Esophagus: Diagnosis and Margins



Esophagus: Diagnosis and Margins










The most common esophageal tumor is adenocarcinoma image arising near the gastroesophageal (GE) junction. The proximal margin is image is covered by squamous mucosa and the distal margin is in the stomach image.






Esophageal carcinomas are treated with neoadjuvant chemotherapy. Tumors that respond well may only show an ulcer or scar image and can be very difficult to identify grossly and microscopically.


SURGICAL/CLINICAL CONSIDERATIONS


Goal of Consultation



  • Determine whether proximal and distal margins are free of carcinoma and dysplasia


Change in Patient Management



  • Additional tissue at proximal or distal margin may be resected


Clinical Setting



  • Neoplasms of esophagus are frequently detected due to clinical symptoms



    • Surgery may be indicated for potential cure or palliation


  • Majority of lesions will have been diagnosed by endoscopic biopsy


  • Many carcinomas undergo preoperative chemotherapy or radiation therapy


  • Status of margins can be difficult to evaluate by frozen section for some lesions



    • Adenocarcinomas associated with Barrett mucosa and dysplasia


    • Diffusely invasive signet ring cell carcinomas of stomach


    • Carcinomas after treatment


SPECIMEN EVALUATION


Gross



  • Identify esophagus, stomach, and duodenum (if present in complete gastrectomy)


  • Examine outer surface for tumor involvement


  • Ink serosa and adventitia along area to be opened



    • For partial gastrectomies, margin can be marked with clips to aid in identification after opening


  • Open along greater curvature of stomach unless lesion is located at this site



    • Open stapled margins as close to staples as possible


  • Identify cancer site



    • Cancers above gastroesophageal (GE) junction are usually squamous cell carcinomas


    • Cancers at GE junction are usually adenocarcinomas



      • Often associated with Barrett mucosa; pink granular appearance


    • Cancers in stomach are usually adenocarcinomas



      • Majority present with ulcerated center and heapedup edges


      • Signet ring cell carcinomas may present as linitis plastica; muscularis propria is diffusely thickened; mucosal surface may appear normal


  • If there has been prior treatment, cancer site may be subtle area of ulceration or fibrosis


  • Measure distance of cancer or tumor bed to closest proximal and distal margins



    • GE junction adenocarcinomas can invade under overlying normal squamous mucosa for 1-2 cm


    • Signet ring cell carcinomas can invade below overlying normal mucosa and in muscularis of stomach for several cm


Frozen Section



  • Section of closest margin to cancer is selected


  • Margin section must include full cross section of mucosa, submucosa, and muscularis propria



    • Mucosa can sometimes curl over at cut edge of specimen due to retraction of muscularis propria


    • It may be necessary to retract mucosa slightly to get a full-thickness section


  • Distal (gastric) margin is usually far from carcinoma



    • Representative section can be frozen but is rarely positive


    • In cases of signet ring cell carcinoma or other primary gastric carcinomas, more extensive evaluation of margin may be indicated


  • Margins can be taken en face (parallel to margin) or perpendicular to margin


MOST COMMON DIAGNOSES


Barrett Mucosa



  • Replacement of normal squamous mucosa of distal esophagus by abnormal glandular mucosa



  • May be patchy and discontinuous


  • Recognized by pale pink, finely granular tissue replacing normal white, smooth, and glistening squamous surface


  • Areas of high-grade dysplasia and small carcinomas may form small areas of heaped-up mucosa


  • Esophageal margin should be free of Barrett mucosa


Adenocarcinoma, Intestinal Type



  • Usually arise in distal esophagus in area of Barrett mucosa



    • Can be multifocal


  • Tan-pink masses with heaped-up borders and central ulceration are typical


Adenocarcinoma, Signet Ring Cell Type



  • Signet ring cell carcinomas are more common in stomach


  • Diffuse involvement of mucosa and muscularis can be difficult to detect grossly and on frozen section



    • Muscularis propria may be diffusely thickened (linitis plastica)


  • Signet ring cells can be difficult to distinguish from histiocytes or plasma cells


Squamous Cell Carcinoma



  • Arise at any level of esophagus



    • Can be multifocal


  • May be exophytic, ulcerating, or cause diffuse thickening and narrowing of lumen


  • Many will have been treated with preoperative radiation therapy



    • After treatment, tumor bed may be a subtle area of shallow ulceration or granular-appearing squamous mucosa


    • Radiation atypia may be difficult to distinguish from carcinoma in situ


  • Esophageal margin should be evaluated for squamous cell carcinoma in situ as well as for invasive carcinoma


Leiomyoma or Gastrointestinal Stromal Tumor (GIST)



  • Arise from muscularis


  • Well-circumscribed, pink to white masses with whorled appearance


  • Spindle cells grow in fascicles


  • GIST is rare in this location



    • Majority are malignant


  • Margins can be evaluated grossly


Granular Cell Tumor



  • Arise in submucosa or muscularis propria of distal esophagus


  • Abundant granular pink cytoplasm


  • Overlying mucosa is intact



    • Pseudoepitheliomatous hyperplasia can mimic squamous cell carcinoma


REPORTING


Frozen Section



  • Margins positive or negative for invasive carcinoma, carcinoma in situ, Barrett mucosa, or tumor bed


  • If carcinoma is close to margin, distance from margin is reported


PITFALLS


Carcinoma vs. Treatment-Related Changes

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Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Esophagus: Diagnosis and Margins

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