The relation between variation in size of the primordial follicle pool and age at natural menopause

Context:
Tumors producing insulin-like growth factor 2 (IGF-2oma) are a major cause of spontaneous hypoglycemia. The treatment mainstay is surgical resection. Many case reports note resolution of hypoglycemia after IGF-2oma resection; however, outcomes are variable according to tumor type. We report a case of resolving hypoglycemia, observed on continuous glucose monitoring (CGM), after resection of an IGF-2-producing solitary fibrous tumor, of pleura and review the current literature.

Case Report:
A 69-year-old woman presented with impaired consciousness because of hypoglycemia. An IGF-2oma was diagnosed as the cause for hypoglycemia because of decreased serum insulin and IGF-1, presence of a pleural tumor, and a high-molecular-weight form of serum IGF-2 detected by western immunoblot. Surgical resection was performed; pathological examination demonstrated a solitary fibrous tumor with low-grade malignancy. CGM showed reversal of hypoglycemia after tumor resection. Approximately 2 years after resection, the patient has no signs of tumor recurrence or hypoglycemia.

Conclusions:
An IGF-2-producing solitary fibrous tumor of pleura in this case caused hypoglycemia. From a search of the literature of 2004–2014, 32 cases of IGF-2oma with hypoglycemia that underwent radical surgery were identified; in 19 (59%) patients, hypoglycemia was reversed and there was no subsequent recurrence. The remaining 13 (41%) experienced tumor recurrence or metastasis and recurrence of hypoglycemia average 43 months after initial tumor resection. The tumor of the present case was a low-grade malignancy. Regular follow-up with biomarker-monitoring of glucose metabolism and assessment of hypoglycemic symptomatology, in conjunction with imaging tests, is important for detecting possible tumor recurrence and metastasis.