ESPE Abstracts

Introduction: Wilms tumor is the most frequent pediatric renal malignancy and its usual presentation is an abdominal mass or hematuria. Unusual presentations have also been reported, such as paraneoplastic syndromes (acquired von Willebrand disease, sudden death due to pulmonary embolism and Cushing syndrome). These conditions can precede, occur concomitantly or present in a later phase of tumor development. Precocious puberty, as paraneoplastic endocrine syndrome, has already been described in children with malignant tumors (brain, gonadal, adrenal tumors and hepatoblastoma). However, little is known about central precocious puberty, as paraneoplastic manifestation of nephroblastoma or secondary to its specific chemotherapy.

Case presentation: Here, we report a case of Wilms tumor and simultaneous precocious puberty in a 5-year-old girl. She presented with macroscopic hematuria and abdominal pain. Her personal and familial medical history were unremarkable. On physical examination a mass in the right upper quadrant was palpated. She had bilateral breast buds, corresponding to stage 2 of the Tanner classification and no other pubertal signs. The first diagnosis was nephroblastoma stage I and simultaneous premature telarche, confirmed by the pre pubertal levels of luteinizing (LH) and follicular stimulating hormone (FSH), and estradiol.

The oncological protocol was commenced, with complete excision of the tumor and chemotherapy cycles over 3 months.

A second endocrine assessment was performed at the end of chemotherapy. An accelerated linear growth (a gain of 3 cm in 4 months) and a rapid breast development (passage from stage 2 to stage 3) with no axillary or pubic hair were noted. The hormonal work-up found an activated pituitary-gonadal axis along with advanced skeletal maturation and ultrasound signs of uterine hormonal impregnation. The human chorionic gonadotropin (hCG) levels were normal. Brain magnetic resonance imaging showed a morphologically normal pituitary, but of pubertal size and no congenital or acquired lesions in the pineal or hypothalamic-optic region. The definitive diagnosis of idiopathic central precocious puberty (CPP) was made and the treatment with GnRH agonist was started.

Conclusion: An interesting point to consider is whether the CPP in our case represented a coincidental finding.

Collating data from the literature review relating to the proposed pathophysiological mechanisms underlying paraneoplastic syndrome and neoplasia-induced pubertal activation, and considering this alongside our patient's clinical evolution, we finally established that the association between Wilms tumor and CPP was purely coincidental.