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Everything you need to know about Computed Tomography (CT) & CT Scanning

Pancreas: Ipmn Imaging Pearls - Educational Tools | CT Scanning | CT Imaging | CT Scan Protocols - CTisus
Imaging Pearls ❯ Pancreas ❯ IPMN

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  • “IPMNs are cystic neoplasms with variable degree of malignant potential. They may evolve into dysplasia or invasive carcinoma and are associated with a higher risk for the development of PDAC in the gland separate from the IPMN sites. The rate of progression increases with time. Low-risk IPMNs have an approximately 8% chance of progression, whereas higher risk IPMNs have an approximately 25% chance of progression to PDAC in 10 years. Even presumed low- risk BD-IPMNs may demonstrate growth after 5 years.”
    Incidental Pancreatic Cysts on Cross-Sectional Imaging  
    Shannon M. Navarro et al.
    Radiol Clin N Am 59 (2021) 617–629 
  • OBJECTIVE. The purpose of this study is to retrospectively evaluate the differential CT features of isolated benign and malignant main pancreatic duct (MPD) dilatation and to investigate whether the diagnostic performance of radiologists can be improved with knowledge of these differential CT features. 


    CONCLUSION. Distal, long (≥ 6.1 mm), and abrupt transition, the absence of duct penetrating sign, and the presence of attenuation difference and PD or CBD enhancement were highly suggestive CT ndings for differentiation of malignant from benign MPD dilatation. The diagnostic performance of radiologists with regard to differentiation was signi cantly improved with knowledge of these highly suggestive CT criteria.


    Isolated Main Pancreatic Duct Dilatation: CT Differentiation Between Benign and Malignant Causes 
Se Woo Kim et al 
AJR 2017; 209:1046–1055

  • “In a 2013 study of the National Cancer Institute (NCI) Surveillance, Epidemiology, and End Results (SEER) registry, the estimated number of pancreatic cysts in the U.S. population between 40 and 84 years old was 3,428,874, with an overall cyst prevalence of 2.5%. Increased use of cross-sectional imaging has led to increased detection of such cysts in recent years; 2.2% of upper abdominal CT examinations and 19.6% of MRI examinations report a pancreatic cyst .”


    Management of Incidental Pancreatic Cysts: A White Paper of the ACR Incidental Findings Committee.
Megibow AJ et al. 
 J Am Coll Radiol. 2017 Jul;14(7):911-923.
  • PURPOSE: To compare diagnostic performance for prediction of malignant potential in IPMNs between EUS, contrast-enhanced CT and MRI.

    CONCLUSION: Diagnostic performance of contrast-enhanced CT, MRI, and EUS for predicting malignant IPMNs was comparable with each modalities without significant difference.

    
Diagnostic performance and imaging features for predicting the malignant potential of intraductal papillary mucinous neoplasm of the pancreas: a comparison of EUS, contrast-enhanced CT and MRI.
Choi SY et al.
Abdom Radiol  2017 Jan 31. doi: 10.1007/s00261-017-1053-3. [Epub ahead of print]

  • RESULTS: Diagnostic performance of contrast-enhanced CT (AUC = 0.792 in R1, 0.830 in R2), MRI (AUC = 0.742 in R1, 0.776 in R2), and EUS (AUC = 0.733) for predicting malignant IPMNs were comparable without significant difference (p > 0.05). In multivariable analysis, enhancing solid component in contrast-enhanced CT and MRI and mural nodule in EUS (OR 1.8 in CT, 1.36 in MRI, 1.47 in EUS), MPD diameter ≥ 10 mm (OR 1.3 in CT, 1.4 in MRI, 1.66 in EUS), MPD diameter of 5-9 mm (OR 1.23 in CT, 1.31 in MRI), and thickened septa or wall (OR 1.3 in CT and MRI) were significant variables (p < 0.05). Interobserver agreement of thickened cyst septa or wall (k = 0.579-0.617) and abrupt caliber change of MPD (k = 0.689-0.788) was lower than other variables (k > 0.80).


