Osteosarcoma metastasizing to pancreas confirmed by endoscopic ultrasound-guided fine-needle aspiration

An 18-year-old male with a history of osteosarcoma of the proximal part of the left tibia presented complaining of upper abdominal pain and vomiting. Osteosarcoma had been diagnosed 4 years previously and been treated with amputation and chemotherapy. Laboratory tests revealed mild anemia (hemoglobin 114 g/L, reference range 120 – 150 g/L), and normal serum amylase and bilirubin. Abdominal computed tomography (CT) showed a cystic–solid mass measuring 4.3 × 4.5 cm on the head of the pancreas ([Fig. 1]). Thoracic CT revealed another mass in the inferior lobe of the left lung ([Fig. 2]). No calcification was seen in either lesion. Endoscopic ultrasound (EUS) was carried out using an electronic echoendoscope (GF-UE260-AL5 for radial scanning and GF-UCT240-AL5 for linear scanning; Olympus, Tokyo, Japan) and this showed more clearly a mass containing necrotic areas in the pancreatic head and neck and a dilated pancreatic duct ([Fig. 3] and [Fig. 4]). Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) of the pancreatic mass using a 22-gauge needle (EchoTip Ultra; Cook Medical Inc., Winston-Salem, NC, USA) confirmed the diagnosis of metastatic osteosarcoma ([Fig. 5] and [Fig. 6]). Pancreatoduodenectomy and thoracotomy with resection of the left inferior lobe was then performed, followed by chemotherapy. At 7 months postoperatively the patient had recovered from the treatment and remained free of detectable disease.

Fig. 1 Abdominal CT showed a cystic–solid mass on the head of the pancreas in an 18-year-old male patient.

Fig. 2 Thoracic CT revealed another mass in the inferior left pulmonary lobe.

Fig. 3 Endoscopic ultrasound showed the mass located on the pancreatic head and neck and a dilated pancreatic duct. pan, pancreas, pd, pancreatic duct, sv, splenic vein, con, confluence, sma, superior mesenteric artery.

Fig. 4 Endoscopic ultrasound clearly showed the pancreatic mass containing necrotic areas.

Fig. 5 Endoscopic ultrasound-guided fine-needle aspiration of the pancreatic mass with a 22-gauge needle.

Fig. 6 Histopathologic analysis revealed amorphous pink-colored osteoid structures with pleomorphic multinucleated sarcomatoid cells.

Osteosarcoma possesses a high potential for metastasis. The most common sites of metastatic osteosarcoma are the lung, pleurae, and bone. Metastasis to the pancreas is extremely rare [1], and pulmonary metastases usually occur before pancreatic metastases [2]. Our case demonstrates that EUS-FNA is a useful method for definitive diagnosis of pancreatic metastasis in a patient with a history of extrapancreatic malignancy.

Endoscopy_UCTN_Code_CCL_1AF_2AZ

Competing interests: None

• References

• 1 Avcu S, Akdeniz H, Arslan H et al. A case of primary vertebral osteosarcoma metastasizing to pancreas. J Pancreas (Online) 2009; 10: 438-440
• 2 Aarvold A, Bann S, Giblin V et al. Osteosarcoma metastasising to the duodenum and pancreas. J Bone Joint Surg [Br] 2007; 89: 542-544