Pamidronate therapy for hypercalcemia and congenital mesoblastic nephroma: a case report

Report and follow-up on two new patients with congenital mesoblastic nephroma

BACKGROUND

Tumors are rare in neonatal age. Congenital mesoblastic nephroma (CMN) is a usually benign renal tumor observed at birth, or in the first months of life. It may also be identified prenatally and associated with polyhydramnios leading to preterm delivery. Effective treatment is surgical in most cases, consisting in total nephrectomy. In literature, very few studies report on the neonatal management of such a rare disease, and even less are those describing its uncommon complications.

CASES PRESENTATION

We report on two single-center newborns affected with CMN. The first patient is a preterm female baby, born at 30+ 1 weeks of gestation (WG) due to premature labor, with prenatal (25 WG) identification of an intra-abdominal fetal mass associated with polyhydramnios. Once obtained the clinical stability, weight gain, instrumental (computed tomography, CT, showing a 4.8 × 3.3 cm left renal neoformation) and histological/molecular characterization of the lesion (renal needle biopsy picture of classic CMN with ETV6-NTRK3 translocation), a left nephrectomy was performed at 5 weeks of chronological age. The following clinical course was complicated by intestinal obstruction due to bowel adherences formation, then by an enterocutaneous fistula, requiring multiple surgical approaches including transitory ileo- and colostomy, before the conclusive anastomoses intervention. The second patient is a 17-day-old male term baby, coming to our observation due to postnatal evidence of palpable left abdominal mass (soon defined through CT, showing a 7.5 × 6.5 cm neoformation in the left renal lodge), feeding difficulties and poor weight gain. An intravenous diuretic treatment was needed due to the developed hypertension and hypercalcemia, which regressed after the nephrectomy (histological diagnosis of cellular CMN with ETV6-NTRK3 fusion) performed at day 26. In neither case was chemotherapy added. Both patients have been included in multidisciplinary follow-up, they presently show regular growth and neuromotor development, normal renal function and no local/systemic recurrences or other gastrointestinal/urinary disorders.

CONCLUSIONS

The finding of a fetal abdominal mass should prompt suspicion of CMN, especially if it is associated with polyhydramnios; it should also alert obstetricians and neonatologists to the risk of preterm delivery. Although being a usually benign condition, CMN may be associated with neonatal systemic-metabolic or postoperative complications. High-level surgical expertise, careful neonatological intensive care and histopathological/cytogenetic-molecular definition are the cornerstones for the optimal management of patients. This should also include an individualized follow-up, oriented to the early detection of any possible recurrences or associated anomalies and to a better quality of life of children and their families.

Use of Calcitonin for Hypercalcemia in a Premature Neonate With Congenital Mesoblastic Nephroma

We report on a premature neonate (31 4/7 weeks' gestation) who presented with hypercalcemia secondary to congenital mesoblastic nephroma (CMN), the most common type of renal tumor in neonates. Typical presentation includes a palpable abdominal mass or swelling and may include abdominal pain, hematuria, fever, or hypertension. A less common complication of CMN is hypercalcemia of malignancy. Although the primary management strategy for hypercalcemia of malignancy is to treat the underlying disease, there are several agents that can be used as well for acute hypercalcemia including fluids, loop diuretics, corticosteroids, bisphosphonates, and calcitonin. However, there is minimal evidence to guide efficacious and safe treatment selection and dosing as hypercalcemia is a rare complication of this tumor type. This case adds to the current body of literature as only the second case of parathyroid hormone-related peptide-mediated hypercalcemia in a preterm neonate treated with calcitonin and is the first to specify a successful dose escalation strategy of calcitonin for this indication.

Neonatal congenital mesoblastic nephroma that caused respiratory oncologic emergency early after birth: a case report

BACKGROUND

Congenital mesoblastic nephromas mainly present as asymptomatic abdominal masses, but some present hematuria, hypertension or hypercalcemia. Neonatal dyspnea in an early-birth neonate due to rapid tumor growth is reported here for the first time.

