Esophagus
Other tumors
Gastrointestinal stromal tumor
Authors: Feriyl Bhaijee, M.D., Israh Akhtar, M.D.
Topic Completed: 1 August 2013
Minor changes: 21 December 2020
Copyright: 2003-2021, PathologyOutlines.com, Inc.
PubMed Search: Gastrointestinal stromal tumor esophagus free full text[sb]
Table of Contents
Definition / general | Terminology | Epidemiology | Sites | Etiology | Clinical features | Diagnosis | Radiology description | Radiology images | Prognostic factors | Case reports | Treatment | Clinical images | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Positive stains | Negative stains | Electron microscopy description | Electron microscopy images | Molecular / cytogenetics description | Differential diagnosis | Additional referencesCite this page: Bhaijee F, Akhtar I. Gastrointestinal stromal tumor. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/esophagusGIST.html. Accessed January 22nd, 2021.
Definition / general
- Mesenchymal tumor of digestive tract, likely originating from multipotential progenitors of interstitial cells of Cajal
Terminology
- Microscopic GIST: sporadic interstitial cell of Cajal hyperplasia, seedling GIST, minimal GIST
Epidemiology
- Very rare: < 3% of all GIST arise in esophagus
- No gender predilection
- Wide age range, average 50 - 60 years
- May be incidental finding in patients undergoing resection of upper GI neoplasms (Can J Surg 2012;55:366)
Sites
- Mid to lower esophagus
Etiology
- Mostly sporadic
- Higher incidence in patients with
- Neurofibromatosis type I (NF1, von Recklinghausen disease)
- Carneys triad
- Familial GIST syndrome: rare, autosomal dominant genetic disorder, characterized by germline KIT or PDGFRA mutations, early onset of multiple GIST tumors, skin pigmentation abnormalities (Am J Surg Pathol 2013;37:898)
Clinical features
- Esophageal mass, stricture, perforation
- Dysphagia
- Metastatic spread to liver and peritoneum
Diagnosis
- Biopsy with immunohistochemical / molecular confirmation
Radiology description
- CT / MRI: useful for preoperative and metastatic evaluation
- Well circumscribed, hypoattenuating mass (Cancer Imaging 2012;12:100)
- PET: FDG avidity
- Used to monitor response to tyrosine kinase inhibitor therapy
- Barium studies: smooth intraluminal mass or large ulcerative mass extending intraluminally
- Endoscopic ultrasound: enables image guided core needle biopsy or fine needle aspiration
Radiology images
Images hosted on other servers:
40 year old man with dysphagia
Enhancing chest CT
CT scan shows well circumscribed tumor
Prognostic factors
- Risk stratification based on size and mitotic activity per 50 high power fields (HPF):
- Low risk: < 5 cm and < 5/50 HPF
- Intermediate risk: < 5 cm and 6 - 10/50 HPF OR 5 - 10 cm and < 5/50 HPF
- High risk: > 5 cm and > 5/50 HPF OR > 10 cm and any mitotic rate OR any size and > 10/50 HPF
| Risk category | Tumor size | Mitotic rate/50 HPF |
|---|---|---|
| Low | < 5 cm | < 5 |
| Intermediate | < 5 cm | 6 - 10 |
| Intermediate | 5 - 10 cm | < 5 |
| High | > 5 cm | > 5 |
| High | > 10 cm | Any mitotic rate |
| High | Any size | > 10 |
Case reports
- 39 year old man with esophageal perforation (Int J Surg Case Rep 2013;4:636)
- 53 year old man with pulmonary and bone metastases (Diagn Interv Radiol 2010;16:217)
- 57 year old man with germline KIT mutation (Arch Pathol Lab Med 2007;131:1393)
- 57 year old HIV+ man with metastatic GIST (Ann Diagn Pathol 2005;9:49)
- 58 year old woman with GIST invading lung parenchyma (J Cardiothorac Surg 2008;3:31)
- 62 year old man with large esophageal GIST (J Natl Med Assoc 2009;101:462)
