GIST Specialist for Burbank, CA
Not every mass in the wall of the stomach is a gastrointestinal stromal tumor, and not every GIST is correctly identified as one. The distinction rests on a handful of stains in your pathology report. Joshua Ellenhorn, MD, FACS reads it with you.
- Second reads of existing pathology, no new procedure required
- Clinical Professor of Surgery, Cedars-Sinai Medical Center
- Slides and blocks requested directly from your Burbank hospital
- Twenty five to thirty minutes via the 134 and 101
Several Tumors Grow in the Wall. Only One Is a GIST.
On a CT scan or an endoscopy, a submucosal mass is a submucosal mass. Leiomyomas, schwannomas, inflammatory fibroid polyps, solitary fibrous tumors and GIST all arise inside the wall of the digestive tract and all produce a similar smooth bulge under intact lining.
They require entirely different things. A leiomyoma may need no treatment whatsoever. A GIST needs complete removal with the capsule intact, and possibly three years of imatinib afterwards. Being treated for the wrong one means either an operation you did not need or a cancer managed as though it were benign.
Immunohistochemistry is what separates them, and it is not always fully performed. Where a report describes a spindle cell tumor without CD117 or DOG1 results, the diagnosis is resting on appearance. Where CD117 came back negative and nothing further was done, a real possibility has been left open. Both are worth resolving before anyone operates, and both can be resolved from slides that already exist.
What the Stains on Your Pathology Report Actually Mean
These are the markers a pathologist uses to confirm or exclude GIST. If your report does not mention the first two, that is the first question to ask.
| Marker | What a positive result indicates | Why it matters |
|---|---|---|
| CD117 (KIT) | Positive in roughly 95% of GIST | The classic confirmatory stain. Combined with the right appearance it makes the diagnosis secure |
| DOG1 | Positive in roughly 95%, including many CD117 negative tumors | The stain that rescues the diagnosis when CD117 is negative or equivocal |
| CD34 | Positive in around 70% of GIST | Supportive rather than decisive. Also positive in some other tumors |
| S100 | Suggests schwannoma rather than GIST | A benign nerve sheath tumor requiring very different management |
| Desmin and SMA | Strong positivity suggests a smooth muscle tumor | Points toward leiomyoma, which may need no treatment at all |
| SDHB | Loss of staining indicates SDH-deficient GIST | A distinct subset, often younger patients, can involve lymph nodes, and responds poorly to imatinib |
Alongside these, the report should state the mitotic index. Together with tumor size and site, that is what sets your recurrence risk and decides whether medication is needed after surgery.
What GIST Is, Once Confirmed
GIST arises from the interstitial cells of Cajal, the pacemaker cells within the wall of the digestive tract that coordinate the contractions moving food along. It is a sarcoma, and its behaviour is graded rather than binary: every GIST carries some recurrence risk, set by size, site, and mitotic index.
Because it seldom spreads to lymph nodes, the wide clearance a gastric adenocarcinoma requires is generally unnecessary, and a limited resection can be curative. SDH-deficient tumors are the notable exception, since they can involve nodes, which is one more reason the precise subtype matters.
Nearly all conventional GIST carry a KIT or PDGFRA mutation locking a growth signal on. That is what makes targeted therapy effective, and the subtype determines which drug and what dose. Mutation testing sits alongside the stains above as part of a complete diagnosis rather than an optional extra.
What Follows a Confirmed Diagnosis
Once the tumor is definitely a GIST and the risk is graded, the path becomes clear.
Surveillance or Simple Resection
Small gastric tumors with a low mitotic count may be watched, or removed with a wedge resection and nothing further. No medication, and a surveillance schedule that tapers to an endpoint.
Resection Plus Imatinib
Larger tumors, small bowel origin, or high mitotic counts warrant complete removal followed by roughly three years of adjuvant therapy, with mutation subtype determining whether standard dosing will work.
SDH-Deficient Disease
These behave unlike conventional GIST, respond poorly to imatinib, and can involve lymph nodes. Recognising the subtype changes both the operation and the drug plan, which is why the SDHB stain is worth asking about.
The Operations, Documented
Recordings of real GIST resections narrated by the surgeon who performed them. Relevant once the diagnosis is settled and the question becomes how the tumor comes out.