    Diagnostic performance and imaging features for predicting the malignant potential of intraductal papillary mucinous neoplasm of the pancreas: a comparison of EUS, contrast-enhanced CT and MRI.
Choi SY et al.
Abdom Radiol  2017 Jan 31. doi: 10.1007/s00261-017-1053-3. [Epub ahead of print]

  •  “The pancreas is an unusual site of secondary tumors. Melanoma, lung cancer and breast carcinoma are the most common origins of multiple pancreatic metastases, whereas renal cell carcinoma usually leads to a single pancreatic metastasis. The interval between the diagnosis of the primary tumor and the development of pancreatic metastases varies between 1 and 3years, except for renal cell carcinoma for which pancreatic metastases may appear after more than 20 years.”

    
Imaging features of rare pancreatic tumors 
M. Barrala, S.A. Faraound, E.K. Fishman, A. Dohan, C. Pozzesserea, M.-A. Berthelina,P. Bazeries, M. Barat, C. Hoeffel, P. Soyer 
Diagnostic and Interventional Imaging (2016) (in press)
  • Management of Cystic Pancreatic Lesions
  • Impact of MPCC
  • Impact of MPCC
  • “In conclusion, multidisciplinary input associated with a MPCC is helpful in the management of patients with pancreatic cysts and alters the management of up to 30 % of patients assessed.”
    Role of a Multidisciplinary Clinic in the Management of Patients with Pancreatic Cysts: A Single-Center Cohort Study
    Lennon AM, Manos LL, Hruban RH, Ali SY, Fishman EK et al.
    Ann Surg Oncol DOI 10.1245/s10434-014-3739
  • “The most common diagnosis was branch duct intraductal papillary mucinous neoplasm. MPCC review altered the risk category in 11 (8.0%) of 138 patients. The management category was altered in 68 (30.2%) of 225 patients. Management was increased in 52 patients, including 22 patients who were recommended surgical resection. Management was decreased in 16 patients, including 10 who had their recommendation changed from surgery to surveillance.”
    Role of a Multidisciplinary Clinic in the Management of Patients with Pancreatic Cysts: A Single-Center Cohort Study
    Lennon AM, Manos LL, Hruban RH, Ali SY, Fishman EK et al.
    Ann Surg Oncol DOI 10.1245/s10434-014-3739
  • “The MPCC altered the management of a third of patients assessed in the clinic. In the majority of cases, surveillance was recommended, with surgery recom- mended in just under 10 % of all patients, although no further follow-up was required in just under 2 % of patients who had benign disease. None of the patients in whom the recommendation was changed from surgery to surveillance developed evidence of malignancy during follow-up.”
    Role of a Multidisciplinary Clinic in the Management of Patients with Pancreatic Cysts: A Single-Center Cohort Study
    Lennon AM, Manos LL, Hruban RH, Ali SY, Fishman EK et al.
    Ann Surg Oncol DOI 10.1245/s10434-014-3739
  •  “The Whipple procedure is associated with a set of common complications, including pancreatic fistula, postsurgical hemorrhage, postoperative pancreatitis, portomesenteric venous thrombosis, hepatic infarction, delayed gastric emptying, and anastomotic strictures.”
    CT after pancreaticoduodenectomy: spectrum of normal findings and complications.
    Raman SP, Horton KM, Cameron JL Fishman EK.
    AJR Am J Roentgenol. 2013 Jul;201(1):2-13.
  • “ CT might be useful for preoperatively evaluating the T category, lymph node metastasis, tumor size, and perineural invasion of IPMC. Main pancreatic duct dilatation and the presence of mural nodules are common findings of IPMC.”
    Intraductal Papillary Mucinous Neoplasms With Associated Invasive Carcinoma of the Pancreas: Imaging Findings and Diagnostic Performance of MDCT for Prediction of Prognostic Factors
    Kim JH et al.
    AJR 2013; 201:565-572
  • “ Tumor size is also reported to be a prognostic factor in IPMN. Some studies have suggested that tumor diameter of more than 3 cm is associated with an increased risk of malignancy. In our study, MDCT accurately measured the tumor size but was not statistically different from that of the surgical specimen.”
    Intraductal Papillary Mucinous Neoplasms With Associated Invasive Carcinoma of the Pancreas: Imaging Findings and Diagnostic Performance of MDCT for Prediction of Prognostic Factors
    Kim JH et al.
    AJR 2013; 201:565-572
  • "Prediction of the pathologic subtypes of pancreatic IPMNs by CT is limited. Predominant main pancreatic duct involvement and a wide connection of a side branch lesion with the main pancreatic duct are the only CT findings that can be used to predict the pathologic subtype of pancreatic IPMN (carcinoma)."

