Big muscles and big nerves

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

RATIONALE

Occurrence of granulosa cell tumors (GCTs) in the eye are rare and may be diagnosed by imaging examination and immune-histochemical studies. Two common signs of a rectus muscle tumor are the proptosis of the eye ball and the complaint of bi-ocular diploma.

PATIENT CONCERNS

A 45-year-old man visited our ophthalmology department with an about a 3-year history of vertical diplopia. His visual acuity when looking forward was normal but was severely low when gazing upward.

DIAGNOSIS

Histopathological analysis demonstrated that the encapsulated tumor contained large nested or cord-like cells with small nuclei and abundant eosinophilic cytoplasmic particles. Immunohistochemistry showed that tumor cells strongly expressed CD68, S100 and vimentin, were weakly positive for Ki67, and negative for CK. The tumor was diagnosed as a GCT.

INTERVENTIONS

The tumor was surgically removed via a transconjunctival approach along inferior rectus muscle.

OUTCOMES

The severe loss of acuity when gazing upward was ameliorated after surgery, but global mobility did not improve. Long-term follow-up was still needed.

LESSONS

Ophthalmologists should be aware that when a patient's visual acuity is normal when looking forward but severely low when gazing upward, it may be a sign of a GCT of the inferior rectus muscle.

Imaging studies for diagnosing Graves' orbitopathy and dysthyroid optic neuropathy

Although the diagnosis of Graves' orbitopathy is primarily made clinically based on laboratory tests indicative of thyroid dysfunction and autoimmunity, imaging studies, such as computed tomography, magnetic resonance imaging, ultrasound and color Doppler imaging, play an important role both in the diagnosis and follow-up after clinical or surgical treatment of the disease. Imaging studies can be used to evaluate morphological abnormalities of the orbital structures during the diagnostic workup when a differential diagnosis versus other orbital diseases is needed. Imaging may also be useful to distinguish the inflammatory early stage from the inactive stage of the disease. Finally, imaging studies can be of great help in identifying patients prone to develop dysthyroid optic neuropathy and therefore enabling the timely diagnosis and treatment of the condition, avoiding permanent visual loss. In this paper, we review the imaging modalities that aid in the diagnosis and management of Graves' orbitopathy, with special emphasis on the diagnosis of optic nerve dysfunction in this condition.

Primary optic nerve sheath meningioma: stereotactic fractionated radiation therapy as an emerging treatment of choice

BACKGROUND

Radiotherapy (RT) has occasionally been practiced in the treatment of optic nerve sheath meningioma (ONSM). Recently, stereotactic fractionated RT (SFRT) has been introduced as a tool with better precision for RT delivery. A comprehensive review was undertaken to provide more insight into this matter.

METHODS

A literature search was performed to identify reports dealing with both clinical aspects (diagnosis) and treatment in ONSM, focusing on RT in primary (p)ONSM. In particular, major emphasis was placed on the role of SFRT in pONSM.

RESULTS

SFRT was capable of achieving excellent local tumor control, with improved/stable functional capacity in > or = 80%, accompanied with very low toxicity in meticulously planned RT. This holds true for the majority of patients with progressive functional loss and probably the vast majority of those with some degree of functional loss at presentation. Those blind at presentation benefit from postoperative RT, whereas those with only minimal functional loss at presentation must be carefully selected for the best treatment, because a wait-and-see policy will inevitably lead to serious dysfunction or even blindness.

CONCLUSIONS

SFRT should be considered the treatment of choice for the majority of patients with pONSM. Every effort should be made to further investigate the remaining questions in this disease, such as optimal timing for the patients with no or slight vision loss at presentation.

Papillary Thyroid Carcinoma With Thyroid-associated Orbitopathy in a Euthyroid State

PURPOSE

Thyroid cancers with concurrent thyroid-associated orbitopathy (TAO) are extremely rare. The present study reports 5 unusual cases of papillary thyroid microcarcinoma in patients presenting with TAO in an euthyroid state.

METHODS

We retrospectively reviewed the records of 5 patients (4 female, 1 male) with no known history of thyroid disease, who initially presented with TAO and were subsequently found to have thyroid cancer. TAO was diagnosed by a combination of computed tomography and clinical symptoms and signs. All patients underwent routine serologic assessment of thyroid hormones and thyroid-related autoantibodies including thyrotropin-receptor antibodies, as well as imaging studies such as neck ultrasonography or thyroid scintiscan with I.

