Review of extraocular muscle biopsies and utility of biopsy in extraocular muscle enlargement

[Interdisciplinary Management of Orbital Diseases]

Diagnosis and therapy of orbital diseases is an interdisciplinary challenge, in which i.e. otorhinolaryngologists, ophthalmologists, radiologists, radiation therapists, maxillo-facial surgeons, endocrinologists, and pediatricians are involved. This review article describes frequent diseases which both, otolaryngologists and ophthalmologists are concerned with in interdisciplinary settings. In particular the inflammatory diseases of the orbit including orbital complications, autoimmunological diseases of the orbit including Grave´s orbitopathy, and primary and secondary tumors of the orbit are discussed. Beside describing the clinical characteristics and diagnostic steps the article focusses on the interdisciplinary therapy. The review is completed by the presentation of most important surgical approaches to the orbit, their indications and possible complications. The authors tried to highlight the relevant facts despite the shortness of the text.

The Immunoarchitecture of Human Extraocular Muscles

Purpose

The purpose of this study was to describe the immunoarchitecture of normal extraocular muscles (EOMs) in terms of presence, distribution, and organization of various immune cells.

Methods

We performed unilateral orbital exenterations in six fresh human cadavers from elderly patients, followed by dissection of the medial, lateral, superior and inferior rectus, superior and inferior oblique, and superior palpebral levator muscle in their entirety. We further cross sectioned each EOM in an anterior, central, and posterior third. After immunohistochemical staining for CD3, CD8, CD20, CD138, CD68, and podoplanin, quantitative analysis was performed.

Results

We found all EOMs (rectus, oblique, and levator muscles) to harbor both T- and B-lymphocytes, with a B-lymphocyte dominance and an absence of plasma cells. The highest prevalence of immune cells was seen in the muscle bellies, with, on average, 488 ± 63 CD3+ T-lymphocytes and 44 ± 110 CD20+ B-lymphocytes per mm2, and significant differences from the anterior (T-lymphocytes) and posterior (T- and B-lymphocytes) thirds. T- and B-lymphocytes were primarily organized in hotspots in the vicinity of blood vessels. In addition, a small resident population of macrophages scattered throughout the specimens was detected. No lymphatic vessels were found in any of the EOMs.

Conclusions

These findings can serve as a reference dataset in the assessment of EOM biopsies in the diagnostic process of inflammatory orbital and systemic disorders. Moreover, from a regenerative perspective, our results highlight the importance of taking into account the presence of a resident immune cell population when studying the host immune response on transplanted tissues or engineered constructs.

Diagnostic performance of MRI for the assessment of extraocular muscle invasion in malignant sinonasal tumors

PURPOSE

Preoperative assessment of extraocular muscle invasion is essential for therapeutic strategies and prognostic evaluation. The aim of this study was to assess the diagnostic accuracy of MRI for evaluation of extraocular muscle (EM) invasion by malignant sinonasal tumors.

MATERIALS AND METHODS

Consecutively, 76 patients of sinonasal malignant tumors with orbital invasion were included in the present study. Preoperative MRI imaging features were analyzed by two radiologists independently. The diagnostic performances of MR imaging features for detecting EM involvement were evaluated by comparing imaging findings to histopathology data.

RESULTS

A total of 31 extraocular muscles were involved by sinonasal malignant tumors in 22 patients, including 10 medial rectus muscles (32.2%), 10 inferior rectus muscles (32.2%), 9 superior oblique muscles (29.1%), and 2 external rectus muscles (6.5%). The EM involved by sinonasal malignant tumors usually showed relatively high signal intensity on T2-weighted images, indistinguishable from the tumor, nodular enlargement and abnormal enhancement (p = 0.001, < 0.001, < 0.001 and < 0.001, respectively). Using a combination of EM abnormal enhancement and indistinguishable from the tumor in multivariate logistic regression analysis, sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy for detecting orbital EM invasion by sinonasal tumors were 93.5, 85.2, 76.3, 96.3 and 88%, respectively.

CONCLUSION

MRI imaging features show high diagnostic performance for the diagnosis of extraocular muscle invasion by malignant sinonasal tumors.

