Optimizing the multimodal approach to pancreatic cyst fluid diagnosis

Developing a volume-based triage protocol

Authors

  • Siaw Ming Chai MBBS, MMedSci, FRCPA,

    Corresponding author
    1. PathWest Laboratory Medicine, Queen Elizabeth II Medical Center, Nedlands, Western Australia, Australia
    • PathWest Laboratory Medicine, QEII Medical Centre, Hospital Avenue, Nedlands, Western Australia 6009, Australia

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    • Fax: (011) 61-08-9346-4122

  • Karl Herba MD,

    1. Department of Gastroenterology, Queen Elizabeth II Medical Center, Nedlands, Western Australia, Australia
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  • M. Priyanthi Kumarasinghe MBBS, MD, FRCPA, Dip Cytopathol (RCPA),

    1. School of Pathology and Laboratory Medicine, University of Western Australia, Perth, Western Australia, Australia
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  • W. Bastiaan de Boer MBBS, BMedSci, FRCPA,

    1. PathWest Laboratory Medicine, Queen Elizabeth II Medical Center, Nedlands, Western Australia, Australia
    2. School of Pathology and Laboratory Medicine, University of Western Australia, Perth, Western Australia, Australia
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  • Benhur Amanuel MD, FRCPA,

    1. PathWest Laboratory Medicine, Queen Elizabeth II Medical Center, Nedlands, Western Australia, Australia
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  • Fabienne Grieu-Iacopetta BSc,

    1. PathWest Laboratory Medicine, Queen Elizabeth II Medical Center, Nedlands, Western Australia, Australia
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  • Ee Mun Lim MBBS, FRCPA, FRACP,

    1. School of Pathology and Laboratory Medicine, University of Western Australia, Perth, Western Australia, Australia
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  • Dev Segarajasingam MBBS, FRACP,

    1. Department of Gastroenterology, Queen Elizabeth II Medical Center, Nedlands, Western Australia, Australia
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  • Ian Yusoff MBBS, FRACP,

    1. Department of Gastroenterology, Queen Elizabeth II Medical Center, Nedlands, Western Australia, Australia
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  • Chris Choo BAppSc, CMIAC,

    1. PathWest Laboratory Medicine, Queen Elizabeth II Medical Center, Nedlands, Western Australia, Australia
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  • Felicity Frost MBBS, FRCPA, FIAC, Dip Cytopathol (RCPA)

    1. PathWest Laboratory Medicine, Queen Elizabeth II Medical Center, Nedlands, Western Australia, Australia
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  • See editorial on pages 57–60, this issue.

Abstract

BACKGROUND

The objective of this study was to develop a triage algorithm to optimize diagnostic yield from cytology, carcinoembryonic antigen (CEA), and v-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) testing on different components of a single pancreatic cyst fluid specimen. The authors also sought to determine whether cell block supernatant was suitable for CEA and KRAS testing.

METHODS

Fifty-four pancreatic cysts were triaged according to a volume-dependent protocol to generate fluid (neat and supernatant) and cell block specimens for cytology, comparative CEA, and KRAS testing. Follow-up histology, diagnostic cytology, or a combined clinicopathologic interpretation was recorded as the final diagnosis.

RESULTS

There were 26 mucinous cystic lesions and 28 nonmucinous cystic lesions with volumes ranging from 0.3 mL to 55 mL. Testing different components of the specimens (cell block, neat, and/or supernatant) enabled all laboratory investigations to be performed on 50 of 54 cyst fluids (92.6%). Interpretive concordance was observed in 17 of 17 cases (100%) and in 35 of 40 cases (87.5%) that had multiple components tested for CEA and KRAS mutations, respectively. An elevated CEA level (>192 ng/mL) was the most sensitive test for the detection of a mucinous cystic lesion (62.5%) versus KRAS mutation (56%) and “positive” cytology (61.5%). KRAS mutations were identified in 2 of 25 mucinous cystic lesions (8%) in which cytology and CEA levels were not contributory.

CONCLUSIONS

A volume-based protocol using different components of the specimen was able to optimize diagnostic yield in pancreatic cyst fluids. KRAS mutation testing increased diagnostic yield when combined with cytology and CEA analysis. The current results demonstrated that supernatant is comparable to neat fluid and cell block material for CEA and KRAS testing. Cancer (Cancer Cytopathol) 2013. © 2012 American Cancer Society.

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