    Pancreatic Intraductal Papillary Neoplasms: Role of CT in Predicting Pathologic Subtypes
    Gupta R et al.
    AJR 2008; 191;1458-1464

  • IPMN: Histologic Characterization
    - Adenoma
    - Borderline malignancy
    - Moderate dysplasia
    - Carcinoma in situ
    - Invasive carcinoma
    - Progression may take 5 years or more
  • "A diameter of the main pancreatic duct (MPD) of 6.0 mm or more, an abnormal attenuating area in the surrounding parenchyma,and a mural nodule in the MPD or in any associated cystic lesion of 3 mm or larger support the diagnosis of malignancy of the intraductal papillary neoplasm."

    Intraductal Papillary Mucinous Neoplasm of the Pancreas: Assessment of the Likelihood of Invasiveness with Multisection CT
    Ogawa H et al.
    Radiology 2008; 248:876-886

  • "Multiphase contrast enhanced CT with a multisection CT scanner is helpful for distinguishing among adenoma, noninvasive carcinoma, and invasive carcinoma in patients with IPMN and such a distinction provides valuable information to assist the clinician in guiding patient treatment."

    Intraductal Papillary Mucinous Neoplasm of the Pancreas: Assessment of the Likelihood of Invasiveness with Multisection CT
    Ogawa H et al.
    Radiology 2008; 248:876-886

  • "Multisection CT is useful for distinguishing among adenoma, noninvasive carcinoma and invasive carcinoma in patients with IPMN."

    Intraductal Papillary Mucinous Neoplasm of the Pancreas: Assessment of the Likelihood of Invasiveness with Multisection CT
    Ogawa H et al.
    Radiology 2008; 248:876-886

  • "Computed tomography findings suspicious for tumor recurrence include enlarging mass (either solid,cystic or both), progressive duct dilatation, or extrapancreatic disease."

    Recurrence Patterns of Intraductal Papillary Mucinous Neoplasms of the Pancreas on Enhanced Computed Tomography
    Landa J et al.
    J Comput Assist Tomogr 2009;33: 838-843

  • IPMN: Patterns of Recurrence
    - Enlarging mass at resection site
    - New mass developing in remaining gland
    - Progressive duct dilatation
    - Extrapancreatic disease
  • "Allen and Brennan proposed that selected patients with mucinous cysts without a solid component and of less than 3-cm diameter can be safely followed because the risk of malignancy approximates the risk of mortality from surgical resection."

    Prevalence of Unsuspected Pancreatic Cysts on MDCT
    Laffan TA, Horton KM, Fishman EK, Hruban RH
    AJR 2008;802-807
  • "CT falls short of MRCP in detecting a ductal connection, estimating main duct involvement, and identification of small branch duct cysts. These factors influence diagnostic accuracy, cancer risk stratification and operative strategy."

    CT vs MRCP:Optimal Classification of IPMN type and Extent
    Waters JA et al.
    J Gastrointest Surg (2008) 12:101-109
  • "Of 214 patients treated with IPMN(1991-2006), 30 had preoperative CT and MRCP. Of these, 18 met imaging study criteria."

    CT vs MRCP:Optimal Classification of IPMN type and Extent
    Waters JA et al.
    J Gastrointest Surg (2008) 12:101-109
    comment: only axial CT used and to study duct CPR and 3D are ideal. Also study over many types of CT
  • "CT is helpful in the differentiation of in situ and invasive IPMN. Classic vascular invasion criteria lead to the overestimation of surgical tumor unresectability in patients with malignant IPMN."

