Epithelioid gastric stromal tumors (leiomyoblastomas): a study of fifty-five cases.
BACKGROUND
Epithelioid gastric stromal tumors form a distinct histologic subset of gastric tumors whose malignant potential and prognosis are controversial.


METHODS
Fifty-five patients with epithelioid gastric stromal tumors accounted for 11.5% of patients undergoing definitive operations for gastric stromal tumors from 1960 to 1986. Medical records and pathology slides were reviewed, and immunohistochemical staining and flow cytometry were performed. The Kaplan-Meier method was used to estimate survival. Survival curves were compared with log-rank tests and Cox proportional hazards model.


RESULTS
Of the 55 tumors, 40 were benign and 15 (27%) were malignant. Mean follow-up was 10.5 years. Ten patients died of their disease. No patient with a benign tumor had recurrence of metastasis, but all patients with high-grade malignancy had died of disease within 3 years after diagnosis. Seventy-five percent of proximal tumors were malignant. Extent of resection had no impact on survival (p = 0.5).


CONCLUSIONS
The best determinant of tumor behavior was histologic grade. Twenty-seven percent of patients had malignant tumors, and 67% of these died of disease. Other significant prognostic factors included a mitotic count greater than 5/10 high-power fields, size larger than 6 cm, aneuploidy, and higher S-phase fraction (p < 0.01). Proximal lesions were more likely to be malignant. Extent of surgical treatment had no effect on survival.
Lee
J S
JS
Division of Gastroenterologic and General Surgery, Mayo Clinic, Rochester, MN 55905, USA.
Nascimento
A G
AG
Farnell
M B
MB
Carney
J A
JA
Harmsen
W S
WS
Ilstrup
D M
DM
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000782:Aneuploidy; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D005500:Follow-Up Studies; D005743:Gastrectomy; D006801:Humans; D018230:Leiomyoma, Epithelioid / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery; D015993:Life Tables; D008197:Lymph Node Excision; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D009378:Neoplasms, Multiple Primary / Q000453:epidemiology; D010166:Palliative Care; D011183:Postoperative Complications / Q000453:epidemiology; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000453:epidemiology* / Q000473:pathology / Q000601:surgery; D016019:Survival Analysis; D015996:Survival Rate; D016896:Treatment Outcome
D004273:DNA, Neoplasm