Subepithelial Lesions of the Gut: When Should I Worry?

Transcription

1 Subepithelial Lesions of the Gut: When Should I Worry? President, ASGE Chairman, GI & Hepatology Scottsdale, AZ Faigel.douglas@mayo.edu Case 55 yo male with reflux EGD for Barrett s Screening SET, mucosal biopsies negative DDx? Evaluation? Prognosis Page 1 of 21

2 First step: EUS Pentax Olympus Page 2 of 21

3 Differential Diagnosis Wall layer of origin 3rd layer (Submucosa) 4th layer (muscularis propria) Extrinsic Echofeatures Echogenicity (brightness) E.g. bright=lipoma, anechoic=cyst Shape E.g. serpiginous = vessels (varices) Page 3 of 21

4 Subepithelial Lesions Submucosa Muscularis Extrinsic Carcinoid Lymphoma GIST Metastasis Lipoma Granular cell Pancreas rest Inflammatory Cyst Varices GIST (CD117) Leiomyoma (SMA) Neuroma (S100) Lymphoma Endometriosis Metastasis Liver Spleen (acc) Gallbladder Splenic Art. Pseudocyst Renal cysts Extrinisic Tumor = worry about Gastric SMT: Lipoma Page 4 of 21

5 Gastric SMT: GIST Leiomyoma Page 5 of 21

6 Spindle Cell Tumors Spindle cell morphology 4th layer (typically) GIST (CD117, CD34, DOG1) Leiomyoma (SMA, Desmin) Neuroma (S100) GIST Is Thought to Arise From Interstitial Cells of Cajal Interstitial cells of Cajal1 Pacemaker cells associated with Auerbach s plexus Likely cellular progenitor CD117 (c-kit) expression, structural similarities1,2 Cells of Cajal GIST 1. Rubin BP et al. Lancet. 2007;369: Kindblom L-G et al. Am J Pathol. 1998;152: Page 6 of 21

7 GIST Mesenchymal tumor C-kit proto-oncogene Tyrosine kinase Metastatic potential >4 cm, >5 mitoses/50 hpf Surgery indicated Especially >2 cm, non-gastric Gleevec for metastatic disease Neodjuvant trials CD117 (KIT) staining GIST Epidemiology Classified as a sarcoma Variable aggressiveness Incidence: 15-20/million Approx 6000 new cases in US per year Locations: Stomach (40-70%) Small intestine (20-50%) Colon (5-15%) Esophagus (2%) CT: Calcified Duodenal GIST Page 7 of 21

8 Presentation Depends on location and size Symptoms: GI Bleeding (20-50%) Abdominal pain (40-50%) Palpable mass (25-40%) Incidentally found (10-30%) Wide age range 75% patients >50 yrs Median age: 58 yrs No gender predilection Malignancy Sarcoma with variable aggressiveness Malignant behavior in at least 30% Defined as GIST Liver Mets Omental, mesenteric, peritoneal seeding Invasion adjacent organs Metastasis Recurrence post-resection Metastatic Sites: Liver (50%) Lung (10%) Bone (<10%) Note: lymph nodal metastasis RARE Page 8 of 21

9 GIST: Risk for Malignancy Size1 Location1 Small bowel worse than Features associated with malignancy on EUS (P<0.05)3,4 Size >4 cm gastric Irregular margin* Mitotic index1 Echogenic foci* Requires a resected Cystic spaces* tumor *If 2 of 3 present, Average of 50 HPF SENSITIVITY for (high-powered fields) malignancy = 80% Mutational status2 100%. Exon 9, 11, 13 *If none present, mutations confer poorer SPECIFICITY for prognosis benignity = 89%1. Miettinen M et al. J. Arch Pathol Lab Med. 2006;130: % 2. Davila RE et al. Gastrointest Endosc. 2003;58: Palazzo L et al. Gut. 2000;46: Chak A et al. Gastrointest Endosc. 1997;45: CD-117 positive vs. CD-117 negative Spindle Cell Tumors: EUS Features CD-117+ >4 cm 6/17* Ulcer 7/17 Cysts 3/17 Any 11/17** CD-117-1/12 0/12 0/12 1/12 *average size (CD-117+ vs. CD-117-) 4.2 vs. 1.9 cm, p=0.006 **p=0.006 Esophageal location (CD-117+ vs. CD-117-) 2/17 vs. 9/12, p<0.01 Hunt G, Faigel DO GIE Page 9 of 21