    Malignant Intraductal Papillary Mucinous Neoplasm of the Pancreas: In Situ versus Invasive Carcinoma-Surgical Resectability
    Vullierme MP et al.
    Radiology 2007;245:483-490
  • "Radiographic features that correlated with malignancy were presence of a solid component, main pancreatic duct dilatation, common bile duct diltation, and lymphadenopathy. Twenty seven of 31 (87%) patients with malignant lesions had at least one radiographic feature concerning for malignancy."

    Risk of Malignancy in Resected Cystic Tumors of the Pancreas =3cm in Size:Is it Safe to Observe Asymptomatic Patients? A Multi-Institutional Report
    Lee CJ et al.
    J Gastrointest Surg (2008) 12:234-242
  • "Based on retrospective analysis, this multi-institutional review of resection data of small cystic lesions from high volume centers suggests that a group of patients with a low risk of malignancy can be identified and be safely followed in accordance with the current consensus guidelines."

    Risk of Malignancy in Resected Cystic Tumors of the Pancreas =3cm in Size:Is it Safe to Observe Asymptomatic Patients? A Multi-Institutional Report
    Lee CJ et al.
    J Gastrointest Surg (2008) 12:234-242
  • "Pancreas protocol CT imaging appears to be a better predictor of resectability compared with EUS. EUS accuracy is affected by the presence of biliary stents."

    Endoscopic Ultrasound and Computed Tomography Predictors of Pancreatic Cancer Resectability
    Bao PQ et al
    J Gastrointest Surg (2008) 12:10-16
  • Cystic Pancreatic Tumors: Features For Low Risk of Malignancy

    - Asymptomatic patient
    - Size under 3 cm
    - Main pancreatic duct under 6 mm
    - No solid component (mural nodule) within or associated with the cystic lesion
    - No evidence of adenopathy
    - No common bile duct dilatation
  • "Radiographic features that correlated with malignancy were presence of a solid component, main pancreatic duct dilatation, common bile duct diltation, and lymphadenopathy. Twenty seven of 31 (87%) patients with malignant lesions had at least one radiographic feature concerning for malignancy."

    Risk of Malignancy in Resected Cystic Tumors of the Pancreas =3cm in Size:Is it Safe to Observe Asymptomatic Patients? A Multi-Institutional Report
    Lee CJ et al.
    J Gastrointest Surg (2008) 12:234-242
  • "Based on retrospective analysis, this multi-institutional review of resection data of small cystic lesions from high volume centers suggests that a group of patients with a low risk of malignancy can be identified and be safely followed in accordance with the current consensus guidelines."

    Risk of Malignancy in Resected Cystic Tumors of the Pancreas =3cm in Size:Is it Safe to Observe Asymptomatic Patients? A Multi-Institutional Report
    Lee CJ et al.
    J Gastrointest Surg (2008) 12:234-242
  • "Our results suggest that by combining data from both CT and EUS, a clinically relevant scoring system can be utilized to help select appropriate interventions and therapy for patients with pancreatic cancer."

    Predicting Unresectability in Pancreatic Cancer Patients: The Additive Effects of CT and Endoscopic Ultrasound
    Yovino S et al.
    J Gastrointest Surg (2007) 11:36-42
  • "Arterial dominant phase CT is useful for detecting invasive carcinoma derived from IPMNs and is an effective followup method."

    Invasive Carcinomas Derived From Intraductal Papillary Mucinous Neoplasms of the Pancreas: A Long term Follow-up Assessment with CT Imaging
    Yamada Y et al.
    J Comput Assist Tomogr 2006;30:885-890
  • IPMN

    - 1. IPMN Adenoma
    - 2. IPMN Borderline
    - 3. IPMN Carcinoma in situ
    - 4. IPMN Invasive carcinoma
    - A. Colloid Carcinoma-Muc 2
    - B. Ductal Carcinoma- Muc 1
  • Intraductal Papillary Mucinous Neoplasm

