Solid pseudopapillary tumour of pancreas

Abstract

Solid pseudopapillary tumour of the pancreas is a rare neoplasm (1%). This tumour primarily affects young women and is usually treated with surgical resection with a relatively favourable prognosis. We report an 18-year-old female patient presenting with moderate grade abdominal pain for 5 weeks. Abdominal examination revealed a lump palpable in the right upper abdomen. Contrast-enhanced CT abdomen reported soft tissue lesion arising from uncinate process of pancreas causing adjacent compression. Endoscopic ultrasound-guided fine-needle aspiration biopsy yielded a cellular sample comprising pseudopapillary arrangement with bland appearing tumour cells consistent with benign neoplasm. And because of unusual location, Whipple procedure was performed. The patient was discharged under satisfactory conditions. Final histology confirmed the diagnosis. Solid pseudopapillary tumours of the pancreas are a rare but treatable pancreatic tumour. Complete surgical excision is the treatment of choice and can be achieved through an open or minimal access technique.

Background

The solid pseudopapillary tumour (SPT) of the pancreas was first reported by Frantz in 1959. It is a rare neoplasm of low malignant potential, and accounts for approximately 1% of pancreatic tumours. This tumour primarily affects young women and is usually treated with surgical resection. After resection and follow-up, there is generally a relatively favourable prognosis. Recently, the number of cases reported in the literature has been steadily rising; however, the pathogenesis and guidelines for SPT treatment are evolving constantly.

Case presentation

An 18-year-old female patient presented in our surgical outpatient clinic with moderate grade abdominal non-colicky pain for the past 5 weeks which was episodic in nature, non-radiating and without any diurnal variation.

Investigations

On examination abdomen was flat, soft, non-tender, with a lump palpable from epigastrium extending up to the right hypochondrium, firm to hard in consistency and not moving with respiration. Haemoglobin was 9.4 g/dL and other haematological investigations were within normal limits. Abdominal ultrasound showed a large heterogeneous mass in the region of the pancreatic head. Finally, a contrast-enhanced CT abdomen revealed heterogeneously enhancing soft tissue lesion measuring approximately 5.6×6.6×6.4 cm in size arising from uncinate process of the pancreas causing buckling of the head of the pancreas with abutment and compression of inferior vena-cava and displacing the second part of the duodenum peripherally with maintained interface. Endoscopic ultrasound-guided fine-needle aspiration biopsy yielded a cellular sample comprising a pseudopapillary arrangement with bland appearing tumour cells with final cytology interpretation confirming the presence of atypical cells consistent with benign neoplasm.

Differential diagnosis

• Cystic neoplasms of the pancreas

• Carcinoma head of the pancreas

Treatment

Preoperative diagnosis of solid pseudopapillary tumour (SPT) was made. Though the cytopathology was in favour of a benign tumour but because of its difficult location and attachment with uncinate process and absence of histopathology Whipple procedure was performed (figure 1). The patient was discharged under satisfactory conditions.

Figure 1.

Resected tumour in the patient undergoing Whipple procedure (black arrow—pancreatic head cut, yellow arrow—duodenum second part, blue arrow—tumour arising from pancreatic uncinate process).

Outcome and follow-up

The histology confirmed the diagnosis of SPT of the pancreas. Immunohistochemical studies have shown that SPT was reactive for vimentin, S-100 protein and neuron-specific enolase. Adjuvant chemotherapy and radiotherapy were not offered. Post 1-year follow-up the patient is doing well.

Discussion

SPT of the pancreas is a relatively rare disease with differing opinion on management in literature.^{1 2} The origin of tumour has not been clarified and is argued that it originates either from ductal epithelium, acinar cells or endocrine cells. This tumour rarely affects men² and is characterised by a long asymptomatic course and non-specific symptoms with low malignant potential. Metastases, with an incidence of 15%, most of which are hepatic, and local recurrence have rarely been reported in the long-term follow-up of patients with SPT. The histopathological appearance is very distinctive and is considered diagnostic. It is fundamentally a solid tumour with extensive degenerative changes forming a solid cellular and hyper vascular region without glands.

Surgery is the mainstay of treatment and is usually curative for localised disease. The extent of surgery may range from simple enucleation to distal pancreatectomy and Whipple procedure depending on malignant potential and location of the tumour. A recent series from Memorial Sloan-Kettering Cancer Centre (New York, USA) recommends complete surgical excision with even metastatectomy if required.³ In this patient the tumour was attached to uncinate process and neighbouring vessel and other organs rendering enucleation very difficult.

Learning points.

• Patients usually present with slowly growing lump in the upper abdomen or may remain asymptomatic.

• It is usually found in young women.

• Surgery is the treatment of choice with good outcomes. There is always a dilemma in proper resection of tumour, that is, ranging from simple resection to Whipples procedure.

• Mostly arise from tail of the pancreas with low metastatic potential but may arise from other parts too like in our case it was arising from the uncinate process of pancreas.