|Pancreatic Pathology Online
Pathology of Solid-Pseudopapillary Tumour of the Pancreas
Dr Sampurna Roy MD June 2016
and cystic tumour of the pancreas ;
and papillary epithelial neoplasm.
Solid-pseudopapillary tumour was first described by Frantz in 1959.
It is a rare tumour which has a low-grade malignant potential.
Clinical presentation:This uncommon tumour occurs almost exclusively in adolescent girls and young women with a median age of 26 years.
Rare cases have been reported in men.
It appears to be more aggressive in older males.
Patients usually present with an enlarging and painful abdominal mass, but asymptomatic cases are found incidentally at laparotomy or by imaging technique.
The diagnosis depends on histologic confirmation, but its appearance on imaging is fairly characteristic, being a large well-encapsulated mass with calcification and areas of hemorrhagic degeneration.
Gross features:Grossly, the tumour may occur anywhere in the pancreas as a round, well- circumscribed lesion, measuring 2-17 cm in diameter (average 8 cm).
Cut surface shows a solid mass with cystic zones. Areas of necrosis and hemorrhage are common.
Microscopic features: The histological appearance is very distinctive and is considered diagnostic.
1. The solid portion is composed uniform, small and round cells arranged in sheets, cords and trabeculae with a rich vascular network.
The cytoplasm is eosinophilic or vacuolated, often containing PAS-positive droplets.
Nuclei are round or ovoid, having finely dispersed chromatin and inconspicuous nucleoli.
Mitoses are few. Many of the cells, farthest from the vessels undergo degeneration and death causing remaining cells around the vessels to form pseudorosette mimicking endocrine tumour.
2. The cystic zones result from more degenerative changes with prominent necrosis and hemorrhage.
Cholesterol granulomas may be present.
3. Malignant forms show vascular and nerve sheath invasion.
Tumours show positive immunostaining for alpha-1-antitrypsin, alpha-antichymotrypsin, neuron-specific enolase, and vimentin.
Positive immunostaining for progesterone nuclear receptor antibody has been reported.
One recent case shows a distinctive, unbalanced translocation between chromosomes 13 and 17.
Majority of the tumours have a borderline malignant potential, but most patients are symptom-free many years after surgery.
Frankly malignant tumors are characterized by vascular invasion and/or metastases to lymph nodes or liver.
Surgical resection has generally been curative, but close follow up is advisable, particularly when the histologic characteristics suggest a more aggressive tumour.
Differential diagnosis: Any solid or cystic pancreatic disease entities, such as - mucinous cystic tumor, microcystic adenoma, islet cell tumor, cystadenocarcinoma, acinar cell carcinoma, inflammatory pseudocyst, mucus secreting tumour, pancreatoblastoma, and a vascular tumor-like hemangioma.
The first four are usually seen in older patients and have no particular gender preponderance.
Pancreatoblastoma is usually found in younger individuals of either sex.
Radiologically, a linear sunburst pattern of calcification is the usual finding in microcystic adenoma.
A hypervascular pattern on angiography is suggestive of islet cell tumour rather than solid-pseudopapillary tumour.
Cytologic features of solid pseudopapillary neoplasms of the pancreas: a single institutional experience based on evaluation of diagnostic utility of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA).
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