The spectrum of spitzoid tumours: A clinical study

This study explores the relationship between different types of spitzoid tumours, spindle cell naevus of Reed and spitzoid melanomas. Clinical and histopathological data were retrospectively reviewed from our hospital database in Cambridge from January 2006 to July 2009. Clinical images, where available, were recorded. Search headings from our pathology database included 'spitzoid tumours', 'Spitz naevi', 'atypical spitzoid tumours', spitzoid tumours of uncertain malignant potential ('STUMP'), 'spindle cell naevus of Reed' and 'spitzoid melanomas'. The total number of spitzoid tumours was 118 comprising Spitz naevi (72), atypical spitzoid tumours (30), spitzoid melanomas (eight), and other naevi with spitzoid features (eight). In total, 60% of Spitz naevi were diagnosed clinically and 50% reported a history of change with spitzoid melanoma, compared with 32% with Spitz naevi. In all, 60% of Spitz naevi and atypical spitzoid tumours were pigmented in contrast with spitzoid melanomas (83%). Variegated pigmentation was found in 20% of Spitz naevi and atypical spitzoid tumours, however, no spitzoid melanomas had mixed pigmentation. There were 30 atypical spitzoid tumours (9 M : 21 F); 16 occurred on the lower limbs, peaking in the 20-30-years age group. There were eight patients with spitzoid melanomas with a 7:1 F : M ratio, 50% of which were diagnosed clinically. Of the 34 spindle cell naevus of Reed (10 M : 24 F), 31 were misdiagnosed, most commonly as melanoma. Reed naevi peaked in the 30-40 year age group and on the upper limbs and lower limbs in the 20-30-years age group. In summary, age and sex appeared helpful in distinguishing benign from malignant spitzoid tumours, however history was less discriminatory. Spitzoid melanomas, most of which were pigmented occurred more commonly in females. Atypical spitzoid tumours were more common in females and pathologists favoured malignancy in this group beyond 20 years of age.