Extraocular Muscle Biopsy: Surgical Technique and Indications

Extraocular muscle biopsy is a technique used for the histological diagnosis of several orbital diseases; it could bring valuable assistance to the diagnostic process. The purpose of this article is to review the indications, surgical technique, and complications of this biopsy.

Extraocular muscle biopsy is frequently used in tumoral pathology, however, in inflammatory diseases, it is only used when facing a poor reaction to the treatment or in case of chronicity. The surgical procedure must be precise and least traumatic, in order to avoid intra- and post-operative complications, but also to preserve the integrity and function of the muscle. This procedure remains non-standardized and not devoid of complications, hence the need for a careful evaluation of the benefit/risk ratio before considering it.

Role of muscle biopsy in diagnosis of extraocular muscles enlargement

PURPOSE

To study the role of muscle biopsy in patients with enlarged extraocular muscles.

METHODS

A retrospective review of 31 patients who underwent biopsy for extraocular muscle enlargement. Characteristics, including signs, symptoms, imaging findings, and histopathological assessment were examined.

RESULTS

Chronic inflammatory disorders represented the most common cause of the muscle enlargement followed by malignancy/metastasis. Multiple muscle involvement was more consistent with benign diseases, whereas single muscle involvement was more consistent with malignant causes. Positive predictive value of muscle biopsy was 0.52 for determining a specific cause of the muscle enlargement.

CONCLUSIONS

Muscle biopsy is the standard for diagnosis in patients with extraocular muscle enlargement. This diagnostic test should be performed in every case of non-resolving muscle enlargement, with a specific diagnosis being made in over half of cases.

Clinical and Radiological Features of Intramuscular Orbital Amyloidosis: A Case Series and Literature Review

PURPOSE

Orbital amyloidosis of the extraocular muscles (EOMs) is a rare condition, and its clinicoradiological features are not well elucidated. This study describes the characteristic clinical signs, MRI features, and potential treatment options.

METHODS

Retrospective multicenter case series and literature review of EOM amyloidosis.

RESULTS

Five cases were identified for inclusion. Common clinical findings were diplopia, ophthalmoplegia, and proptosis. Systemic amyloidosis was more likely to present with multiple muscle involvement, but no particular pattern was observed with localized disease. On MRI, amyloid deposition was characterized as a heterogeneous intramuscular mass with T2 hypointensity and post contrast enhancement. Management is dependent on the extent of disease and functional impairment; options include surgical debulking and radiation therapy.

CONCLUSION

EOM amyloidosis is uncommon. The combination of clinical and radiologic findings described in this study should lead to its clinical suspicion.

A rare case of intramuscular angioma involving the medial rectus muscle

Benign benign vascular tumors (e.g., hemangiomas) and malformations are commonly encountered lesions in all ages of life, especially in infancy and childhood. Hemangiomas are considered to be proliferative vascular lesions while malformations are defects of embryonal vascular morphogenesis. Less than 1% of hemangiomas within the body occur in skeletal muscle and of these approximately 15% have been reported to occur in the head and neck musculature (e.g. masseter, trapezius, sternocleidomastoid, mylohyoid, temporalis muscles) Intramuscular angioma (the preferred term for lesions formerly known as intramuscular hemangiomas by WHO Tumors of Soft Tissue and Bone Classification, 5th edition 2020) (IA) occurring in the extraocular muscles or palpebral muscles (orbicularis oculi) are extremely rare with only a few case reports in the English literature. To date, all the extraocular muscles have reportedly been involved. With the case reported herein, the medial rectus muscle appears to be the most common extraocular muscle involved.

Primary isolated amyloidosis in the extraocular muscle as a rare cause of ophthalmoplegia: A case report and literature review

Purpose

To report a case of external ophthalmoplegia due to an uncommon form of amyloidosis exclusively affecting the lateral rectus muscle, and to discuss the clinical manifestation, diagnostic challenges, and management pitfalls of isolated amyloidosis in the extraocular muscle.

