Malignant Granular Cell Tumor of the Skull Base

Abstract

Objective and Importance: Malignant granular cell tumors (MGCTs) are extremely rare, high-grade sarcomas of Schwann cell origin. They often metastasize and are associated with short survival. We describe a patient with a large MGCT arising from the suboccipital nerve that eroded the posterior skull base, invaded the perifocal neck muscles, demonstrated perineural extension, and metastasized to regional lymph nodes. Clinical Presentation: A 60-year-old woman with several years' history of neck pain noticed a right-sided suboccipital swelling 4 months prior to seeking medical attention. Magnetic resonance imaging (MRI) showed a 5-cm boneeroding suboccipital tumor and a second tumor, anterocaudal to this, 4 cm in diameter. Intervention: The patient underwent surgery. A 4-cm multinodular tumor was removed, freeing it from the internal jugular vein. A 5-cm suboccipital tumor infiltrated the trapezius, semispinalis capitis, and longissimus capitis muscles. The major and minor rectus capitis muscles were completely engulfed by tumor and their attachments to the occipital bone completely eroded. The oblique capitis muscle was infiltrated at its attachment to the C1 transverse process. These muscles were resected with a free margin to remove all tumor tissue. We then removed tumor encasing the right vertebral artery, the medial mastoid process up to the transverse sinus and anteriorly to the stylomastoid foramen, and lastly, the posterior third of the occipital condyle, achieving a gross total removal and no visible residual on postoperative contrast-enhanced MRI. Conclusion: This case represents the first report of resected primary MGCT involving the posterior fossa and arising from the suboccipital nerve.

Atypical granular cell tumor in the maxilla: The first report of primary intraosseous granular cell tumor

“…In a review of 53 metastatic GCT cases, bone metastases were reported in 9 cases . There has also been 1 case report of malignant GCT arising from the suboccipital nerve and eroding the posterior skull base . However, there had been no reports of primary GCT arising within the bone, making the present case the first report of a primary intraosseous GCT.…”

Mohs Surgical Excision of a Granular Cell Tumor with Plexiform Features on the Arm of a 7-Year-Old Child

“…Although a few cases of GCT with perineural involvement and a plexiform growth pattern have been described in the literature, none of them were treated with MMS 37–40 . In 1994, Lee and colleagues published a report of two cases of “a previously undescribed variant of GCT with an interesting plexiform pattern.” 41 One case was found on the lower leg of a 10‐year‐old girl, and the other was on the back of a 12‐year‐old girl.…”