Hypoglycemia Observed on Continuous Glucose Monitoring Associated With IGF-2-Producing Solitary Fibrous Tumor.
BACKGROUND
Tumors producing IGF-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, after resection of an IGF-2-producing solitary fibrous tumor of pleura and review the current literature.


METHODS
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, the 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. Continuous glucose monitoring 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%) patients experienced tumor recurrence or metastasis an average of 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.
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Sonoko
S
Otake
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Takuma
T
Kikkawa
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Miho
M
Takizawa
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Junko
J
Oya
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Ko
K
Hanai
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Nobue
N
Tanaka
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Junnosuke
J
Miura
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Izumi
I
Fukuda
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Masato
M
Kanzaki
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Tatsuo
T
Sawada
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Naomi
N
Hizuka
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Takamasa
T
Onuki
Diabetes Center (S.O., M.T., J.O., K.H., N.T., J.M., Y.U.) and Departments of Surgery I (T.K., M.K., T.O.), Pathology I (T.S.), and Medicine II (I.F., N.H.), Tokyo Women's Medical University School of Medicine, 162-8666 Tokyo, Japan.
Yasuko
Y
Uchigata
D000368:Aged; D015190:Blood Glucose Self-Monitoring; D005260:Female; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000175:diagnosis* / Q000209:etiology* / Q000601:surgery; D007335:Insulin-Like Growth Factor II / Q000378:metabolism*; D009384:Paraneoplastic Endocrine Syndromes / Q000097:blood / Q000150:complications* / Q000601:surgery; D054364:Solitary Fibrous Tumors / Q000097:blood / Q000150:complications / Q000378:metabolism* / Q000601:surgery
D007335:Insulin-Like Growth Factor II