Observations

A 64-year-old woman presented with diplopia in her left gaze lasting for six months. She had orthophoria in the primary position and abduction limitation in the left eye. Routine laboratory examinations were unremarkable. Orbital magnetic resonance imaging showed fusiform enlargement of the left lateral rectus muscle, without tendon involvement. Extraocular muscle biopsy was recommended to make a diagnosis, which revealed amyloid deposition in the lateral rectus muscle. A systemic work-up showed no evidence of systemic amyloidosis. Therefore, a diagnosis of primary isolated amyloidosis was made. Orthophoria in the primary position and diplopia in the lateral gaze persisted at the six-month follow-up.

Conclusions and importance

Atypical extraocular muscle enlargement should alert clinicians to the need for tissue biopsy to identify uncommon etiologies, such as amyloidosis. There are no pathognomonic or radiological features to distinguish localized from systemic amyloidosis. Therefore, if amyloidosis of the extraocular muscles is diagnosed, a systemic work-up is needed to rule out systemic amyloidosis, which is potentially life-threatening.

Orbital disease in neuro-ophthalmology

PURPOSE OF REVIEW

Orbital disease represents a diverse spectrum of pathology and can result in a variety of neuro-ophthalmic manifestations. The aim of this review is to provide updates on recent advances in our understanding of orbital disease secondary to thyroid eye disease, myositis, IgG4-related disease, sarcoidosis, granulomatosis with polyangiitis and various tumours.

RECENT FINDINGS

With regards to thyroid eye disease, there have been recent advances in the development of steroid-sparing therapies, new modalities for objectively monitoring disease activity and increased understanding of the role of environmental risk factors. There has been interest in characterizing the clinical course and underlying mechanism of optic nerve disease secondary to orbital disorders, which has led to advances in how we monitor for and prevent permanent vision loss. Increased knowledge of orbital tumour subtype histopathology and the development of novel classification systems has had prognostic value and aided medical decision-making.

SUMMARY

Orbital disease occurs secondary to a wide variety of diseases and can lead to neuro-ophthalmic manifestations with significant morbidity. Advances in our understanding of different subtypes of orbital disease have improved our ability to treat these potentially debilitating conditions.

Histopathologic Findings in Idiopathic Orbital Myositis

PURPOSE

To report the histologic and clinical features of idiopathic orbital myositis (IOM) patients who underwent extraocular muscle (EOM) biopsy over 20 years, to provide the first methodical reference to the expected histopathologic findings, and to discuss the histopathologic differences from common differential diagnoses.

DESIGN

Cohort study.

PARTICIPANTS

All patients with a diagnosis of IOM who underwent EOM biopsy from 2000 through 2019 were included. Patients who had a different final diagnosis were excluded.

METHODS

Tissue samples of EOM and medical records of all participants were reviewed.

MAIN OUTCOME MEASURES

Histopathologic features of muscle biopsy, including tissue morphologic features and cellular composition.

RESULTS

Thirteen patients met both inclusion and exclusion criteria, and their tissue samples were revisited. Nine patients showed histopathologic findings that suggested a conclusive diagnosis of IOM, and the study focused on them. The average age at presentation was 49 years, and 66.7% of patients were women. The most commonly biopsied EOM was the medial rectus (44.4%). The most common indications for biopsy were nonresolving orbital disease with inadequate response to corticosteroids (44.4%) or a high suspicion of malignancy because of known pre-existing systemic malignancy or the presence of an atypical orbital mass in addition to enlarged muscles (44.4%). The histopathologic findings that suggested a diagnosis of IOM were splaying of muscle fibers by inflammatory infiltrates (n = 9) and mild fibrosis (n = 8) in the endomysium or replacing muscle fibers, with no granulomas or vasculitis. The inflammatory infiltrates identified were of chronic inflammatory cells, consisting of lymphocytes (n = 9), plasma cells (n = 6), and histiocytes (n = 6). Other less commonly identified cells were eosinophils (n = 4), polymorphonuclears (n = 1), and giant cells (n = 1). Muscle fiber degeneration or regeneration was evident in 5 patients. Four patients from the initial cohort showed inconclusive histologic findings on revision and were reassigned as suspected IOM.

