CYSTIC AND VASCULAR LESIONS

CYSTIC AND VASCULAR LESIONS
Cavernous Hemangioma
Cavernous hemangiomas are well-encapsulated tumors found behind the eye within the boundaries of the rectus muscles (intraconal) and composed of very large vascular channels. The vessel walls contain smooth muscles and there is fibrous tissue in the trabeculae that separates the vessels. Cavernous hemangiomas produce slowly progressive proptosis and indentation of the posterior portion of the globe (Figure 10-47). Radiologic studies show a rounded mass with smooth contours (Figure 10-48). Echography shows a lesion with characteristic high internal reflectivity (highly echogenic). One would prefer not to aspirate this lesion because of the risk of orbital hemorrhage. However, at least four fine needle biopsies of cavernous hemangiomas have been performed without complications. [3, 8, 69] In every one of these cases, the fine needle revealed only the blood harbored in the large cavernous spaces (Figure 10-49).

Hemangiopericytoma
Hemangiopericytoma is a highly vascular tumor, presumably arising from pericytes, with a characteristic staghorn appearance of vessels. It occurs at a median age of 42, with twice the frequency in men as woman. [70] The presenting findings of the tumor include proptosis, palpable mass, pain, and diplopia of about three years’ duration. Fine needle aspiration reveals spindle and oval cells with occasional branched vessels (Figure 10-50).

Mucocele
Mucoceles are tumors composed of mucous debris and which are caused by obstruction of the ostia of the sinuses. Mucus is secreted by entrapped epithelium and enlarges the sinuses. The frontal sinus is the most common site of origin for orbital mucoceles, but they may also occur in the ethmoid, sphenoid, and maxillary sinuses. [71, 72, 73, 74, 75] Radiologically, the mucocele is recognizable as a lucent mass with smooth scalloped borders expanding the sinus and destroying sinus septae around the orbit. Fine needle aspiration reveals a large amount of mucoid material with occasional vacuolted macrophages (mucophages) (Figure 10-51). In general, fine needle aspiration is done when an underlying neoplasm is suspected.

References

69. Meyer E, et al. Fine-needle aspiration of orbital lesions. Ann Ophthalmol. 1983 Jul;15(7):635-8.
70. Croxatto JO, et al. Hemangiopericytoma of the orbit: a clinicopathologic study of 30 cases. Hum Pathol. 1982 Mar;13(3):210-8.
71. Montgomery WW. MUCOCELE OF THE MAXILLARY SINUS CAUSING ENOPHTHALMOS. Eye Ear Nose Throat Mon. 1964 May;43:41-4.
72. Alberti PW, et al. Fronto-ethmoidal mucocoele as a cause of unilateral proptosis. Br J Ophthalmol. 1968 Nov;52(11):833-8.
73. Guerry R, Smith J, Paranasal sinus carcinoma causing orbital muscocele. Am J Opthalmol 1975;80:943-946.
74. Johnson LN, et al. Sphenoid sinus mucocele (anterior clinoid variant) mimicking diabetic ophthalmoplegia and retrobulbar neuritis. Am J Ophthalmol. 1986 Jul 15;102(1):111-5.
75. Stanton MB. Sphenoid sinus mucocele. Am J Ophthalmol. 1970 Dec;70(6):991-4.

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