    - 1.Proliferation of mucinous epithelial cells lining pancreatic ducts- arranged in papillary patterns.
    - 2. Intraluminal accumulation of mucin and cystic dilatation of ducts.
    - 3. Spectrum of architectural atypia from benign to malignant.
  • IPMN

    - 4. 1/3 of cases associated with invasive carcinoma.
    - 5. Communicate with pancreatic duct, ( unlike MCN ).
    - 6. No ovarian stroma.
    - 7. Mucin may be seen pouring into duodenum from patulous orifice of pancreatic duct.
  • - 1.Proliferation of mucinous epithelial cells lining pancreatic ducts- arranged in papillary patterns.
    - 2. Intraluminal accumulation of mucin and cystic dilatation of ducts.
    - 3. Spectrum of architectural atypia from benign to malignant.
  • Guidelines

    - 1. Asymptomatic cystic lesions without main duct dilatation [> 6 mm], those without mural nodules, and those < 30 mm in size have a low risk of progressing to invasive cancer in near-term [ 12 –to 36 month] followup.
    - 2. Yearly followup if lesion is <10 mm in size. 6-12 month follow-up for lesions 10-20 mm. 3-6 month followup for lesions >20 mm.
    - 3. Interval can be lengthened after 2 yrs of no change
    - 4. Appearance of sx attributable to the cyst [eg pancreatitis], presence of intramural nodules, cyst size > 30 mm, or dilatation of pancreatic duct >6mm are indications for resection.
  • Question #3 - Are there any endorsed criteria for conservative follow-up of a cystic pancreatic lesion?

    - Tanaka M et al. International Consensus Guidelines for Management of Intraductal Papillary Mucinous Neoplasms and Mucinous Cystic Neoplasms of the Pancreas. Pancreatology 2006; 6:17-32.
    - Consensus of the Working Group of the International Association of Pancreatology.
  • Conclusions from recent studies

    - Commonest small cysts are MCN, IPMN, and serous.
    - Very few pseudocysts in absense of pancreatitis.
    - Fewer than 5% of incidentally detected pancreatic cysts <2cm are malignant.
    - Patient’s choice: Follow, Bx under US, surgery.
    - General consensus:
    - 1. Under 2 cm observe.
    - 2. >2cm Young and middle-aged resect.
    - 3. >2cm older and less fit. Endoscopic US with fine needle aspiration, [ 40-50% sensitivity, 99+% specificity ]. Resect if mucin, high CEA, mucinous epithelium, malignant cells, or neuroendocrine cells.
  • The natural history of the incidentally discovered small simple pancreatic cyst; long term follow-up and clinical implications

    - Handrich SJ et al. AJR 2005; 184: 20-23. Mayo Clinic.
    - <2.0 cm cysts dx by sonography or CT 1985-1996.
    - 79 pts. 49 adequate follow-up.
    - 13 [ 59% ] no change or smaller. Mean size 8 mm, mean follow-up 9 years.
    - 9 [ 415 ] enlarged. Mean 14 mm to 26 mm. Mean follow-up 8 years. One pt operated on- pseudocyst.
    - 27 clinical follow-up or response to questionaire. Mean follow-up 10 years. None developed pancreatic disease.
    - 18 patients died. No suggestion of pancreatic disease.
    - 12 patients lost to follow-up.
  • Pancreatic cysts 3 cm or smaller: How aggressive should treatment be?

    - Sahani DV et al Radiology 2006; 238: 912-919. Mass General
    - 510 pts with cysts 1998-2004. 122 pancreatitis excld. 313/388 {80.6%} <3cm.
    - 86 patients in study with adequate data. Aged 24-89 years.
    - 48 surgery vs 38 non surgical.
    - 75 benign, 8 borderline malignant, 3 ca in situ.
    - Results of surgery: 37 benign MCN 13, IPMN side branch 14, serous 3, pseudocyst, cystic neuroendocrine 2, lymphoepithelial cyst 1, unclass 2 11 malignant
    - 8 borderline : 6 side-branch, 2 MCN. 3 ca in situ: 2 side-branch, 1 MCN.
    - 38 pts followed, all had US bx -1 later developed side-branch IMN with ca in situ.
  • Cystic pancreatic neoplasms- Observe or operate?

