Clin Oncol | Volume 6, Issue 1 | Case Report | Open Access

High-Molecular-Weight Insulin-Like Growth Factor II Secreting Phyllodes Tumor of the Breast Presenting as a Hypoglycemic Coma: A Case Report

Yuki Ichinose1, Shigeto Ueda2, Tomonori Kawasaki3, Takanori Hayashi4, Akihiro Fujimoto1, Asami Nukui1, Hiroko Shimada1, Aya Asano5, Kazuo Matsuura1, Takahiro Hasebe1, Akihiko Osaki1* and Toshiaki Saeki1

1Department of Breast Oncology, Saitama Medical University International Medical Center, Japan
2Department of Breast Surgery, JR Tokyo General Hospital, Japan
3Department of Pathology, Saitama Medical University International Medical Center, Japan
4Department of Biochemistry, Fujita Health University School of Medicine, Japan
5Department of Breast Oncology, Saitama Medical University Hospital, Japan

*Correspondance to: Akihiko Osaki 

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We report the case of a patient who presented with a hypoglycemic attack associated with a Phyllodes tumor and the presence of high-molecular-weight Insulin-like Growth Factor II (IGF-II). A 42-year-old premenopausal woman, who had had a palpable mass in her left breast for several months, was found unconscious at her home by a family member early in the morning. She was
emergently transported to our hospital. Her clinical examination revealed an approximately 15-cm mass in the entire left breast. Her blood glucose level was 33 mg/dL, resulting in hypoglycemia, and a 50% glucose injection immediately improved her awareness level. Thoracoabdominal computed tomography demonstrated a large, lobulated left breast tumor showing heterogeneous internal echotexture without enlargement of the lymph nodes (axillary, supraclavicular, cervical, and mediastinum) or distant metastasis. We performed a vacuum-assisted needle biopsy of the breast lesion that showed a Phyllodes tumor. We performed mastectomy, including the tumor, and the patient recovered from the hypoglycemic episode. The histological  examination revealed a borderline Phyllodes tumor. Immunohistochemical examinations revealed neoplastic cells diffusely positive for IGF-II. Moreover, Western blot analysis demonstrated large amounts of highmolecular-weight IGF-II in the resected tumor. No relapse of a hypoglycemic attack and tumor recurrence has been reported post-surgery.


Non-islet cell tumor hypoglycemia; Insulin-like growth factor type II; Hypoglycemic coma


Ichinose Y, Ueda S, Kawasaki T, Hayashi T, Fujimoto A, Nukui A, et al. High-Molecular-Weight Insulin-Like Growth Factor II Secreting Phyllodes Tumor of the Breast Presenting as a Hypoglycemic Coma: A Case Report. Clin Oncol. 2021;6:1800..

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