Gastric glomus tumor is a rare mesenchymal tumor arising from modified smooth muscle cells (glomus bodies), accounting for 1-2% of all gastric mesenchymal tumors. It typically presents as a small (<3 cm), well-defined, hypervascular submucosal mass in the gastric antrum. It is more common in women than men (2-3:1) with a mean age of diagnosis of 50-60 years. On CT, a small intramural mass with prominent homogeneous enhancement in the arterial phase is characteristic — this enhancement pattern results from the lesion's rich capillary network. On MRI, it shows T2 hyperintense, T1 isointense or mildly hyperintense signal with early intense enhancement on dynamic contrast series. On endoscopic ultrasound (EUS), it appears as a well-defined, hypoechoic submucosal mass related to the muscularis propria layer. The vast majority of gastric glomus tumors have a benign course; however, malignant transformation has been reported in rare cases. Surgical excision is curative.
Age Range
40-80
Peak Age
60
Gender
Female predominant
Prevalence
Rare
Glomus tumor originates from glomus bodies (Suquet-Hoyer canals) involved in thermoregulation at arteriovenous anastomoses. Normal glomus bodies are found primarily in peripheral regions such as fingertips and nail beds; glomus-like cells are also rarely present in the gastric wall. Histologically, the tumor consists of uniform, round glomus cells (modified perivascular smooth muscle cells) and a dense capillary network surrounding these cells. Rich capillary vascularization underlies the lesion's prominent arterial enhancement on CT and MRI: despite its small size, the dense capillary bed leads to rapid contrast material accumulation. The hypoechoic appearance related to muscularis propria on EUS reflects the smooth muscle origin of tumor cells. T2 hyperintensity results from the high water content of myxoid stroma between tumor cells. Alpha-smooth muscle actin (alpha-SMA) and type IV collagen positivity supports perivascular smooth muscle origin, while CD117 (c-kit) negativity differentiates it from GIST.
A small, well-defined submucosal mass in the gastric antrum showing prominent homogeneous enhancement in arterial phase — highly suggestive finding for glomus tumor. This enhancement pattern results from the rich capillary network and is important for differentiation from other submucosal tumors at the same location (GIST, schwannoma, leiomyoma).
In CT arterial phase, a small, well-defined submucosal mass in the gastric antrum demonstrates prominent homogeneous enhancement. Enhancement intensity may approach that of the aorta or adjacent arteries — reflecting the extreme hypervascular nature of the lesion. Homogeneous enhancement pattern differs from the heterogeneous enhancement of GIST.
Report Sentence
A [size] mm well-defined submucosal mass in the gastric antrum demonstrates prominent homogeneous arterial phase enhancement, consistent with glomus tumor.
In portal venous phase, the lesion maintains enhancement but intensity slightly decreases compared to arterial phase — showing slow washout pattern. This persistent enhancement reflects prolonged contrast retention in the tumor's rich capillary bed. Lesion borders remain well-defined and distinctly separated from surrounding gastric wall.
Report Sentence
In portal venous phase, the lesion demonstrates persistent enhancement with slow washout pattern.
On MRI T2-weighted sequences, a well-defined, homogeneously hyperintense submucosal mass is observed in the gastric antrum. T2 hyperintensity reflects the high water content of myxoid stroma between tumor cells. Mass size is usually small (<3 cm) with sharply delineated borders.
Report Sentence
On MRI T2-weighted sequence, a [size] mm homogeneously hyperintense, well-defined submucosal mass is identified in the gastric antrum.
On T1-weighted sequences, the lesion shows isointense or mildly hyperintense signal relative to gastric wall. T1 hyperintensity may reflect the proteinaceous stromal content. On dynamic contrast-enhanced T1 series, early arterial phase enhancement with subsequent slow washout pattern is observed.
Report Sentence
On MRI T1-weighted sequence, the lesion shows isointense/mildly hyperintense signal relative to surrounding tissue, with early intense enhancement on dynamic contrast series.
On endoscopic ultrasound (EUS), a well-defined, homogeneously hypoechoic submucosal mass is observed in the gastric antrum. The lesion originates from the muscularis propria layer (4th layer). Borders are sharp and regular without invasion of surrounding tissue. Color Doppler shows prominent vascularity — intense arterial flow even at small size.
Report Sentence
On EUS, a [size] mm homogeneously hypoechoic, well-defined submucosal mass originating from muscularis propria is identified in the gastric antrum, showing prominent vascularity on color Doppler.
On non-contrast CT, a small, well-defined intramural mass of soft tissue density (30-50 HU) is observed in the gastric antrum. Calcification is rarely seen. Necrosis or cystic degeneration is usually absent — this feature helps differentiate from GIST. The hypervascular nature is not yet apparent on the non-contrast phase.
Report Sentence
On non-contrast CT, a [size] mm well-defined intramural mass of soft tissue density ([value] HU) is identified in the gastric antrum.
Criteria
Most common type; consists of diffuse sheets of glomus cells surrounding sparse capillary vessels. Small, well-defined mass.
Distinct Features
Homogeneous enhancement on CT, homogeneous T2 hyperintense signal on MRI. Vascular component not dominant; cellular component is predominant.
Criteria
Contains prominent vascular component; glomus cells are found between dilated vascular channels. Hemangioma-like structure.
Distinct Features
More prominent arterial enhancement and delayed enhancement persistence on CT. Marked T2 hyperintensity on MRI, dilated vascular structures may be visible as flow voids.
Criteria
Contains glomus cells, vascular structures, and prominent smooth muscle component. Shows histological features overlapping with leiomyoma.
Distinct Features
May show less prominent enhancement than other variants on CT and MRI. More prominent relationship with muscularis propria on EUS. SMA is more strongly positive on immunohistochemistry.
Distinguishing Feature
GIST usually >3 cm, heterogeneous enhancement, may contain necrosis/cavitation, CD117 positive; glomus tumor small (<3 cm), homogeneous enhancement, CD117 negative
Distinguishing Feature
Schwannoma S100 positive, SMA negative; glomus tumor S100 negative, SMA positive — schwannoma may show more pronounced T2 hyperintensity and peripheral lymphoid cuff on MRI
Distinguishing Feature
Carcinoid tumor usually mucosal/submucosal small polypoid lesion, shows arterial phase enhancement but not as hypervascular as glomus tumor; carcinoid chromogranin A positive
Distinguishing Feature
Leiomyoma shows moderate homogeneous enhancement, not as markedly hypervascular as glomus tumor; both SMA positive but collagen IV more prominent in glomus tumor
Urgency
routineManagement
surgicalBiopsy
NeededFollow-up
specialist-referralThe vast majority of gastric glomus tumors have a benign course and surgical excision is curative. Laparoscopic gastric wedge resection is the preferred surgical technique. Malignancy criteria (Folpe): deep location, >2 cm size, atypical mitotic figures, or mitoses ≥5/50 HPF. Tumors meeting any of these criteria carry risk of malignant glomus tumor ('glomangiosarcoma') and require more aggressive surgical approach + follow-up. EUS-guided fine needle aspiration may be diagnostic but definitive diagnosis usually requires post-resection histopathology + immunohistochemistry.
Gastric glomus tumor is benign with extremely rare malignant transformation. Surgical resection is curative. Endoscopic biopsy should be performed carefully due to risk of excessive bleeding.