Malignant Perivascular Epithelioid Cell Tumor Mimicking Jugular Foramen Schwannoma: A Case Report and Literature Review

Objectives: Perivascular epithelioid cell tumor of the skull base is extremely rare. This tumor can behave malignantly. The present report provides the first description of a malignant perivascular epithelioid cell tumor mimicking jugular foramen schwannoma presenting as Collet-Sicard syndrome. In 2002, the World Health Organization recognized the concept of perivascular epithelioid cell tumor as a family of neoplasms including renal and hepatic angiomyolipoma; pulmonary lymphangioleiomyomatosis; clear cell “sugar” tumors of the lung, pancreas, and uterus; and clear cell myomelanocytic tumors of the hepatic falciform and teres ligaments. This tumor can arise from many anatomic locations. Among them, the skull base is extremely rare. The tumor in the present case mimicked jugular foramen schwannoma, making treatment decisions extremely difficult. We herein present this case along with a literature review of malignant perivascular epithelioid cell tumor of the skull base region.

Study Design: Case report and literature review.

Case Presentation: A 29-year-old woman presented with hoarseness, dysphagia, vomiting, and headache. Physical examination in our neurology department also revealed paralysis of the right hypoglossal and accessary nerves. Furthermore, computed tomography of the head and neck revealed an interruption of flow in the right sigmoid and transverse sinuses with no apparent tumor. She was diagnosed with Collet-Sicard syndrome by thrombosis of the sigmoid and transverse sinuses. She was treated with anticoagulant therapy, and the hoarseness and paralysis of the accessory nerve improved. The hoarseness worsened at the age of 31 years. In another hospital, enhanced computed tomography revealed a tumor immediately below the jugular foramen, extending into the jugular foramen and displacing the internal carotid artery medially. She was referred to our hospital for further examination of this tumor. The tumor was investigated by contrast-enhanced computed tomography and magnetic resonance imaging, and she was diagnosed with jugular foramen schwannoma causing thrombosis of the sigmoid and transverse sinuses. During a 1-year follow-up, the tumor grew rapidly and the clinical course was not typical for a jugular foramen schwannoma. We decided to perform a tissue biopsy of the tumor in the jugular foramen and neck. Pathological analysis revealed a malignant perivascular epithelioid cell tumor. After discussing treatment options with otorhinolaryngologists, a radiologist, and an oncologist, we chose to perform surgical treatment first. We applied a postauricular transtemporal approach to remove the tumor, resulting in subtotal resection of the tumor. Six months after surgery, radiotherapy was added to treat the residual tumor.

Conclusion: The optimal treatment strategy for malignant perivascular epithelioid cell tumor remains controversial, and surgical removal is still the first option. It may be extremely challenging to reach an accurate diagnosis of this tumor in the skull base region, which may cause a delay in the start of treatment. The radiological findings in this case were extremely similar to those of jugular foramen schwannoma; however, the clinical course was not typical of schwannoma. When atypical clinical features of a skull base tumor are found, preliminary biopsy should be recommended to obtain a definitive diagnosis and start a proper treatment strategy as early as possible.