- 74 year old man with synchronous squamous cell carcinoma and thoracic GIST (World J Surg Oncol 2008;6:116)
Treatment
- Surgical resection
- Neoadjuvant small molecule tyrosine kinase inhibitors: imatinib mesylate (STI571, Gleevec), sunitinib maleate
Clinical images
Images hosted on other servers:
Endoscopic images
Gross description
- Lobulated, well circumscribed mass with fleshy cut surfaces
- Cystic degeneration, necrosis, hemorrhage common
- Overlying esophageal mucosa may be ulcerated
Gross images
Images hosted on other servers:
19 cm tumor with cystic degeneration and necrosis
Multinodular,
well circumscribed
mass in posterior
mediastinum
Microscopic (histologic) description
- Histologic heterogeneity:
- Spindle cell type (70%): relatively uniform eosinophilic cells in short fascicles or whorls, indistinct cell borders, paranuclear cytoplasmic vacuoles, stromal lymphocytes and microcystic stromal degeneration (as in schwannoma), minimal collagen, delicate thin walled vessels, stromal hemorrhage
- Epithelioid type (20%): rounded cells with variably eosinophilic or clear cytoplasm in nests or sheets, uniform round / ovoid nuclei with vesicular chromatin
- Mixed type (10%): may have abrupt transition between spindle cell and epithelioid areas or complex comingling of both
- Stromal skeinoid fibers (< 20%): hyaline or fibrillary brightly eosinophilic PAS+ structures, representing nodular tangles of collagen fibers; more common in small bowel GIST
- Rarely: cytologic atypia, myxoid stroma
- Variable mitotic activity
- Microscopic GIST: < 1 cm, spindle cells with hyalinized stroma and variable calcification (Pathology 2008;40:9)
Microscopic (histologic) images
Images hosted on other servers:
Dense cellularity, mixture of epithelioid and spindled areas
Intramural nodule
and fascicular
arrangement of
spindle cells
H&E
KIT
KIT / CD117
CD117 and desmin
CD117, CD34, SMA, S100
Cytology description
- Cellular monomorphic proliferations of epithelioid or spindle cells
- Round / oval nuclei, vesicular chromatin, fibrillary cytoplasm
- Cohesive fragments with admixed delicate, thin walled vessels
- Features of malignancy: cellular dyscohesion, nuclear pleomorphism, prominent nucleoli, increased mitotic activity, prominent necrosis
Cytology images
Images hosted on other servers:
Spindle cells with high cellularity
Epithelioid cells with round nuclei
Positive stains
Negative stains
Electron microscopy description
- Relative lack of differentiation
- Incomplete smooth muscle or neuroaxonal differentiation
- No bundles of actin filaments (seen in true smooth muscle tumors)
Electron microscopy images
Images hosted on other servers:
Ultrastructural
demonstration of
cytoplasmic vesicles
in high risk GIST
Molecular / cytogenetics description
- Mutually exclusive mutations of activating KIT (95%) or platelet derived growth factor alpha (PDGFRA) receptor tyrosine kinase (5%)
- In frame deletions, point mutations, duplications, insertions
- Most common: KIT juxtamembrane domain (exon 11) mutations
- Confers better response to tyrosine kinase inhibitor therapy
Differential diagnosis
- Carcinoma: cytokeratin+
- Desmoid fibromatosis: beta catenin+, CD117- / +, CD34-
- Inflammatory fibroid polyp: PDGFRA+, CD34+, CD117-, mixed inflammatory infiltrate (especially eosinophils)
- Inflammatory myofibroblastic tumor: ALK rearrangements, CD117-, prominent inflammatory infiltrates
- Leiomyoma / leiomyosarcoma: diffusely SMA+, desmin+, h-caldesmon+; CD117-
- Melanoma: MelanA+, tyrosinase+, MITF+
- MPNST: variable S100+, CD117-
- Schwannoma: diffusely S100+, CD117-
Additional references
