Low-Grade Fibromyxoid Sarcoma of the Lateral Skull Base: Presentation of Two Cases

Abstract

Low-grade fibromyxoid sarcoma (LGFMS) is a rare slow-growing malignant tumour with a deceptively benign histologic appearance. Herein, we report two cases of LGFMS with variable clinical presentations. The first case was a 17-year-old female who referred to our department due to deaf ear on the right together with ipsilateral gag reflex impairment and globus sensation in the pharynx. The second case was a 35-year-old female with recurrent LGFMS, suffering from headaches, vertigo, and episodes of loss of consciousness. LGFMS of the temporal bone is a rare pathology, and to the best of our knowledge, no such cases have been reported before.

Figure 1

Pre- and postoperative MRI scans of Case 1. (a) Preoperative MRI T2 sequence showing the tumour measuring 25 × 20 mm at the jugular foramen with infralabyrinthine extension causing erosion of the posterior semicircular canal. Note clear distinction between the tumour and cerebellum posteriorly. (b) Preoperative MRI T1 with gadolinium enhancement. (c) Intraoperative picture after extended mastoidectomy and neck dissection. The next step was anterior rerouting of the facial nerve, which gives required access to the jugular foramen. (d) Postoperative MRI T1 with gadolinium enhancement after 3 years of follow-up. Total tumour clearance and no evidences of recurrence could be confirmed.

Figure 2

Histopathological features of LGFMS. (a) Fibrous stroma containing myxoid parts and whorling spindle cells (H&E × 100) (b) Tumour cells show diffuse reactivity for MUC4. (c) LGFMS with alternating fibrous and myxoid areas (H&E × 100). (d) Tumour cells show strong cytoplasmic staining for MUC4.

Figure 3

Pre- and postoperative CT and MRI scans of Case 2. (a) Preoperative CT scan showing calcifications within the tumour. (b) Preoperative MRI showing a large arachnoid cyst posteriorly to the tumour at the right cerebellopontine angle. Note remarkable compression of the cerebellum and brainstem caused by the cyst. (c, d) Preoperative MRI scans showing tumour masses in the right parapharyngeal space and at the projection of the temporal bone, respectively. (e, f) Postoperative MRI scans showing fat tissue at the right parapharyngeal space and at the projection of the temporal bone, respectively.