A 9-day old male newborn infant was admitted in our hospital with history of poor feeding, vomiting, decreased tonicity, lethargy, and dehydration since two days before. He was the second-born child of non consanguineous parents. His mother had history of polyhydramnios. He was the product of caesarian section because of polyhydramnios. Birth weight was 3700 g, Apgar scores were normal and he was discharged at the first day of age.
On admission findings were as follows: heart rate 143/min, respiratory rate 52/min, blood pressure (BP) 140/110 mmHg, weight 2.30 kg. He had lost 1400 g since birth and had a mild degree of hypotonia and hyporeflexia.
Physical examination revealed a large right-sided abdominal mass with regular margins (Fig ). Ultrasound examination showed a large echogenic and heterogeneous mass composed cystic areas that was 85 × 65 mm confirmed.
The figure shows the huge abdominal mass dominant in right side.
Initial biochemical studies revealed serum calcium of 17 mg/dl (reference range 8.2-10.5 mg/dl). He had persistent hypercalcemia (serum calcium > 15 mg/dl) for more than 6 hours before medical therapy. Other laboratory tests were in normal ranges and serum Phosphorus and magnesium were 3.8 mg/dl and 2 mg/dl respectively.
At first visit we tried normal saline and furosemide but no obvious response was seen. Then the patient received two intravenous pamidronate (1.5 mg/kg) for 2 days. Pamidronate infused in 25 milliliter of 5% dextrose saline solution over 4 hours. His serum calcium level decreased significantly, and about 18 hours later, his total calcium level normalized and his symptoms recovered except abdominal mass. Because our patient was hypertensive, we prescribed nifedipine also. Unfortunately we do not have the levels of serum PTH and specific markers of bone turnover because were not measured.
After stabilization of hypercalcemia, successful right nephrectomy was performed.
Histological evaluation of revealed a well circumscribed, 11 × 10 × 8 cm, round shape, smooth yellow mass in the upper pole of the right kidney (Fig ). On the microscopic examination the lesion displayed bundles of spindle shaped stromal cells with occasional entrapped normal renal tubular and glomerular cell, findings that consistent with diagnosis of mesoblastic nephroma (Fig ). After operation serum calcium level doesn't increase again. The normal blood pressure achieved about 16 hours after operation.
Hematoxiline and eosin staining of the tumor specimen showed bundles of spindle shaped stromal cells with occasional entrapped normal renal tubular and glomerular cell. (1000×).