4 April 2013 - Case #270
All cases are archived on our website. To view them sorted by case number, diagnosis or category, visit our main Case of the Month page. To subscribe or unsubscribe to Case of the Month or our other email lists, click here.
Thanks to Dr. Saroona Haroon, The Aga Khan University Hospital (Pakistan), for contributing this case.
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Case #270
Clinical history:
A 65 year old man presented with multiple intestinal and mesenteric nodules. A nodule was excised and submitted in multiple pieces.
Microscopic images:
What is your diagnosis?
Diagnosis: Epthelioid gastrointestinal stromal tumor, plasmacytoid variant
Immunostains:
Discussion:
Gastrointestinal stromal tumors (GISTs) differentiate along lines of the interstitial cell of Cajal, the guts pacemaker cell. Behavior varies by site. In the small bowel, 30 - 50% of tumors have malignant behavior. The median patient age for small bowel GIST is 67 years and patients often present with large, bulky masses that may be well circumscribed. Most (70%) tumors have the classic spindle cell pattern but 20% are epithelioid and 10% are mixed. Epithelioid tumor cells are usually malignant appearing, with abundant eosinophilic cytoplasm.
GIST tumors are typically CD117+, CD34+ and vimentin+, as in this case. The uncommon CD117- GIST tumors may be positive for DOG1 or PKC8 (Mod Pathol 2011;24:866, Clin Med Insights Pathol 2012;5:23)
Plasmacytoid features in epithelioid GIST have been described in cytology specimens and in patients with features suggestive of Carney's triad (Pediatr Infect Dis J 2024;43:400, Acta Cytol 2005;49:435, Diagn Pathol 2011;6:52). The plasmacytoid cells which were CD38+ (a plasma cell marker), may have actually been plasma cells.
The differential diagnosis includes inflammatory fibroid polyp (spindle and stellate cells with onion skinning around blood vessels, eosinophils, lymphocytes and plasma cells; CD34+ spindle cells are KIT-, DOG1-) and lymphoid / plasma cell neoplasms (no areas resembling GIST, positive for B cell markers, CD34-, CD117-).
Tyrosine kinase inhibitor therapy, including Gleevec (STI571) is usually effective treatment for GIST tumors (NIH: Gastrointestinal Stromal Tumors Treatment [Accessed 5 April 2024]). Surgery is also an option in many cases. Historically the 5 year overall survival of small bowel GIST was only 50%, although recent reports show marked improvement (BMC Gastroenterol 2006;6:29, J Gastric Cancer 2012;12:243).
All cases are archived on our website. To view them sorted by case number, diagnosis or category, visit our main Case of the Month page. To subscribe or unsubscribe to Case of the Month or our other email lists, click here.
Thanks to Dr. Saroona Haroon, The Aga Khan University Hospital (Pakistan), for contributing this case.
May 4, 2013
The Dearborn Inn
Dearborn, MI
Michigan Society of Pathologists
2013 Spring Conference
Hematopathology
Speakers:
Jeffrey Zonder, MD
Kathryn Foucar, MD
Kristin Hunt-Karner, MD
Website
Hotel
Register
Website news:
(1) In March 2013, we again had record traffic, with 373,735 visits (9,305,497 "hits"). Thanks for your support!
(2) Our Feature Page for April highlights Laboratory Accreditation / Education / CME, and includes ARUP-Scientific Resource for Research and Education and Boardvitals Review for Clinical Pathology. We also have a new Mystery Case on the right side of the Home Page.
(3) We have a new Cytopathology chapter with an Ultrasound-Guided Fine-Needle Aspiration (USFNA) section written by Joe D. Jakowski M.D. and Susan Meanor R.D.M.S., R.T. We have also updated the Leukemia - Acute chapter based on reviews by Daniela Mihova, M.D. and Syed Zaidi, M.D.
(4) Looking for AFIP fascicles (4th series, Tumor or Non tumor)? PathologyOutlines.com is doing some spring cleaning and selling many volumes through Amazon.com, mostly in perfect or near perfect condition. Click here to see what is available.
Visit and follow our Blog to see recent updates to the website.
(1) In March 2013, we again had record traffic, with 373,735 visits (9,305,497 "hits"). Thanks for your support!
(2) Our Feature Page for April highlights Laboratory Accreditation / Education / CME, and includes ARUP-Scientific Resource for Research and Education and Boardvitals Review for Clinical Pathology. We also have a new Mystery Case on the right side of the Home Page.
(3) We have a new Cytopathology chapter with an Ultrasound-Guided Fine-Needle Aspiration (USFNA) section written by Joe D. Jakowski M.D. and Susan Meanor R.D.M.S., R.T. We have also updated the Leukemia - Acute chapter based on reviews by Daniela Mihova, M.D. and Syed Zaidi, M.D.
(4) Looking for AFIP fascicles (4th series, Tumor or Non tumor)? PathologyOutlines.com is doing some spring cleaning and selling many volumes through Amazon.com, mostly in perfect or near perfect condition. Click here to see what is available.
Visit and follow our Blog to see recent updates to the website.
Case #270
Clinical history:
A 65 year old man presented with multiple intestinal and mesenteric nodules. A nodule was excised and submitted in multiple pieces.
Microscopic images:
What is your diagnosis?
Click here for diagnosis and discussion:
Diagnosis: Epthelioid gastrointestinal stromal tumor, plasmacytoid variant
Immunostains:
Left to right: CD34, CD117, CD38
Left to right: AE1 / AE3, S100, vimentin
Discussion:
Gastrointestinal stromal tumors (GISTs) differentiate along lines of the interstitial cell of Cajal, the guts pacemaker cell. Behavior varies by site. In the small bowel, 30 - 50% of tumors have malignant behavior. The median patient age for small bowel GIST is 67 years and patients often present with large, bulky masses that may be well circumscribed. Most (70%) tumors have the classic spindle cell pattern but 20% are epithelioid and 10% are mixed. Epithelioid tumor cells are usually malignant appearing, with abundant eosinophilic cytoplasm.
GIST tumors are typically CD117+, CD34+ and vimentin+, as in this case. The uncommon CD117- GIST tumors may be positive for DOG1 or PKC8 (Mod Pathol 2011;24:866, Clin Med Insights Pathol 2012;5:23)
Plasmacytoid features in epithelioid GIST have been described in cytology specimens and in patients with features suggestive of Carney's triad (Pediatr Infect Dis J 2024;43:400, Acta Cytol 2005;49:435, Diagn Pathol 2011;6:52). The plasmacytoid cells which were CD38+ (a plasma cell marker), may have actually been plasma cells.
The differential diagnosis includes inflammatory fibroid polyp (spindle and stellate cells with onion skinning around blood vessels, eosinophils, lymphocytes and plasma cells; CD34+ spindle cells are KIT-, DOG1-) and lymphoid / plasma cell neoplasms (no areas resembling GIST, positive for B cell markers, CD34-, CD117-).
Tyrosine kinase inhibitor therapy, including Gleevec (STI571) is usually effective treatment for GIST tumors (NIH: Gastrointestinal Stromal Tumors Treatment [Accessed 5 April 2024]). Surgery is also an option in many cases. Historically the 5 year overall survival of small bowel GIST was only 50%, although recent reports show marked improvement (BMC Gastroenterol 2006;6:29, J Gastric Cancer 2012;12:243).