Laparoscopic Resection of a Gastric GIST
A gastric GIST removed through small incisions with the capsule kept intact.
Gastric GIST Resection: A Simplified Approach
A streamlined approach that shortens operating time and recovery.
Robotic Resection of a Duodenal GIST
Duodenal GIST removed robotically with the pancreas and bile duct preserved.
Existing Slides, No New Procedure
A pathology second read requires nothing from you but the lab name and the accession number. No biopsy, no imaging, no waiting on a new appointment. For an uncertain diagnosis it is the highest value hour available.
Certifications and Appointments
Two American Board of Surgery certifications, a Cedars-Sinai teaching appointment, and membership of the societies that publish the diagnostic guidelines for this disease.
- American Board of Surgery, certified in General Surgery
- American Board of Surgery, certified in Colorectal Surgery
- California State Medical License
- Florida State Medical License
Joshua Ellenhorn, MD, FACS
Dr. Ellenhorn is a surgical oncologist and Clinical Professor of Surgery at Cedars-Sinai Medical Center, and a collaborative member of the Samuel Oschin Comprehensive Cancer Institute.
Practising inside a comprehensive cancer institute matters particularly for the diagnostic question this page is about. Sarcoma pathology is a subspecialty, and the difference between a GIST, a leiomyoma, and an SDH-deficient tumor is a judgment made by a pathologist who sees these regularly rather than occasionally. Access to that expertise is part of what a specialist referral actually buys.
He is certified by the American Board of Surgery in General Surgery and in Colorectal Surgery, a Fellow of the American College of Surgeons, and a member of the Society of Surgical Oncology and the American Society of Clinical Oncology. He practises with the Surgery Group of Los Angeles.
Questions About Your Pathology Report
Every one of these is answerable from documents that already exist. Vague answers are themselves informative.
- Was CD117 tested, and what was the result?
- If CD117 was negative, was DOG1 tested?
- Was SDHB staining performed?
- What is the mitotic index, and per what area was it counted?
- Was mutation testing done, and which subtype?
- Which risk category does that put me in?
- Has a sarcoma pathologist reviewed the slides?
- Can my slides be sent for a second read?
What Patients Say
Reviews left by patients treated by Dr. Ellenhorn at the Surgery Group of Los Angeles.
★★★★★I was very pleased with the office staff, they were always very pleasant and helpful. I was very impressed with Dr. Ellenhorn as well. He was very friendly and addressed all my concerns regarding my surgery and aftercare and follow up.
Terry Jackson
★★★★★The staff at the Surgery Group of Los Angeles are wonderful. They are kind, very attentive, the office is clean and I did not have to wait long at all. I cannot say enough great things about Dr. Ellenhorn. He is an excellent surgeon who is highly skilled and very knowledgeable. I cannot thank him enough for all he has done for my family and I.
Erika Frank
Thirty Minutes From Burbank
The 134 west to the 101, south through the Cahuenga Pass, then Highland down and west along 3rd Street is the standard route. Laurel Canyon over the hill to Fairfax works when the freeways are congested, and from the Media District end, Hollywood Way to Barham to the 101 is often quicker than it looks.
The office sits in the medical plaza attached to Cedars-Sinai Medical Center, where the pathology department and operating rooms are in the same building as the consultation. For a diagnostic question that depends on slides being retrieved, reviewed, and discussed, that proximity removes most of the delay.
Patients travelling from outside the region, including Arizona and Nevada, can have pathology and imaging reviewed remotely.
8635 W 3rd St, Suite 880W
Los Angeles, CA 90048
Monday to Saturday, 11:00am to 8:00pm
Closed Sunday
Frequently Asked Questions
Could my GIST diagnosis be wrong?
What is CD117 and why does it appear on my report?
My report says CD117 negative. Does that mean it is not a GIST?
What does SDH-deficient mean?
Is it worth having my slides reviewed again?
How far is your office from Burbank?
Can you obtain my slides from a Burbank hospital?
Does the diagnosis change the operation?
Make Sure It Is Actually a GIST.
If your pathology report does not mention CD117 or DOG1, or if the mitotic index is missing, the diagnosis is incomplete. A second read of existing slides settles it without a single new procedure.
