The differential diagnosis of orbital calcification as detected on computed tomographic scans

Optic disc drusen: Dystrophic calcification, a potential target for treatment

Optic disc drusen (ODD) are calcified, acellular bodies, seen in the optic nerve head of up to 2% of the population. Although seldomly affecting visual acuity, visual field defects are common, and severe, ischemic complications causing irreversible vision loss are known to occur. Different treatment strategies for ODD have been explored, but so far without success. This review focuses on the unique, calcified property of ODD, describing what we know about ODD pathogenesis and previously tried treatment strategies. In this context, we discuss current knowledge about calcium and pathological calcifications, including intracranial and ocular calcifications. We also explore some of the obstacles that must be addressed to develop a therapy centred on the concept of calcification, should calcification be identified as a pathogenic factor contributing to vision loss.

An orbital calcific cyst following exenteration

A 77-year-old Asian female with a history of left orbit exenteration and lid-sparing reconstruction for recurrent sebaceous carcinoma presented with fluid-like sensation of the left orbit. Magnetic resonance imaging (MRI) demonstrated bright T2 signal and a cyst-like cavity within the exenterated orbit. Decision was made to proceed with surgical exploration and excision. A calcified, bone-like cavity was encountered intraoperatively and removed. Histopathology revealed dense fibrous connective tissue with areas of calcification without osseous metaplasia, suggestive of retained blood in the orbit that underwent dystrophic calcification. This case report illustrates a rare occurrence of a bone-like calcific cyst following exenteration.

Enlarging Orbital Rim Mass Due to Old Pencil Injury

A 54-year-old female noticed a 2-month history of an enlarging left inferomedial orbital rim mass. The patient remembered a pencil injury at approximately 7 years of age. Her complete ophthalmic examination was otherwise unremarkable. She underwent CT orbital imaging, demonstrating a centrally hyperdense lesion along the left inferomedial orbital rim. There was no involvement of the nasolacrimal duct system. The patient underwent an excisional biopsy. The pathology disclosed noncaseating granulomatous inflammation to particulate black material consistent with graphite.

Lacrimal gland pleomorphic adenoma and malignant epithelial tumours: clinical and imaging differences

AIMS

To investigate the clinical and imaging features of primary and recurrent lacrimal gland pleomorphic adenoma (LGPA), as well as lacrimal gland malignant epithelial tumours (LGMET).

METHODS

Retrospective comparative case series from September 2000 to September 2016 in a single tertiary institution. Medical records of cases with histopathologically proven primary LGPA (PLGPA), recurrent LGPA (RLGPA) and LGMET were reviewed.

RESULTS

Sixty-four patients with LGPA (55 primary and nine recurrent) and 36 patients with LGMET underwent surgical excision in the study period. There was no significant difference in terms of age, gender or laterality. In terms of symptom duration, that of LGMET (7.1 months) was significantly shorter than PLGPA (23.9 months), which in turn was significantly shorter than RLGPA (127.1 months). Proptosis was the most common presenting symptom among all three groups. On CT, LGMET and RLGPA were significantly more likely to have ill-defined margins (p<0.001) and be heterogeneous (p<0.001) than PLGPA. RLGPAs (56%) were significantly more likely to have calcification than LGMET (34%), which in turn was more likely to have calcification than PLGPA (13%); LGMET (40%) and RLGPA (33%) were significantly more likely to have bony invasion than PLGPA (2.2%). On MRI, LGMETs (55%) were significantly more likely to have a tail or wedge sign indicating infiltration into the posterior orbit than PLGPA (0%) or RLGPA (0%).

CONCLUSION

Our study adds important information regarding differentiating clinical and radiological features between malignant and benign epithelial lacrimal gland tumours that would aid in their management.

Orbital melanoma with calcification: A diagnostic dilemma

Primary orbital melanoma is rare and has varied initial presentation. A 28-year-old female presented with proptosis and decreased vision in the left eye. Computed tomography scan showed an orbital mass with contrast enhancement and calcification around the optic nerve leading to a diagnosis of meningioma. The patient chose to be on observation. Loss of vision with an increase in proptosis was seen at 6 months follow-up. On surgical exploration, a well-defined pigmented mass was seen encasing the optic nerve. Histopathological analysis revealed a malignant melanoma. Metastatic workup was negative. Left eye lid sparing exenteration was done. A high index of suspicion is necessary in a rapidly growing suspected optic nerve sheath meningioma and a differential diagnosis including orbital melanoma be considered.