10 Overall Survival Following Surgery 1.0 Survival following surgical treatment of primary GIST (N = 80) Disease-specific survival rate at 5 years post-resection was 54% 0.8 Fraction 0.6 Surviving Years in 2 patients with GIST recur following resection Plaat et al. J Clin Oncol. 2000;18: yr vs. 1-yr Year Adjuvant Imatinib: Recurrence-Free Survival High risk GIST Joensuu H et al JAMA 2012 Page 10 of 21

11 Surveillance Candidates: Asymptomatic, gastric, <2 cm No worrisome EUS features EUS-based Number and timing unknown Yearly? Resect tumors that enlarge Small studies show little change in size over 1-2 years 13% enlarged Routine post-operative: not indicated Faigel DO J Clin Gastro 2012; Lok KH J Gastro Liv Dis 2009; Gill KRS J Clin Gastro 2009 Colonic SMT 45 yo female Rectal Bleeding Endometriosis Page 11 of 21

12 Tissue Diagnosis Do you need tissue? How badly do you want a diagnosis? Special equipment, costs, risks Forceps biopsy Frequently non-diagnostic Ulcerated lesions Carcinoids Approach determined by wall layer of origin Carcinoid Tissue: 3rd Layer Well technique Jumbo forceps, bite-on-bite Yield: 17% (prospect) to 39% (retrosp) Endoscopic mucosal-submucosal resection (ESMR) Cap EMR, no saline Band ligation Page 12 of 21

13 ESMR Yield 87% (n=23) P= vs well technique (17%) Bleed 13-16% immediate EMR: 0-24% bleed Cantor MJ et al. Gastrointest Endosc. 2006;64:29-34 ESMR Page 13 of 21

14 ESMR Complication Tissue: 4th Layer EUS-FNA Cytology needles (19-25g) Biopsy needles Histology? Mitotic index? Increase yield? Immunohistochemistry SENS for GIST: 78%* Endoscopic resection described** ESMR, ESD, band/loop ligation, NOTES, tunnel Risk for incomplete resection, perforation Endoscopic incision/unroofing and biopsy *Sepe PS et al. Gastrointest Endosc. 2009;70: **Faigel DO, J Clin Gastro 2012 Page 14 of 21

15 GIST Majority of FNA Samples Are Diagnostic Results of Suspected GISTS (N=112)1 Histology Findings1 Nondiagnostic 16% Nondiagnostic 16% Suspicious 22% Neural 4% GIST 31% Diagnostic 62% Spindle Cell 22% Leiomyoma 27% FNA, fine needle aspiration Hoda KM et al. Gastrointest Endosc. 2009;69: Page 15 of 21

16 GIST: Biopsy Needle Gastric Subepithelial Tumor Page 16 of 21

17 Neuroendocrine Tumors (Carcinoids) Tumors amenable to EUS evaluation and endoscopic treatment* Rectum (70%)* Stomach (20%) Type 1 (atrophic gastritis)* Duodenum (10%) Non-syndromic* Rectal Carcinoid NET: Role of EUS Diagnosis If prior biopsy non-dx Dark round lesion 2nd-3rd layers Measuring Size Remember <1 cm good Depth of invasion 90% accurate Remember MP bad Detecting lymph nodes EUS-FNA Selection for EMR Yoshikane H GIE 1993 Page 17 of 21

18 Endoscopic Mucosal Resection Patient Selection Size <1-2 cm No poorly differentiated histology No MP invasion No adenopathy Gastric Type 1: 5 macroscopic tumors (>5 mm) Gastric Carcinoid Duodenal Carcinoid Page 18 of 21

19 NET: Follow-up After EMR Endoscopy at 6 months intervals Duodenum and rectum 2-3 years Gastric (Type 1) 2-3 yrs then yearly thereafter Role of EUS Lesions >1 cm Microscopically positive margins Re-resect if residual tumor identified vs. surgery (rarely needed) Consider Octreoscan and Chromogranin A Octreoscan RARELY positive Chr A positive in atrophic gastritis Gangliocytic Paraganglioma Rare tumor papilla NET-like NOT a carcinoid Benign May be symptomatic: Bleed, pancreatitis, CBD obstruction Amenable to endoscopic resection (ERCP) Surgery if large Morita T Dig Dis Sci 2007 Rafiullah BMJ Case Report Page 19 of 21

20 SET: When to Worry? Worry about: GIST Carcinoids Symptomatic tumors Require resection Endoscopic vs. surgical SET 4th layer 3rd layer Tissue needed? ESMR: 87% yield 16% bleed FNA/B: 60-80% yield CD117 + GIST Diagnosis CD117SMA+ or S100+ Non-GIST Resect vs. close f/u leiomyoma neuroma Observe Page 20 of 21

21 Thank you!! Page 21 of 21