Paraneoplastic manifestations in children

Anti-CV2/Collapsin Response Mediator Protein 5 (CRMP5) Paraneoplastic Encephalitis Induced by Small Cell Lung Cancer

Paraneoplastic neurological syndrome (PNS) associated with anti-CV2/CRMP5 antibodies is a rare entity that can present in various clinical manifestations, from encephalitis to chorea, depending on the brain region involved. We report a case of an elderly person with small cell lung cancer who presented with PNS encephalitis associated with anti-CV2/CRMP5 antibodies which were confirmed on immunological analysis.

Ectopic parathyroid hormone as a rare aetiology of hypercalcemia with rhabdomyosarcoma: a new treatment strategy with zoledronic acid and Denosumab

OBJECTIVES

Ectopic parathyroid hormone (PTH) secretion is rare in children with rhabdomyosarcoma, and only a few pediatric cases have been reported to date. Reports of the use of zoledronic acid (ZA) and Denosumab are limited for the treatment of hypercalcemia of malignancy (HCM) in the pediatric population. The aim of presenting this pediatric case of rhabdomyosarcoma accompanied by HCM, secondary to ectopic PTH secretion, was to highlight the benefits of ZA as a first-choice bisphosphonate in this situation with Denosumab as an alternative therapy.

CASE PRESENTATION

The patient was diagnosed at 13 years with alveolar rhabdomyosarcoma. Multiple bone metastases first appeared at 15 years, but he remained normocalcemic until 17 years old when serum calcium was 15.1 mg/dL and PTH 249 pg/mL. While serum calcium responded well after ZA and Denosumab cycles, PTH remained elevated, reaching a peak value of 1851 pg/mL during treatment cycles.

CONCLUSIONS

We report a patient with rhabdomyosarcoma accompanied by HCM, secondary to ectopic PTH, in whom the HCM was successfully managed with ZA and Denosumab. We believe that ZA should be the bisphosphonate of choice in pediatric HCM with rhabdomyosarcoma, while Denosumab may be another option in ZA-refractory cases.

Ectopic ACTH Secretion in a Child With Metastatic Ewing's Sarcoma: A Case Report

Ectopic ACTH syndrome is rare in pediatric age. Sarcomas that cause Ectopic ACTH Syndrome (EAS) are even more uncommon. Currently, only three cases of EAS caused by Ewing' sarcoma have been reported. We detail a 10-year-old boy with Cushing's syndrome symptoms caused by ectopic ACTH production by a metastatic Ewing's sarcoma of the right ischio-pubic and ileo-pubic branches. The rapid appearance of cushingoid symptoms, with significant weight gain, acne, hirsutism, and hypercortisolism were implications of ectopic ACTH production as paraneoplastic Cushing's Syndrome. The very high levels of ACTH and non-suppression at the high dose dexamethasone test confirmed the clinical suspicion. We underline the possibility EAS was caused by an ACTH-secreting tumor, including soft tissue sarcomas.

Paraneoplastic Limbic Encephalitis Associated with Anti-CV2/CRMP5 Antibodies Secondary to Thymoma in an Adolescent

Paraneoplastic neurological syndromes (PNS) associated with anti-CV2/CRMP5 antibodies are rare in the literature. Various clinical manifestations can occur including paraneoplastic limbic encephalitis (PLE). Thymoma is one of the rare causes that can be associated with this syndrome. It has not been reported in the literature in children or adolescents to the best of our knowledge. We report a case of PLE in a 19-year-old male patient secondary to thymoma that was diagnosed after 5 years of onset. Anti-CV2/CRMP5 antibodies were positive in the serum and became negative after thymectomy. Diagnosis of PNS should be evoked in cases with atypical neurological manifestation and can be confirmed by the presence of onconeuronal antibodies. We report the first pediatric PLE secondary to thymoma associated with anti-CV2/CRMP5 antibodies.

Hypercalcaemia secondary to ectopic parathyroid hormone expression in an adolescent with metastatic alveolar rhabdomyosarcoma

We report the case of a 14-year-old male with metastatic alveolar rhabdomyosarcoma, presenting with hypercalcaemia (3.89 mmol/l) and elevated parathyroid hormone (PTH) level (10.2 pmol/l). Imaging demonstrated extensive bony lytic damage, with "floating teeth" in the mandible. Normalisation of calcium levels and bony reformation of the mandible occurred following chemotherapy; PTH levels decreased initially but remained above normal levels. Imaging did not demonstrate any evidence of parathyroid abnormality. Tumour ectopic PTH secretion is a very rare cause of hypercalcaemia of malignancy in children. Hypercalcaemia with an elevated PTH, in the absence of parathyroid-related cause, should prompt investigation for underlying malignancy.

Neoplastic causes of abnormal puberty

BACKGROUND

Neoplasm-related precocious puberty (PP) is a rare presenting feature of childhood cancer. Moreover, evaluation of suspected PP in a child is complex, and cancer is often not considered. We characterized the clinicopathologic features of patients presenting with PP at a large pediatric cancer center, reviewed the relevant literature, and developed an algorithm for the diagnostic work-up of these patients.

METHODS

We examined the records of all patients with a neoplasm and concomitant PP treated at St. Jude Children's Research Hospital from January 1975 through October 2011, reviewed the available literature, and analyzed the demographic, clinical, endocrine, and neoplasm-related features.

RESULTS

Twenty-four of 13,615 children and adolescents (0.18%) were diagnosed with PP within 60 days of presentation. Primary diagnoses included brain tumor (12), adrenocortical carcinoma (5), hepatoblastoma (4), and others (3). PP was observed 0-48 months before diagnosis of neoplasm; 17 patients had peripheral PP and 7 had central PP.

CONCLUSIONS

Neoplasm-related PP is rare and takes the form of a paraneoplastic syndrome caused by tumor production of hormones or by alteration of physiologic gonadotropin production. PP can precede diagnosis of malignancy by months or years, and neoplastic causes should be considered early to avoid delayed cancer diagnosis. Treatment of the primary malignancy resolved or diminished PP in surviving patients with an intact hypothalamic-pituitary-gonadal axis.