Adult pancreatoblastoma: A rare malignant tumor of the pancreas

Abstract

Pancreatoblastoma (PB) is a rare malignant tumor in adults. It has an overall incidence of 0.004 per 100,000 inhabitants. Its diagnosis with fine-needle aspiration (FNA) is difficult due to multiple differentiation lines present on PB that overlap with other tumors. A 76-year-old male patient presented with jaundice, weight loss of 10 kg in 6 months, and appetite loss. Abdominal computed tomography scan showed a tumor in the pancreas head. Transendoscopic ultrasound with FNA biopsy revealed a malignant epithelial neoplasia compatible with PB with immunohistochemistry CK19 (+), P63(+), synaptophysin (-), and Ki67 50%. The patient underwent surgical resection and adjuvant chemotherapy. Currently, the patient is in follow-up with the latest imaging showing no evidence of disease at 32 months after his initial diagnosis. PB is an uncommon malignant neoplasia with an aggressive behavior. Its diagnostic and therapeutic protocols are unclear. Its preoperative diagnosis may be difficult since its imaging features and serological markers are non-specific. However, FNA may be useful in some situations. Surgical resection is currently the recommended treatment that is associated with the best long-term survival.

Keywords: Pancreas surgery; Pancreatoblastoma; Pancreatoduodenectomy; Whipple.

Fig. 1

Abdominal computed tomography scan showing a 3.6 cm × 2.3 cm × 3 9 cm sized lesion on the pancreas head that looks (A) hypodense in the arterial phase and (B) isodense to the parenchyma in the venous phase. It loses interface with the gastroduodenal artery (arrowhead) and the celiac trunk as well as superior mesenteric artery. However, it has contacts with the right medial border of the superior mesenteric vein (arrow) without producing stenosis or thrombosis.

Fig. 2

Macroscopic evaluation (A) with smooth and yellowish lesion on the pancreatic head that presents irregular borders. Microscopic evaluation (B) showing highly cellular lobules separated by thick fibrous bands, simulating an acinar structure (H&E 4×). (C) Neoplastic cells showing an organoid arrangement around small lumina, with mild nuclear atypia, granular eosinophilic cytoplasm and abundant mitoses (H&E 40×). (D) Squamoid nests are considered as defining components, consisting of circumscribed whorled nests of plump spindle cells with a squamous appearance and keratinization (H&E 30 ×). Immunolabeling for (E) alpha1-antichymotrypsin (H&E 4×) and (F) cytokeratin 19 is highly sensible for this neoplasm (H&E 4×).