CASE PRESENTATION

A renal tumor and polyhydramnios were detected by ultrasonography of a male fetus at 32 weeks and 3 days of gestation. The mother had abdominal distension due to the polyhydramnios and signs of imminent premature birth. Amniocentesis was performed and the signs of imminent preterm birth subsided, but growth of the renal tumor was noted as a potential cause of respiratory dysfunction. Cesarean section was performed at 36 weeks and 2 days of gestation. His birthweight was 2638 g and his 1 and 5 min APGAR scores were 2 and 4 points, respectively. There was no spontaneous breathing at birth and he had remarkable abdominal distention. He underwent cardiopulmonary resuscitation. After circulation stabilized, emergency surgery was performed because of progressive hypoxemia and respiratory acidosis. Laparotomy revealed a huge tumor arising from the right kidney and right nephrectomy was performed. Histopathological examination led to diagnosis of congenital mesoblastic nephroma. The respiratory condition and circulatory dynamics stabilized after the pressure on the thorax from the tumor was relieved by surgery. The postoperative course was uneventful. No recurrence or complications have been observed in the 36 months since the surgery.

CONCLUSIONS

Congenital mesoblastic nephroma can rapidly increase in size from the fetal period and may cause respiratory oncologic emergency, although there is relatively good prognosis.

Review of paraneoplastic syndromes in children

Paraneoplastic syndromes are defined as clinical syndromes that are not related to direct tumor invasion or compression but are secondary to tumor secretion of functional peptides/hormones or related to immune cross-reactivity with normal host tissue. Paraneoplastic syndromes have a wide range of presentations and can present before the primary malignancy or tumor recurrence is diagnosed. They can mimic non-neoplastic processes, making detection, diagnosis and treatment difficult. However, they can also provide clues to the presence of an underlying malignancy. In this paper, we reviewed a range of paraneoplastic syndromes that can occur in children including: (1) neurologic (opsoclonus-myoclonus, limbic, anti-N-methyl-d-aspartate [NMDA] and anti-Ma2 encephalitis and myasthenia gravis); (2) endocrine (neuroendocrine tumors, hypercalcemia, SIADH [syndrome of inappropriate antidiuretic hormone secretion], osteomalacia/rickets and ROHHAD [rapid onset of obesity, hypoventilation, hypothalamic dysfunction and autonomic dysregulation]); and (3) dermatologic/rheumatologic syndromes (hypertrophic osteoarthropathy and paraneoplastic pemphigus). Familiarity with these syndromes can aid in early diagnosis, treatment and imaging optimization.

Two cases of humoral hypercalcemia of malignancy complicating infantile fibrosarcoma

We report two infants with infantile fibrosarcoma (IFS) complicated by severe hypercalcemia. Assessment demonstrated suppressed parathyroid hormone and 1,25-dihydroxyvitamin D levels with elevated circulating levels of parathyroid hormone related protein, indicating the diagnosis of humoral hypercalcemia of malignancy (HHM). HHM is a paraneoplastic syndrome rarely associated with pediatric malignancies. Hypercalcemia manifested clinically with neurologic symptoms and soft tissue calcium deposition and required aggressive management with intravenous fluids, diuretics, and supplemental electrolytes. Following treatment with neoadjuvant chemotherapy, serum calcium levels precipitously declined requiring calcium repletion. These cases highlight the improvement of hypercalcemia secondary to HHM following chemotherapy.

Congenital mesoblastic nephroma 50 years after its recognition: A narrative review

Congenital mesoblastic nephroma (CMN) is a rare pediatric renal tumor with low malignant potential that most commonly occurs early in infancy. Treatment strategies are based on the few published CMN series, while a significant number of CMN patients have been described in case reports. The aim of this narrative review was to create an up-to-date overview of the literature. Complete surgical removal is curative in most cases. The risk of treatment-related mortality (both surgery- and chemotherapy-related) is relatively high in the first weeks of life, indicating that these young patients deserve special attention with respect to timing and type of treatment.