A new cause of lacrimal gland calcification: Retained metallic foreign bodies

A 49-year-old male presented with a 4 month history of dysaesthesia in the left periorbital region. A CT scan showed a lacrimal gland mass with areas of dense calcification. Biopsies of the left lacrimal gland revealed a silver material with associated chronic granulomatous inflammation and secondary calcification. The histological specimen was sent for X-ray microanalysis. This confirmed the silver material to be aluminium. The metal fragments were subsequently discovered to be from a car aerial, which caused an orbital impaling injury 20 years prior to presentation. This is the first reported case of lacrimal gland calcification secondary to chronic metal foreign body exposure. The case is presented alongside literature reviews of lacrimal gland calcification and associated radiological findings.

Clinical significance of trochlear calcifications in the orbit

BACKGROUND AND PURPOSE

Trochlear calcification is frequently seen on CT scans that include the orbits, but prior studies linking this finding to diabetes mellitus were based on selected populations by using relatively thick sections. We assessed the relationship between trochlear calcification and diabetes mellitus and other chronic medical conditions in an unrestricted population by using thin-section CT.

MATERIALS AND METHODS

Noncontrast head CT studies performed consecutively on 1000 patients between January and February 2011 were retrospectively reviewed for the presence of trochlear calcifications. Axial 1.25-mm-thick images acquired by 64-detector row CT were reviewed. Medical records were reviewed for chronic medical conditions, including diabetes mellitus, chronic kidney disease, alcoholism, autoimmune conditions, endocrine disorders, serum calcium and alkaline phosphatase levels, and HIV status. Motion-limited studies and patients with limited clinical data were excluded. Statistical analyses were performed by using the Fisher exact test.

RESULTS

Thirty-two patients were excluded from analysis. Of the remaining 968 patients, 128 had trochlear calcification (13%). No significant association was observed between diabetes mellitus and trochlear calcifications in patients of any age (P = .40). There was no significant correlation between trochlear calcifications and chronic kidney disease, alcoholism, endocrine disorders, or HIV infection. Statistically significant associations among trochlear calcification, autoimmune conditions, and elevated alkaline phosphatase levels were observed (P < .0001 and P < .0001, respectively).

CONCLUSIONS

On the basis of a large unrestricted population with thin-section CT imaging of the orbit, no significant association was observed between trochlear calcifications and diabetes mellitus. A statistically significant association was observed between trochlear calcification and autoimmune disease and elevated alkaline phosphatase levels.

Trochlear calcification: a common entity

PURPOSE

This study aims to quantify the prevalence of trochlear calcification.

METHODS

A retrospective case review was performed on orbital CT scans ordered at Wills Eye Emergency room and Jefferson Hospital for Neuroscience for patients from June 2009 through September of 2009.

RESULTS

In our series, we examined 132 scans, 61% (81/132) men, 39% (51/132) women, ranging in age from 10-83. We found a 13% (17/132) prevalence of calcification of the trochlea, 53% (9/17) unilateral and 47% (8/17) bilateral. Forty-one percent (7/17) were female, 59% male (10/17). Age (19-83) was not a factor in the presence of trochlear calcification. The calcification either came straight off of the bone or was free-floating in the trochlea.

CONCLUSIONS

Our study establishes that calcification of the trochlea is common in the general population with a prevalence of 13%. Calcification of the trochlea should be considered in the differential diagnosis of hyperintense densities in the superomedial orbit, especially in cases of trauma where it can be confused with a foreign body.

Incidence of calcification of the trochlear apparatus in the orbit

Purpose

To quantify the incidence of asymptomatic incidental trochlear calcifications and to describe their clinical features.

Methods

We retrospectively reviewed orbital computed tomography (CT) scans of 216 patients to identify the presence of trochlear calcifications. We analyzed the prevalence, age distribution, and gender preponderance of trochlear calcifications. We also examined age-specific prevalence rates for trochlear calcifications, as well as their relationship to systemic disease.

Results

The mean age of patients was 26.8 years. Trochlear calcifications were observed in 35 (16%) of the 216 patients, and 18 of the 35 patients had bilateral calcifications. The rate of trochlear calcification was higher in males; 32 (20.9%) of 153 male patients had trochlear calcifications, compared with 3 (4.8%) of 63 female patients. Age, hypertension, diabetes mellitus, and thyroid disease were not significantly associated with the incidence of trochlear calcifications.

Conclusions

Incidental asymptomatic orbital calcification is more commonly observed on CT images than we expected and occurs predominantly in male patients. Understanding this to be a relatively common, benign finding may help us to rule out foreign bodies and other pathologic conditions.

Diagnostic tests in neuro-ophthalmology

This article reviews the diagnostic testing used in the evaluation of several common neuro-ophthalmologic entities including optic nerve disease, pseudotumor cerebri, anisocoria, ptosis, and ocular motor palsies. Emphasis is placed on these bedside tests that help to establish the diagnosis of these common clinical problems. The utility of the cocaine and Tensilon (edrophonium chloride) tests as well as the role of neuroimaging in these conditions are reviewed.