    - Spinnelli KS et al. Annals of Surgery 2004; 239: 651-659. U.Wisconsin. 1995-2002.
    - 290 cysts 1.2%. 132 hx pancreatitis thus, 168, 0.7% incidence of presumed neoplastic cysts.
    - 79 patients followed -16 months mean.
    - 15 increased in size [ 19% ]
    - 47 no change in size [ 59% ]
    - 17 decrease in size [ 22% ]
    - 49 had surgery
    - 14 benign 10 serous, 2 SPEN, 1 lymphoep, 1 simple cyst
    - 25 premalignant 16 MCN, 5 IPMn, 4 cystic neuroendocrine
    - 10 malignant 7 IPMN with Ca, 3 MCN
    - Recommend surgery if symptomatic, increasing, or fit older pts, since 60% of cysts in pts over 60 were malignant.
  • "Pathologic analysis revealed carcinoma in situ in seven patients (19%) and invasive carcinoma in 15 patients (42%) arising from the IPMN. With invasive carcinoma, the size of the tumor in branch duct type and combined type, and the caliber of the main pancreatic duct were significantly larger compared with the lesions without invasive carcinoma (4.7 +/- 1.7 cm vs 2.6 +/- 1.4 cm [p = 0.0007] and 9.3 +/- 5.5 mm vs 4.6 +/- 4.1 mm [p = 0.006], respectively)."

    MDCT of intraductal papillary mucinous neoplasm of the pancreas: evaluation of features predictive of invasive carcinoma
    Kawamoto S et al.
    AJR 2006 March;186(3):687-695.
  • "The use of high resolution axial, multiplanar reformatted, and three dimensional reformatted images as demonstrated by Kawamoto et al using 16 slice MDCT improves diagnostic performance and enables depiction of the connection between the cystic lesions of IPMN and the pancreatic duct."

    Stoupis C (commentary)
    RadioGraphics 2005; 25:1468-1470
  • Intraductal Papillary Mucinous Neoplasms of the Pancreas

    - Dilated main pancreatic duct
    - Diffuse or multifocal involvement
    - Presence of a large mural nodule or a solid mass
    - Large size of the mass
    - Obstruction of the common bile duct
  • Intraductal Papillary Mucinous Tumor (IPMN): Facts

    - Equal frequency men and woman
    - Usually detected in 6th and 7th decade
    - Commonly associated with dilated pancreatic duct
    - Lesions may be multiple and variable in size
  • Intraductal Papillary Mucinous Tumor (IPMN): Facts

    - Initially referred to as mucin producing pancreatic neoplasms
    - May be incidental finding or patients present with pancreatitis like symptoms
    - Up to 60% occur in the head/uncinate process
  • Cystic Endocrine Tumors

    - Insulinomas
    - Gastrinomas
    - Glucagonomas
    - Non-functioning tumors
  • IPMN: facts

    - Main or side branch duct dilatation common
    - Most common in uncinate
    - Can be multiple throughout the pancreatic gland
  • "The use of high resolution axial, multiplanar reformatted, and three dimensional reformatted images as demonstrated by Kawamoto et al using 16 slice MDCT improves diagnostic performance and enables depiction of the connection between the cystic lesions of IPMN and the pancreatic duct."

    Stoupis C (commentary)
    RadioGraphics 2005; 25:1468-1470
  • Intraductal Papillary Mucinous Neoplasms of the Pancreas

    - Dilated main pancreatic duct
    - Diffuse or multifocal involvement
    - Presence of a large mural nodule or a solid mass
    - Large size of the mass
    - Obstruction of the common bile duct
  • "Preoperative multidetector CT can help predict the presence of invasive carcinoma associated with IPMN."

    Intraductal Papillary Mucinous Neoplasm of the Pancreas: Can Benign Lesions Be Differentiated from Malignant Lesions with MDCT?
    Kawamoto S, Horton KM, Lawler LP, Hruban RH, Fishman EK
    RadioGraphics 2005; 25:1451-1470
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