Objective and importance: Invasion of trigeminal and facial perineural spaces is a recognized complication of cutaneous malignancies. Centripetal spread along the trigeminal nerve axis and into the cavernous sinus and the gasserian ganglion is rare. Metastasis to the leptomeninges and cauda equina has not been reported. We report a unique case of perineural spread and central dissemination from an epithelial squamous cell carcinoma (SCC) associated with a tumor biomarker.
Clinical presentation: After excision of multiple cutaneous SCCs and basal cell carcinomas of the head and neck, a 70-year-old male patient developed successive, right-side, V1 and V2 trigeminal neuropathies and complete right cavernous sinus syndrome during a 5-year period. Concurrently, the right face became paralyzed. Left facial paresis developed during the latter half of this period. Two months before admission, subacute left lower-extremity radicular weakness resulted in falls. Serial magnetic resonance imaging scans obtained in the previous 4 years were unrevealing. At the time of admission, enhancing masses were found in the 1) right cavernous sinus and dura, foramina ovale and rotundum, and Meckel's cave, 2) right subtemporal region and orbital rectus muscles, and 3) cauda equina. Cerebrospinal fluid analysis demonstrated mild pleocytosis and rare carcinoma cells.
Intervention: Biopsy of the right cavernous sinus mass confirmed moderately differentiated, metastatic SCC. Immunohistochemical staining and fluorescence in situ hybridization revealed epidermal growth factor receptor overexpression and genomic amplification.
Conclusion: The indolent progression of cranial nerve palsy among patients with resected cutaneous SCCs of the head and neck must raise clinical suspicion of perineural spread, even in the absence of radiological changes. Biomarkers predicting aggressive SCC behavior, illustrated here by epidermal growth factor receptor amplification and central invasion, have the potential to guide early therapy.