Gout is a group of diseases characterized by hyperuricemia that leads to deposition of urate crystals in many tissues of the body, including the joints, skin, bursae, periarticular ligaments, and kidneys.1 One distinctive pathological finding in patients with gout is the tophus, a deposition surrounded by inflammation.1 Tophi rarely involve the face. We found only 2 reports of a gouty tophus on the face, one on the upper eyelid near the lateral canthus2 and the other on the bridge of the nose.3 We present the clinical and histopathological findings in a patient with what, we believe, is only the second reported case of a gouty tophus adjacent to the eye.
A 44-year-old man was referred for evaluation of a painless mass near the lateral canthus of the right eye (Figure 1) that had been present and gradually enlarging for approximately 1 year. The lesion had not bled, and there had been no discharge. The patient had a history of gout and arthritis, and the joints of his feet and wrists were swollen. Visual acuity with correction was 20/20−2 OU. Intraocular pressure was 19/13 mmHg by applanation tonometry. Examination of the conjunctiva, cornea, anterior chamber, and pupils demonstrated no abnormalities. The yellow, dome-shaped subcutaneous mass was located about 4.0 mm lateral to the lateral canthus of the right eye. No acute inflammatory signs were visible adjacent to the mass. An excisional biopsy was performed, the specimen was fixed in buffered formalin, and the tissue was submitted for histopathological examination. The incision site healed without incident.
Clinical appearance of the mass located lateral to the lateral canthus of the right eye.
Gross pathological examination demonstrated a unilocular cystic-appearing mass measuring 6.0 × 5.0 × 4.0 mm and filled with a cheesy tan-white substance. Study by light microscopy revealed a pseudocyst containing amorphous, eosinophilic material with irregular, elongated spaces (Figure 2). One large concentration near the center of the pseudocyst contained a few spindle-shaped nuclei and fine corrugations, suggesting possible sites of crystalline deposits (Figure 3).Examination of this area with polarized light demonstrated parallel birefringent crystals. The lining of the cavity comprised histiocytes, fibroblasts, and rare foreign-body giant cells (Figure 2).Staining with alcoholic eosin Y and viewing with polarized light using the method devised by Shidham and Shidham4 confirmed the presence of urates in this formalin-fixed tissue sample (Figure 4).
A light microscopic view of the excised pseudocyst (hematoxylin-eosin, original magnification ×100). The cavity contains amorphous eosinophilic material.
A high-power view of a larger fragment of the pseudocyst's contents (hematoxylin-eosin, original magnification×370). Corrugated areas suggest the presence of fine needle-shaped material(arrows).
A section stained with alcoholic eosin Y and viewed under polarized light (hematoxylin–alcoholic eosin Y, original magnification ×40). This technique demonstrates abundant birefringent crystals in the interior of the pseudocyst. PL indicates pseudocyst lumen; PW, pseudocyst wall; CR, birefringent crystals.
There are 3 characteristic pathological findings in gout: acute synovitis with effusion from deposition of crystalline urates secondary to hyperuricemia, chronic arthritis after multiple acute episodes from deposition of urates in the synovial lining and on the articular surfaces, and gouty tophus from localized deposition of crystals in soft tissue and the resultant inflammation.1 Although any joint in the body is at risk, the great toe is involved in 90% of patients, and other joints in the foot, knee, or wrist are commonly affected. Tophi occur in connective tissue and most commonly involve the helix and antihelix of the ear, the bursae adjacent to the olecranon and the patella, and the ligaments surrounding the joints. The renal medulla or pyramids may also show gouty tophaceous deposits.
Ocular involvement in patients with gout may take many forms. Crystalline deposits have been identified in the conjunctiva, sclera, and cornea.5,6 Other ocular conditions associated with gout are scleritis, episcleritis, uveitis, asteroid hyalosis, increased intraocular pressure, and chronically hyperemic conjunctivae.7 However, after studying 69 patients with gout, Ferry et al7 concluded that gout had been overemphasized as a cause of uveitis.
True tophi are rare on the eye or face. Yourish's case report described a "conjunctival tophus associated with gout, " but no histopathological examination was performed.5 The crystals he described in and beneath the conjunctiva were identified as a urate salt by chemical reaction. Martinez-Cordero et al6 observed a scleral "tophus, " but no inflammation was described, and no histopathological study was recorded. These authors also confirmed the crystals as urates by chemical means. These 2 case reports offered convincing evidence for urate deposition in the sclera and/or conjunctiva in patients with gout, but we do not feel that they meet the strict definition of a tophus. A search of the PubMed database yielded only 2 reports documenting a gouty tophus on the face. One patient had a tophus on the upper eyelid near the lateral canthus2 and the other on the bridge of the nose.3 Histopathological examination confirmed both diagnoses. To the best of our knowledge, ours is only the second report of a gouty tophus on or adjacent to the eyelid.
If the surgeon suspects a gouty tophus, the specimen should be fixed in absolute alcohol rather than buffered formalin to assist the pathologist in identifying the crystalline deposits. The surgeon should also inform the pathologist of the presumed diagnosis so that aqueous reagents are avoided during processing of tissue.
Although most patients with tophi have had gout for many years, the presence of a tophus may be the initial sign of gout, allowing the ophthalmologist to participate in the diagnosis of this important and painful systemic disease. The finding of a lesion similar to the one we have described in a patient with gout should cause the ophthalmologist to consider a gouty tophus in the differential diagnosis of a soft tissue mass on the eyelid.
The authors have no relevant financial interest in this article.
This study was supported in part by Research to Prevent Blindness, Inc, and the St Giles Foundation, New York, NY.
Corresponding author: William R. Morris, MD, Department of Ophthalmology, University of Tennessee Health Science Center, 956 Court Ave, Room D-222, Memphis, TN 38163 (e-mail: email@example.com).
Morris WR, Fleming JC. Gouty Tophus at the Lateral Canthus. Arch Ophthalmol. 2003;121(8):1195-1197. doi:10.1001/archopht.121.8.1195