An extremely rare case, complex differential diagnosis and the importance of specialist ophthalmological expertise.

In ophthalmic clinical practice, cases that prompt specialists to reconsider an initial diagnosis and seek an atypical explanation for a pathological process are uncommon. One such case involved a gouty tophus of the eyelid skin in a 6-year-old child, diagnosed by specialists at the  SI “V. P. Filatov Institute of Eye Diseases and Tissue Therapy of the NAMS of Ukraine”.

This case is unique for several reasons. Gout is an extremely uncommon condition in childhood, while gouty tophi involving the eyelid are an exceptionally rare pathology. Only isolated cases of this type of localisation have been reported in the available international literature, with the vast majority of patients being adult men.

WHEN EXTERNAL SIGNS ARE MISLEADING

The pathological lesion on the child's eyelid clinically resembled a dermoid cyst, which was consistent with the initial clinical presentation.

It is precisely in such situations that the expertise of a specialist ophthalmology centre becomes particularly important: rare conditions can masquerade as much more common pathological processes.

In this case, the specialists at the Filatov Institute were able to look beyond the initial clinical hypothesis, analyse the characteristics of the pathological lesion in detail and determine its true nature.

The definitive answer came from morphological diagnosis — examination of the tissue sample revealed the characteristic features of a gouty tophus.

WHY THIS CASE IS UNUSUAL

Gouty tophi are deposits of monosodium urate crystals that typically form in joints and periarticular tissues. Eyelid involvement is exceptionally rare.

In most cases described in the international literature, tophi were localised in the corners of the eye, and less frequently in the central parts of the eyelids. Their sizes ranged from a few millimetres to over a centimetre. In some patients, multiple tophi even caused functional impairments, in particular upper eyelid ptosis.

The distinctive feature of the present case is not only the unusual location of the lesion, but, above all, the patient's age — 6 years.

The combination of childhood age, the absence of typical clinical manifestations of gout, and localisation of the pathological process within the eyelid tissues significantly complicated the diagnostic process.

MORPHOLOGICAL DIAGNOSIS — THE KEY TO THE CORRECT ANSWER

The diagnosis of gouty tophi has its own specific features. To preserve sodium monourate crystals during histological examination, correct fixation and subsequent processing of the specimen are of paramount importance.

If there is no information suggesting possible gout, standard tissue fixation in 10% neutral buffered formalin may alter the appearance of the crystals. In such cases, the expertise of the pathologist and the use of specialised examination methods are of fundamental importance for establishing the correct diagnosis.

Thus, it was precisely the comprehensive approach — clinical assessment, differential diagnosis, and in-depth morphological examination — that enabled specialists at the Filatov Institute to identify a rare pathology that could clinically resemble an ordinary benign eyelid lesion.

A RARE CASE OF SIGNIFICANT PRACTICAL IMPORTANCE

This clinical case once again demonstrates how important it is, in complex and atypical situations, to consult specialist ophthalmology centres where a full range of diagnostic tests can be carried out.

The Filatov Institute is not only a center for the treatment of common ophthalmic diseases, but also a place where rare pathology can be diagnosed — pathology that may remain unrecognised because of its rarity and atypical clinical presentation.

The presented case of a gouty tophus of the eyelid in a 6-year-old child is a striking example of how clinical experience, attentiveness to atypical manifestations of the disease and the capabilities of specialised morphological diagnostics help to find an answer even in the most complex cases.