Malignant granular cell tumor: Clinical features and long-term survival.

BACKGROUND

Malignant granular cell tumor GCT (mGCT) has not been well described. We sought to investigate associations between tumor characteristics, treatments and survival.

METHODS

Patients diagnosed with mGCT years 1995-2014 were identified using the Surveillance, Epidemiology and End Results database. Descriptive statistics regarding tumor and treatment characteristics were calculated. Chi-square tests determined associations between tumor location and features. Survival analyses included Kaplan-Meier functions and Cox proportional hazard ratios (HR).

RESULTS

Of 113 patients included, median age was 54 years and 77.0% were female. Frequent tumor sites included soft tissues (36.3%), ovary/testis (16.8%), and skin (11.5%). Median tumor size was 4.0 cm. Metastases to regional lymph nodes (12.5%) and distant sites (11.4%) occurred. Treatments included surgery (85.0%), radiotherapy (12.4%) and chemotherapy (8.9%). Overall five and 10-year cause-specific survival was 74.3% and 65.2%, respectively. Survival was worse for patients with tumors >5 cm compared to those with tumors ≤5 cm (HR = 34.03; 95% confidence interval [CI]: 2.57-450.17), and patients with metastasis (HR = 15.25; 95% CI: 1.19-195.72) compared with those without metastasis. Patients who underwent surgery had superior survival than those who did not (HR = 0.13; 95% CI: 0.05-0.34).

CONCLUSIONS

Particular tumor features and treatments are associated with superior survival. This information may be used to more accurately estimate prognosis.