A 3-year-old boy presents to the emergency room with his parents who report that he has not had a bowel movement in the past 4 days. They also report increased irritability, inability to eat anything without vomiting, and reddish colored urine for the past two days. On physical exam, the boy has a large abdominal mass with abdominal pain on palpation. Abdominal imaging reveals intestinal obstruction secondary to the abdominal mass. Treatment is started with chemotherapy, radiation, and surgical resection of the tumor. The pathology report of the tumor is most likely to show what histological appearance?
Chromaffin cell neoplasm with accumulation of epinephrine and norepinephrine
Neoplastic cells filled with clear cytoplasm organized into round or elongated collections of cells
Small cuboid cells with round and regular nuclei
Spindle cells arranged into bands adjacent to parenchymal cells
Three distinct areas including a stromal area, small tubules, and tightly packed embryonic cells
Correct answer
Three distinct areas including a stromal area, small tubules, and tightly packed embryonic cells
correct answer: E
The patient has a Wilms Tumor that is composed of 3 distinct areas including a stromal area, an area with small tubules, and embryonic cells (choice E). This tumor usually presents between the ages of 1-3 years old and tends to be a large, bulging tumor. Additional symptoms include abdominal pain, intestinal obstruction, hypertension, and hematuria.
A chromaffin cell neoplasm with abundant epinephrine and norepinephrine (choice A) describes the histology of a pheochromocytoma. These tumors occur mainly in adults in the 4th-6th decades and are associated with paroxysmal hypertension.
Neoplastic cells filled with clear cytoplasm (choice B) describes clear cell renal carcinoma, which is unlikely given the patient’s age and presentation.
Small cuboid cells with round regular nuclei (choice C) characterizes the histology of renal adenomas, which are benign tumors that rarely metastasize. Renal adenomas increase in frequency with increasing age.
The histology of mesoblastic nephroma includes spindle cells arranged into bands next to normal parenchymal cells (choice D). This type of tumor is a congenital benign neoplasm. It is usually found in the first 3 months of life and must be differentiated from a Wilms tumor. The treatment is surgical resection, but local recurrence is common.