Orbital granular cell tumours: clinical and pathologic characteristics of six cases and literature review

Abstract

Objective To retrospectively assess the clinicopathological characteristics of orbital granular cell tumours (GCTs). Methods A non-comparative review of the clinical characteristics, imaging, histopathological features, management, and prognosis of five cases of benign GCT and one case of malignant GCT (MGCT) was conducted, along with a review of the English language literature. Results Among the six cases, four tumours were adherent to the extraocular muscle (EOM), and three tumours to the optic nerve (ON). Morphologic examinations revealed polygonal cells containing periodic-acid-Schiff-positive eosinophilic granules. All tumours (100%) were positive for VIM and NSE, five (83.3%) tumours were positive for S-100, and three (50%) tumours were positive for CD68. The follow-up examination of the MGCT witnessed recurrence and brain metastasis despite several thorough resections, but the patient remained alive; the follow-up examination of the four benign GCTs that had received incomplete excision revealed recurrence in one patient and dramatic shrinkage of the residual tumour in another; there was no recurrence in the other two patients. Conclusions GCT should be considered in the differential diagnosis of orbital tumours, which may affect EOMs and ON. The natural course of GCT can include tumour progression, stability, or spontaneous regression. To avoid recurrence, complete resection is recommended for orbital GCT. To the best of our knowledge, primary orbital MGCT is reported for the first time.

Case report: an intriguing sign in a patient with an inferior rectus muscle granular cell tumor

“…Immunohistochemical studies of the patient was consistent with previous reports [4] that showed 100%, 90%, and 66.7% of cases were positive for vimentin, S-100, and CD68, respectively. Therefore, the final diagnosis was a GCT.…”

“…The chance of postoperative recurrence is low and some spontaneously regress after partial resection. [4,11] However, in patients with preoperative diplopia, diplopia may persiste after surgery. Cases of relapsed and systemic metastases of malignant GCTs are rare.…”

“…Extraocular muscles were involved in 67.5% of the GCTs, with the most common infiltration, 40.7%, of the inferior rectus muscle. [4]…”

Retinal granular cell tumor: a case report

“…The occurrence of GCTs in the eyeball might be correlated with the optic nerve. About 30% of orbital GCTs affect the optic nerve due to tumor adhesion to the optic nerve, which disturbs visual acuity [ 8 ]. Although the optic nerve originates from the central nervous system, it does not consist of Schwann cells.…”

“…Vasoproliferative tumors, which might be confused with GCTs because of a discoid mass with medium to high internal reflectivity on B-scan ultrasonography, show a mix of vascular and glial proliferation in microscopic studies [ 14 ]. Malignant GCTs are even rarer, and about 1–2% of GCTs are malignant [ 8 ]. The Ki-67 index value in this case was 5%, which indicated a benign tumor.…”