Gastrointestinal stromal tumour with osteoclast-like giant cells and aneurysmal bone cyst-like features

Malignant Phyllodes Tumor Including Aneurysmal Bone Cyst-Like Areas in Pregnancy - a Case Report and Review of the Literature

BACKGROUND

Malignant phyllodes tumors of the breast are rare biphasic neoplasms. Only few cases related to pregnancy have been reported.

CASE REPORT

A 37-year-old woman presented with swelling and pain in her left breast as well as hyperemia on the breast skin, 4 weeks after labor. In her family history, her aunt and maternal cousin had had a breast cancer diagnosis. Clinical evaluation of the patient was consistent with a breast abscess. Therefore, abscess drainage and biopsy from the cavity wall were performed. However, the biopsy was diagnosed as malignant phyllodes tumor. An evaluation by ultrasonography showed a well-defined hypoechoic mass with many cystic spaces covering the entire breast tissue. Therefore, a simple mastectomy was performed. Microscopic examination revealed a high-grade malignant phyllodes tumor. Additionally, bone cyst-like areas in the form of sponge-like blood-filled non-endothelialized spaces were observed.

CONCLUSIONS

Since the breasts become larger due to the physiological changes during pregnancy, any underlying breast lesions may be obscured. Therefore, clinical breast examination in the first visit of pregnancy is important.

Gastrointestinal stromal tumor of the ampulla of Vater with osteoclastic giant cells, osteoid-like matrix deposition, and aneurysmal bone cyst-like features

Gastrointestinal stromal tumors are a heterogeneous group with a wide spectrum of histologic features. We describe the first case of 61-year-old woman who presented gastrointestinal stromal tumors of the ampulla of Vater with osteoclast-like giant cells surrounding osteoid-like material and aneurismal bone cyst-like areas. The phenotype was supported by light microscopy and corroborated by immunohistochemistry analysis. Because of the presence of osteoid-like and aneurismal bone cyst-like components, it is first necessary to make differential diagnosis with other entities such as metastatic osteosarcoma. Our case shows another form of differentiation that has not previously been reported.