Radiographic analysis of fatty infiltration of the extraocular muscles in thyroid eye disease.

PURPOSE: Fatty infiltration of the extraocular muscles has been described radiographically in patients with thyroid eye disease (TED), yet it has not been studied on a large scale nor quantified. Our purpose was to define and characterize this entity in patients with TED. METHODS: An IRB-approved cross-sectional retrospective review of medical records identified patients with a clinical diagnosis of TED and at least one CT of the orbits. A 2:1 age and sex-matched control population consisted of patients without a history nor radiographic evidence of orbital disease or systemic thyroid abnormality. The presence of fatty infiltration in each extraocular rectus muscle was defined using Hounsfield units (HU). Laterality, muscles involved, and pattern of fatty infiltration were also evaluated. Student's t-tests, Chi-square, and Fisher's exact tests were used to compare TED and control groups. RESULTS: The study population consisted of 252 patients with TED and 504 age and sex-matched controls. Fatty infiltration was significantly more prevalent in TED patients (36/252, 14.3%) compared to controls (11/504, 2.2%) (p < .001). The mean density of fat infiltration was significantly lower in TED patients (-40.4 HU) than controls (-34.8 HU) (p = .048). In TED patients, the frequency of muscle involvement was inferior rectus (61.8%), lateral rectus (19.7%), superior rectus (11.8%) and medial rectus (6.6%), which was not significantly different than controls (p > .05). Most muscles (88.2%) in the TED group exhibited a heterogeneous pattern of infiltration, which did not differ from controls (p = .34). CONCLUSIONS: This study characterizes fatty infiltration of the extraocular muscles in patients with TED.

Isolated orbital amyloidosis causing internal and external ophthalmoplegia.

Amyloid is a protein precursor known to deposit in ocular tissue. Although its presentation is protean, it is rarely seen in the orbit. We report the case of an 85-year-old woman with primary orbital amyloidosis causing internal and external ophthalmoplegia. Strabismus surgery with muscle biopsy alleviated her symptoms and assisted with solving the diagnostic challenge.

Periocular breast carcinoma metastases: correlation of clinical, radiologic and histopathologic features.

IMPORTANCE: To describe presenting patterns of breast cancer metastases to the orbit and eyelids. BACKGROUND: To provide clinical, radiographic and pathologic correlations of breast metastases to the orbit or eyelids and evaluate radiographic volumetric orbital changes. DESIGN: Retrospective review in an academic centre. PARTICIPANTS: Ten female patients with periocular metastatic breast carcinoma who were seen at the Massachusetts Eye and Ear Infirmary Oculoplastics Clinic. METHODS: Retrospective review of patient records, imaging and pathology findings. MAIN OUTCOME MEASURES: Presenting clinical characteristics, radiographic findings and histopathological features were assessed and correlated to discover distinctive presenting patterns. Volumetric measurements of the tumours and orbital soft tissue structures were made on magnetic resonance imaging studies. RESULTS: The breast cancer metastases included eleven orbital lesions and one eyelid lesion. Two distinct clinical presentations were observed. The first consisted of seven patients who had either enophthalmos or euphthalmos, a radiographically indistinct intraconal lesion and a histologically classic invasive lobular breast carcinoma with a prominent fibrotic stroma. The second group consisted of two proptotic patients with discrete mass lesions on imaging and an atypical invasive lobular breast carcinoma pathological subtype (pleomorphic or alveolar). One patient had diffusely indurated eyelid fullness. Volumetric analyses demonstrated variable tumour sizes with an inconsistent impact on the orbital volume and fat. CONCLUSIONS AND RELEVANCE: This correlative study provides the clinical-radiographic-histopathologic basis for separating two overarching phenotypic presentations of metastatic breast carcinoma to the orbit. Previously postulated mechanisms for the distinctive finding of tumour-induced enophthalmos are re-examined in the light of the foregoing conclusions.

Spontaneous Resorption of a Penetrating Orbital Bone Fracture Fragment.

The authors describe a 20-year-old man who sustained multiple facial fractures in a high-speed motor vehicle crash, including a bone fragment from a skull base fracture that penetrated the orbital soft tissues superomedially. Serial CT scans documented spontaneous resorption over a 6-month period. While it is known that autologous bone grafts used in craniofacial reconstruction exhibit variable amounts of bone resorption, the complete resorption of an intraorbital fracture fragment has not been documented in the literature. His clinical care and the report of his case were undertaken in a fashion in accordance with the principles of the Health Insurance Portability and Accountability Act regulations.

Papillary thyroid carcinoma nodal surgery directed by a preoperative radiographic map utilizing CT scan and ultrasound in all primary and reoperative patients.

BACKGROUND: To study the diagnostic accuracy of physical examination (PE), ultrasonography (US), contrastenhanced computed tomography (CT) and in preoperative detection of macroscopic nodal metastasis in primary/recurrent papillary thyroid carcinoma (PTC) patients to determine if the routine addition of CT would be beneficial in accurate preoperative lymph-node surgery planning. METHODS: In a tertiary center prospective study, 162 PTC patients underwent preoperative lymph-node evaluation by PE, US, and CT. Sensitivity, specificity, positive/negative predictive value (PPV/NPV) of each nodal detection technique were calculated in central/lateral cervical compartments. The gold standard for diagnostic-accuracy was surgical pathology. RESULTS: In patients undergoing primary (Group I)/revision (Group II) surgical treatment for PTC, combined US/CT yielded significantly higher sensitivity for macroscopic lymph-node detection in both lateral and central neck, most marked in Group I-central compartment. CONCLUSIONS: Combined preoperative US/CT provides reliable, objective, preoperative macroscopic nodal metastasis map to design rational nodal surgery in primary/revision PTC patients.

Medialization of the lamina papyracea after endoscopic ethmoidectomy: comparison of preprocedure and postprocedure computed tomographic scans.

OBJECTIVE: The purpose of this article is to report computed tomography demonstration of medial bowing of the lamina papyracea in 5 patients after internal ethmoidectomy. METHODS: We identified 5 patients who had apparent medial bowing of the lamina papyracea after functional endoscopic sinus surgery (FESS) and who had preoperative scans available. Preoperative and postoperative scans were reviewed using a 3-dimensional workstation to ensure similar angulation of the slices before measurement. Measurements of the interorbital distance and also the position of the posterior margin of the globe relative to a line connecting the lateral orbital walls were performed. RESULTS: Each of the patients demonstrated a decrease in the interorbital distance on the postoperative scan. Measurement of globe position showed that 9 of the 10 globes lay in a more posterior position within the orbit on postoperative examination. CONCLUSIONS: Medial bowing of the lamina papyracea may occur as a result of FESS and may lead to relative enophthalmos in comparison. The incidence of this phenomenon is unknown because most patients are not reimaged after FESS.

Cross-sectional imaging of the thyroid gland.

Directed imaging is useful in assessing the thyroid gland. Nuclear scintigraphy reveals functional information about the thyroid gland, while cross-sectional imaging, including ultrasound, CT, and MR imaging provide important adjunctive anatomic information about the thyroid as well as about related structures in the neck, including the presence or absence of cervical and mediastinal lymphadenopathy, or extension of thyroid disease into adjacent soft tissues or the mediastinum. This article reviews the anatomy and physiology of the thyroid gland and addresses issues related to diseases affecting the thyroid gland, with an emphasis on neoplasms and the role of cross-sectional MR and CT imaging in the assessment of thyroid neoplasia.