Pancreatic Cytopathology (eBook)

to Pancreatic Cytopathology.- Pancreatic Cytopathology: A Pragmatic Approach.- Pancreatic Ductal Adenocarcinoma and Its Variants.- Ancillary Testing for the Diagnosis of Pancreatic Ductal Adenocarcinoma.- Acinar Cell Carcinoma.- Pancreatoblastoma.- Solid-Pseudopapillary Neoplasm.- Pancreatic Endocrine Tumors.- Cystic Muscus-Producing Neoplasia: Intraductal Papillary Mucinous Neoplasms and Mucinous Cystic Neoplasms.- Other Cystic Lesions of the Pancreas.- Inflammatory Disease of the Pancreas.- Secondary Malignancies of the Pancreas.

"7 Solid-Pseudopapillary Neoplasm (p. 95-96)

Also known as solid-cystic tumor, papillary-cystic tumor, and solid and papillary tumor of the pancreas, this low-grade primary pancreatic epithelial neoplasm accounts for 1% of all exocrine pancreatic neoplasms. It occurs predominantly in adolescent girls and young women and is rare in men and children. Patients often present with vague abdominal discomfort/ pain and an enlarging abdominal mass. Not infrequently, patients are asymptomatic and the tumors are found incidentally on physical examination or by imaging for the workup for unrelated conditions.

Jaundice and hormonal disturbances are rare. Ultrasound and computed tomography (CT) usually reveal a well-demarcated and variably cystic mass, averaging 10 cm and usually located in the body or tail of the pancreas. Tumor calci? cation may be present. As smaller tumors are identi? ed with the increased use of more sensitive imaging techniques, cystic degeneration and calci? - cation are often not seen.

General Diagnostic Approach

Solid-pseudopapillary neoplasms (SPPNs) may appear either primarily solid or cystic radiologically and, as a result, one may start at different points within our algorithms. Unlike true cystic neoplasms of the pancreas, aspirates from the lesions are almost always cellular. Because the neoplastic cells of SPPN appear monotonous and less cohesive when compared to pancreatic ductal adenocarcinomas (PDAs), the cytologist usually has little problem distinguishing the two entities.

However, it can be a challenge to distinguish SPPN from other epithelioid neoplasms, such as pancreatic endocrine tumors (PETs). Because signi? cant overlap of cytologic features is often noted among these lesions and speci? c therapy may depend upon the diagnosis, one should be wary to give a de? nitive diagnosis without ancillary studies. In equivocal cases, one may choose to render a less de? nitive diagnosis such as “epithelioid neoplasm” and discuss the differential diagnosis in a note.

Diagnostic Criteria

Aspirates from these neoplasms are usually cellular and show characteristic cytologic ? ndings (Table 7-1). However, when only cystically degenerated areas are sampled, the smears may rarely be paucicellular and contain predominantly proteinaeous ? uid and/or necrotic debris, which may then result in a false-negative diagnosis. Neoplastic cells are arranged singly, in loosely cohesive clusters and in linear and branching papillary structures."