Functional endoscopic sinus surgery (FESS) is a treatment of choice for fungal sinus ball (mycetoma), which is considered safe with a very low major complication rate. We present an unusual case of a 12-year-old female, who underwent FESS for a sphenoid sinus mycetoma and which was complicated by an acute, compressive epidural fluid collection. This presumably resulted from sinus irrigation in the setting of an under-appreciated skull base and mucosal defects causing a ball-valve effect. Our patient had a temporary neurologic deficit with complete recovery, however, similar complications can have fatal consequences.

中文翻译：

---

硬膜外压缩性收集是小儿肌瘤的FESS异常并发症。

功能性内窥镜鼻窦手术（FESS）是真菌性鼻窦球（粘膜瘤）的一种选择治疗方法，这种方法被认为是安全的，主要并发症的发生率非常低。我们介绍了一名12岁女性的不寻常病例，该女性因蝶窦肌瘤接受了FESS治疗，并因急性，压缩性硬膜外积液而变得复杂。这大概是由于鼻窦冲洗导致颅底欠佳和粘膜缺损引起的球阀效应所致。我们的患者暂时性神经功能缺损，完全康复，但是，类似的并发症也可能导致致命的后果。