CONCLUSIONS

The histopathologic features of involved muscles in IOM resemble those seen in idiopathic orbital inflammation and differ from those seen in common differential diagnoses. Extraocular muscle biopsy should be strongly considered whenever the presentation of orbital myositis is not typical or when significant underlying conditions are a possibility.

Granulomatosis with polyangiitis presenting as recurrent, multifocal orbital myositis

A 43-year-old woman was referred with a 10 month history of persistent pain in the left orbit. Two years prior, she experienced similar pain in the right orbit. Magnetic resonance imaging (MRI) at the time revealed an enlarged right medial rectus muscle. She was diagnosed with idiopathic orbital myositis and was successfully treated with oral corticosteroids. A year later, she developed symptoms in the left orbit with similar imaging findings. For ten months, she remained on high dose corticosteroids for presumed left medial rectus myositis before presenting to our service. Computed tomography (CT) imaging after corticosteroid taper revealed enlarged left medial rectus and left lateral rectus muscles. Orbital biopsy established a diagnosis of granulomatosis with polyangiitis (GPA), for which she was successfully treated with rituximab. This case underscores the importance of not only proceeding with biopsy in atypical cases of orbital myositis but to also taper steroids prior to biopsy.

Choroidal Melanoma Metastatic to the Contralateral Medial Rectus After Orbital Exenteration

A 78-year-old Caucasian woman presented with pain in her right and only eye that was worse on abduction. Her history was significant for a choroidal melanoma affecting her left eye for which she underwent an orbital exenteration 12 years previously. Computed tomography and magnetic resonance imaging of the right orbit identified a mass lesion affecting the medial rectus, suspicious for metastatic melanoma. A histopathological diagnosis of metastatic melanoma was subsequently made following biopsy of the right medial rectus.

Extraocular muscle biopsy during surgery for strabismus of unknown etiology

Most cases of strabismus have a chronic and stable or known etiologic diagnosis prior to surgery. In some cases, however, surgery is undertaken to correct a stable ocular misalignment without a definitive etiology. We present 2 cases, one with euthyroid Graves' orbitopathy and the other with amyloid light-chain amyloidosis, in which extraocular muscle biopsy performed intraoperatively allowed histopathologic confirmation of a clinical diagnosis.

Clinicopathological Features and Outcomes in Lymphoma of Extraocular Muscles

PURPOSE

To describe the clinicopathological features and report the outcomes of treatment in lymphoma involving the extraocular muscles (EOM), the largest reported case-series.

METHODS

A retrospective case series of patients with lymphoma involving the EOM from a single tertiary referral orbital center, between March 1992 and March 2018. Patients with other histopathologic diagnoses or who did not have an EOM biopsy were excluded. The main outcome measures were histologic evaluation and clinical follow-up including tumor response, recurrence, and survival.

RESULTS

Twenty-five patients were included, 16 female; 9 male; median age 64.7 years (range 33.8-92.6 years). Unilateral involvement was present in 23 cases (92%). Lymphoma was found to be primary in 15 patients (60%), and any EOM could be affected by disease. Fourteen patients (56%) displayed impaired duction in the direction of the affected muscle. The commonest histologic type was extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue in 16 cases (64%) followed by follicular lymphoma in 3 cases (12%), diffuse large B-cell lymphoma in 2 cases (8%), gamma delta T-cell lymphoma in 2 cases (8%), small lymphocytic lymphom and lymphoplasmacytic lymphoma in 1 case each (4%). All 4 patients with high-grade lymphomas (diffuse large B-cell or T cell lymphoma) were found to have systemic disease. Patients were treated with combinations of radiotherapy, chemotherapy, or immunotherapy, with low toxicity. Two patients developed treatment-related complications. With a median follow-up of 26 months (range 3-108 months), there was only 1 recurrence, which was successfully salvaged with Rituximab, and no deaths due to lymphoma.

CONCLUSIONS

Lymphoma of the EOM is a rare tumor with good response to treatment, few treatment-related complications and low risk of recurrence or mortality.A retrospective review of 25 patients with lymphoma of the extraocular muscles demonstrates excellent prognosis with a high rate of local remission (96%), 2 treatment-related complications, one recurrence, and no disease-related deaths.