[Inflammatory juvenile conjunctival nevus (IJCN)].

Background: Pathologists may occasionally have difficulties in reliably assessing the dignity of tumour cells in histological sections, especially in nevi with junctional activity.

Patient History: This case history of a boy suffering from an inflammatory juvenile conjunctival nevus (IJCN) is reported with a follow-up period of 25 years. Seven years after first surgical treatment of a histologically proven nevus, a recurrent pigmented lesion within the former operation area aroused the suspicion of it being a malignant melanoma. Logically, a second excision was performed followed by cryotherapy with liquid nitrogen (spray freezing). The histological diagnosis performed by a pathologist resulted in a malignant melanoma. A second recurrent pigmented conjunctival tumour developed fourteen years later. This lesion again aroused another strong clinical suspicion of malignant transformation into a melanoma. However, the histological examination of the biopsy at this time only showed benign nevus cells and areas of conjunctival melanosis without atypia.

Discussion: Especially in young patients, IJCN must be regarded as an independent type of nevus, which might lead even experts in ophthalmic pathology to over-diagnose this lesion as a malignant melanoma. This could mean that the wrong therapeutic steps were taken with surgical procedures that cause unnecessary mutilation. A reappraisal of the former histological specimens of the first recurrent tumour by other pathologists came to the conclusion that the initial diagnosis of melanoma could not be maintained. Nevertheless, we also strongly recommend follow-up examinations at regular intervals in cases of IJCN since we are aware of the fact that melanocytic tumours of the conjunctiva behave unpredictably.