RESULTS

Patients presented with asymmetric proptosis (cases 1-3), ocular motility restriction (cases 1-3), and eyelid retraction (cases 1-5). None of the patients showed clinical signs of hyperthyroidism, and all returned normal thyroid function test data. Thyroid nodules were detected by neck imaging; subsequent fine-needle aspiration biopsies were performed with the cytologic result of papillary carcinoma. In no cases did ophthalmic symptoms resolve following cancer treatment (e.g., thyroidectomy and radioactive iodine therapy). All patients were positive for thyroid-binding inhibiting immunoglobulin in low titers.

CONCLUSIONS

Although coincident occurrence is rare, patients presenting with TAO should be carefully evaluated for the possible presence of papillary microcarcinoma, which can develop in a setting of systemic autoimmunity without inducing hyperthyroidism.

Fractionated stereotactic radiotherapy for the treatment of optic nerve sheath meningiomas: preliminary observations of 33 optic nerves in 30 patients with historical comparison to observation with or without prior surgery

OBJECTIVE

We investigated the safety and efficacy of stereotactic radiotherapy as an alternative therapy to surgical resection for optic nerve sheath meningiomas (ONSMs).

METHODS

Thirty patients and 33 optic nerves with ONSMs were treated with conventional fractionated stereotactic radiotherapy treatment (CF-SRT) between July 1996 and May 2001 with the use of a 6-MeV LINAC designed for and dedicated to radiosurgery. The LINAC technique involved daily CF-SRT involving a relocatable frame, an average of three isocenters, and high-radiation dose conformality established by noncoplanar arc beam shaping and differential beam weighting. The patients who were treated with CF-SRT were followed clinically with serial visual fields and radiographically with both magnetic resonance imaging and functional (111)In-octreotide single-photon emission computed tomography. The results of treatment were compared with a historical control group of ONSM patients who were either observed or treated surgically and then observed.

RESULTS

Our study population comprised 18 women and 12 men with a median age of 44 years (age range, 20-76 yr). The median isosurface radiation dose was 51 Gy (dose range, 50-54.0 Gy), and the median clinical follow-up time was 89 weeks (range, 9-284 wk). Of 22 optic nerves with vision before CF-SRT, 20 nerves (92%) demonstrated preserved vision, and 42% manifested improvement in visual acuity and/or visual field at follow-up. Comparison of our patients with a historical control group revealed preserved vision in only 16% of patients in a comparable period of observation, along with a 150% greater probability of visual improvement. Four patients (13%) had posttreatment morbidities, including visual loss (two patients), optic neuritis (one patient), and transient orbital pain (one patient). On magnetic resonance imaging studies, there was no evidence of tumor progression or recurrence in all patients, including tumor volume reductions noted in four patients. All six patients monitored with (111)In-octreotide scintigraphy demonstrated significant decreases in tumor activity after CF-SRT.

CONCLUSION

To date, this article describes the largest reported series of ONSMs. Although longer follow-up is necessary, we think that CF-SRT represents a safe alternative to surgery and offers a higher likelihood of preserved or improved vision in patients with ONSM. Our analysis suggests that CF-SRT is also preferable to observation. Functional (111)In-octreotide single-photon emission computed tomographic scintigraphy provides a useful technique for the assessment of tumor control that complements serial posttreatment magnetic resonance imaging in patients with ONSMs.

A new approach to an old problem

A patient with progressive visual loss was found to have an optic nerve sheath meningioma. The patient was treated with stereotactic radiotherapy, a computer-guided stereotactic technique that minimizes the risk of radiation-induced optic neuropathy. Six months after treatment, the patient was doing well and showed no signs of radiation-induced optic neuropathy.

Optic nerve sheath meningiomas. Role of MR imaging

Optic nerve meningiomas usually are seen in middle-aged and elderly women, and present as a slowly progressing axial proptosis and loss of vision. CT and MR imaging are the most valuable diagnostic tools to evaluate these tumors. This article reviews the MR imaging and CT characteristics of optic nerve sheath meningiomas and discusses features that may distinguish optic nerve sheath meningiomas from simulating lesions.