Chhieng / Stelow Pancreatic Cytopathology

1. Auflage 2010
ISBN: 978-0-387-68947-0
Verlag: Springer
Format: PDF
Kopierschutz: 1 - PDF Watermark

E-Book, Englisch, Band 3, 197 Seiten

Reihe: Essentials in Cytopathology

Diagnosis by cytologic means is what the mathematicians would describe as elegant; the methods are often simple but richly nuanced, while the results can be profound though succinctly stated. Tiny samples atraumatically obtained are at the heart of both the elegance and the dif? culties of this subspecialty. Following initial successes of traditional exfoliative cytology, further applications were long constrained by the fact that few body surfaces present themselves for direct collection of exfo- ated cells. Thus, it was inevitable that advances in nonoperative evaluations for speci? c body sites would be accompanied by expansions in cytologic diagnosis. Hence the proliferation of sampling methods with techniques the same as their names, including brushing, washing, lavage, and aspiration. Examples come readily to mind. One of the most dramatic bursts in cytodiagnosis happened in the 1980s, when deep-lung sampling by bronchoalveolar lavage (BAL) arrived at about the same time as the AIDS pandemic. Frequent and often repeated diagnosis of CMV and pneumocystis quickly led to numerous such samples being submitted to many laboratories. These now common infectious agents and this new technique were highly suited to rapid evaluation of AIDS patients. The rapid rise of ? ne needle aspiration occurred at about the same time, at least on this side of the Atlantic. Although not really new, the explosion in its use had awaited both cli- cal acceptance and adequate training for a critical mass of pathologists. This history has been well recorded by others.

Autoren/Hrsg.

Chhieng, David C.

Stelow, Edward B.

Leseproben

" (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."