Transformation of a naevus into a mixed pyogenic granuloma-naevus mimicking conjunctival melanoma

Conjunctival Pyogenic Granuloma Masquerading as Malignant Melanoma

Pyogenic granuloma is a common, benign, vascular growth that often appears as a rapidly growing mass on mucus membrane-lined surfaces such as the conjunctiva. Conjunctival pyogenic granulomas are common following trauma, burst chalazion or ill-fitting prosthesis. Also known as 'lobular capillary hemangiomas', these lesions typically appear bright red, fleshy and pedunculated. Treatment options include excision, topical steroid therapy and topical beta-blocker therapy. In this communication, the authors describe a rapidly enlarging, pedunculated black coloured conjunctival mass lesion in a 44-year-old woman, who had a recent history of chalazia. Given the location and the clinical appearance, a melanocytic tumour was suspected and the mass was excised. Histopathology and immunohistochemical studies confirmed the diagnosis to be consistent with that of a a necrotic pyogenic granuloma. Pigmented lesions of the conjunctiva, especially rapidly enlarging ones, need to be viewed with a high degree of suspicion to rule out malignant melanoma. Rarely though, benign lesions such as pyogenic granulomas that undergo necrosis may masquerade as conjunctival melanomas.

Transcriptional characterization of conjunctival melanoma identifies the cellular tumor microenvironment and prognostic gene signatures

This study characterizes the transcriptome and the cellular tumor microenvironment (TME) of conjunctival melanoma (CM) and identifies prognostically relevant biomarkers. 12 formalin-fixed and paraffin-embedded CM were analyzed by MACE RNA sequencing, including six cases each with good or poor clinical outcome, the latter being defined by local recurrence and/or systemic metastases. Eight healthy conjunctival specimens served as controls. The TME of CM, as determined by bioinformatic cell type enrichment analysis, was characterized by the enrichment of melanocytes, pericytes and especially various immune cell types, such as plasmacytoid dendritic cells, natural killer T cells, B cells and mast cells. Differentially expressed genes between CM and control were mainly involved in inhibition of apoptosis, proteolysis and response to growth factors. POU3F3, BIRC5 and 7 were among the top expressed genes associated with inhibition of apoptosis. 20 genes, among them CENPK, INHA, USP33, CASP3, SNORA73B, AAR2, SNRNP48 and GPN1, were identified as prognostically relevant factors reaching high classification accuracy (area under the curve: 1.0). The present study provides new insights into the TME and the transcriptional profile of CM and additionally identifies new prognostic biomarkers. These results add new diagnostic tools and may lead to new options of targeted therapy for CM.