，这是我们科室过去20年档案中的首例，临床误诊为青少年肌阵挛性癫痫后临床病程进展迅速，伴有低血糖水平（20mg/dL）和神经低血糖症。我们的病例突显了儿童胰岛素瘤的一些不寻常特征，该病例无既往病史和家族史，术后并发智力发育迟缓及反复癫痫样发作。尽管肿瘤体积小，Ki67指数/有丝分裂率低，免疫表型呈良性，胰岛素原阳性而β-HCG阴性，但根据2003年世界卫生组织胰腺内分泌肿瘤分类，由于肿瘤侵犯血管，诊断为生物学行为不确定的胰岛素瘤。除这些特征外，神经周围侵犯可将预后不确定的胰岛素瘤与良性胰岛素分泌肿瘤区分开来。来自社会经济背景差的被忽视病例中，儿童胰岛素瘤可能表现出误导性的癫痫症状。慢性血糖水平不足可能导致智力发育迟缓和癫痫样肌阵挛，应予以预防。在组织学模式和肿瘤免疫表型不如关键形态学参数重要的情况下，区分良性和行为不确定的胰岛素瘤很困难。对患者进行终身随访，包括定期监测血糖和腹部状况，对于正确评估儿童胰岛素瘤的临床结局至关重要。
