Perspective Conjunctival melanoma and melanosis: a reappraisal of terminology, classification and staging Bertil Damato MD PhD FRCOphth 1 and Sarah E Coupland MBBS PhD FRC Path 2 1 Ocular Oncology Service, Royal Liverpool University Hospital, and 2 Department of Pathology, School of Cancer Studies, University of Liverpool, Liverpool, UK ABSTRACT This paper aims to stimulate debate on the terminology, classification, grading and staging of conjunctival melanosis and melanoma.We audited our results with 76 invasive con- junctival melanomas. Staging according to the sixth edition of the Tumour Node Metastasis (TNM) system did not corre- late well with tumour extent and outcome. Approximately 50% of invasive melanomas were associated with ‘primary acquired melanosis with atypia’, a term which in our opinion underestimates the gravity of this disease. We also found deficiencies in the grading, terminology and classification of conjunctival melanocytic abnormalities. In summary, we suggest that the term ‘primary acquired melanosis’ be reserved for clinical diagnosis. Histologically, this abnormality can be categorized more precisely as either ‘hypermelanosis’ or ‘conjunctival melanocytic intraepithelial neoplasia (C-MIN)’. ‘Primary acquired melanosis without atypia’ can be termed more accurately as ‘C-MIN without atypia’. In view of the high risk of invasive melanoma, we suggest that ‘primary acquired melanosis with atypia’ be termed ‘C-MIN’ with atypia, with the more severe changes regarded as melanoma in situ.To improve objectivity in the reporting of C-MIN, we propose a scoring system based on horizontal and vertical spread and degree of severity of melanocytic atypia. We suggest that the TNM staging system for conjunctival melanoma be revised to: (i) include a Tis stage; (ii) take account of tumour size, quadrant and caruncular involve- ment; and (iii) improve staging of any local invasion beyond conjunctiva. Key words: conjunctival neoplasm, disease-specific mortal- ity, melanoma, ophthalmology, pathology. INTRODUCTION The terminology of conjunctival melanotic abnormalities is confusing. For example, the noun, ‘melanosis’, which refers to melanotic pigmentation visible to the naked eye, is used to encompass both melanin hyper-secretion and melanocytic proliferation. 1 Furthermore, there is disagreement as to whether melanocytic intraepithelial neoplasia with atypia is pre-cancerous or cancerous. 2,3 As a result, the same disease at a particular point in the spectrum of malignancy may be termed ‘primary acquired melanosis with atypia’ (PAM with atypia) by one pathologist and ‘melanoma in situ’ by another, possibly risking under-treatment or over-treatment. Classification of conjunctival melanocytic disorders is valuable to clinicians and histopathologists considering the differential diagnosis of a particular case. Various systems have been developed (see later text), but in our opinion, these all have limitations, such as including congenital ocular melanocytosis, which does not involve conjunctiva, being sub-conjunctival. 4 The histological grading of PAM with atypia is variably described using terms such as ‘mild’ and ‘severe’. 5 There is scope for a system that grades this conjunctival melanocy- tic intraepithelial neoplasia (C-MIN) more objectively and reproducibly. This would make it easier to detect progression when sequential biopsies are performed over a long period and would enhance communication between the pathologist and ophthalmologist. Such a scoring system would also facili- tate multicentre collaboration when evaluating treatment. Conjunctival melanomas are staged according to the Tumour Node Metastasis (TNM) system, developed by the American Joint Committee on Cancer and the Union Inter- national Contre Cancer. 6 The objectives of this system are to stage disease in a standardized fashion so as to enhance prognostication, treatment planning and multicentre studies. We feel that the sixth edition categorizes conjunctival mela- nomas into stages that do not correlate adequately with  Correspondence: Dr Bertil Damato, Ocular Oncology Service, Royal Liverpool University Hospital, Prescot Street, Liverpool L7 8XP, UK. Email: bertil@damato.co.uk Received 16 April 2008; accepted 3 October 2008. Clinical and Experimental Ophthalmology 2008; 36: 786–795 doi: 10.1111/j.1442-9071.2008.01888.x © 2008 The Authors Journal compilation © 2008 Royal Australian and New Zealand College of Ophthalmologists