Abstract
INTRODUCTION: Ewing sarcomas (ES) are rare but aggressive tumors composed of small, round, undifferentiated embryonal-type cells that arise in bone and soft tissues. Here, we report a case of primary sellar/suprasellar Ewing sarcoma in a 31-year-old man. CLINICAL CASE: A 31-year-old male patient presented with progressive visual impairment, headache, and decreased libido. One year ago, the patient had a work accident resulting in traumatic amputation of the three fingers of the right hand, after which bilateral peripheral visual field loss was detected. In the last three months, he developed decreased sexual desire and erectile dysfunction, and the visual symptoms worsened gradually in the previous month. The patient’s past medical and family history were unremarkable. The physical examination was normal, except for the presence of visual field constriction. Laboratory tests revealed central hypothyroidism and hypogonadotropic hypogonadism, and the prolactin level was 30 ng/dl (2,1-17,2) IGF-1 was normal (81,6).(Table 1). Visual field testing revealed bilateral temporal hemianopsia. Magnetic resonance imaging (MRI) of the sellar region revealed a sellar/suprasellar mass lesion (Figure 1). The patient underwent transsphenoidal surgery with perioperative steroid coverage. Postoperatively, marked improvement was noted in headache and visual complaints; however, anterior pituitary insufficiency persisted, and diabetes insipidus developed. Hormone replacement therapy was initiated with methylprednisolone, levothyroxine and desmopressin. Histopathological examination demonstrated hypercellular, round-cell neoplastic infiltration with a Ki-67 proliferation index of 20%. Immunohistochemical analyses revealed strong focal positivity for synaptophysin and pan-cytokeratin, positivity for Mic-2 and NKX2.2, while GFAP, TTF1, and pituitary hormones were negative. Since NKX2.2 is seen in Ewing sarcoma, EWSR1 gene rearrangement was examined by fluorescence in situ hybridization (FISH) for definitive diagnosis and found positive. The histopathologic findings were consistent with Ewing sarcoma. A whole body 18F-FDG PET/CT scan was performed to differentiate the primary sellar lesion from metastatic disease. No abnormal FDG uptake was detected and therefore the lesion was considered primary sellar Ewing sarcoma. Postoperatively, the patient was referred to oncology for adjuvant chemo-radiotherapy. A brain MRI performed nine months after surgery revealed no evidence of recurrence. CONCLUSION: Ewing sarcoma in the sellar region is extremely rare and is usually found as a metastasis of the primary tumor. The case presented here is unique because it is a primary sellar Ewing sarcoma confirmed by molecular analysis and only one such case has been reported in the literature. Differentiation of these tumors from other more common sellar/suprasellar tumors, including pathological, immunohistochemical and genetic studies, is very important as it can completely change the treatment approach. [Figure: see text] [Figure: see text]