Intracranial epidermoid tumor after subcutaneous lipoma excision

Primary Intracranial Epidermoid Carcinoma with Diffuse Leptomeningeal Carcinomatosis: Report of Two Cases

BACKGROUND

Malignant degeneration of epidermoid cyst (EC) with accompanying leptomeningeal carcinomatosis (LC) at presentation is extremely rare. We add two cases to the literature, including the first case of primary brainstem involvement with simultaneous diffuse LC, and discuss clinical and radiological cues to differentiate benign and malignant epidermoid tumors for early diagnosis.

CASE DESCRIPTION

The first patient in this report was a 54-year-old woman with recurrent aseptic meningitis and hydrocephalus. Imaging revealed a prepontine and parapontine extra-axial EC with an intra-axial brainstem ring-enhancing cystic lesion, diffuse leptomeningeal enhancement, and intradural extramedullary nodular deposits throughout the spine. Surgical decompression of the cysts confirmed the diagnosis of invasive primary squamous cell carcinoma of the brainstem and benign epidermoid tumor of the cerebellopontine cistern. The second patient was a 37-year-old woman with extensive left-sided cranial neuropathies. Imaging revealed prepontine and parapontine enhancing and nonenhancing deposits along multiple cranial nerves and diffuse leptomeningeal nodular enhancement in the thoracolumbar spine. A biopsy confirmed the diagnosis of infiltrative, poorly differentiated carcinoma adjacent to a benign EC. Both patients underwent systemic screening to rule out metastatic disease.

CONCLUSIONS

These cases illustrate that a high index of clinical suspicion is necessary for early diagnosis of disseminated disease in cases of recurrent episodes of aseptic meningitis. In cases of primary benign EC, aggressive resection should be attempted to reduce the risk of malignant degeneration. A separate biopsy specimen from the enhancing portion of the tumor is used to rule out an underlying coexisting malignancy. Multimodal management carries the best prognosis for primary intracranial squamous cell carcinoma with LC.

An analysis of intracranial epidermoid tumors with malignant transformation: treatment and outcomes

OBJECTIVE

While typically benign, epidermoid tumors upon rare occasion can undergo malignant transformation, which carries a poor prognosis. Here, we reviewed treatment strategies and analyzed outcomes for every case of malignant epidermoid tumor reported since its original description in 1912.

METHODS

A comprehensive literature review identified all reported cases of malignant transformation of intracranial epidermoid tumor. Treatments were categorized as follows: palliative management, stereotactic radiosurgery (SRS), chemotherapy, and surgery plus multiple (2+) adjuvant therapies. Survival data of these groups were compared to treatment outcomes for patients receiving only surgical resection, as reported in our previous study.

RESULTS

We identified 58 cases of intracranial epidermoid tumor with malignant degeneration. Average survival regardless of therapy was 11.8 months. Mean survival outcomes for groups treated with palliative management, chemotherapy, SRS, and multiple postoperative adjuvant therapies were 5.3 months, 25.7 months, 29.2 months, and 36.3 months, respectively. Outcomes for the groups including SRS, chemotherapy, and multiple post-operative adjuvant therapies were statistically significant compared to surgical resection alone.

CONCLUSION

While there remains a lack of consensus regarding the best approach to the management of patients with malignant epidermoid tumors, our systematic analysis characterizes and confirms the added benefit of SRS, chemotherapy, and multimodal adjuvant therapies.