Onychocytic matricoma presenting as pachymelanonychia longitudinal. A new entity (report of five cases).

Among the tumors of the epidermal appendages, only rare tumors have been proved as differentiating in the direction of the nail. Beside onychomatricoma, we report a new matrical tumor of the nail: onychocytic matricoma (acanthoma of the nail matrix producing onychocytes). The main differential diagnosis of onychocytic matricoma is seborrheic keratosis. However, if attention is paid to the nature of the different layers of the tumor and the peculiar microanatomy of the nail matrix, the differentiation is not difficult. Onychocytic matricoma is a localized (monodactylous) longitudinal melanonychia which is slightly raised. The term pachymelanonychia is used to define the 2 clinical features of the tumor. Pachyonychia indicate a localized thickening of the nail plate, and melanonychia indicate its longitudinal pigmented band. Onychocytic matricoma is composed of a basal compartment with a varying admixture of prekeratogenous cells and keratogenous cells. Endokeratinization originating in the deep portion of the tumor and nests of prekeratogenous and keratogenous cells in concentric arrangement are a characteristic feature. Three major patterns can be identified as follows: acanthotic, papillomatous, keratogenous type with retarded maturation. Given the peculiar thickening of the nail plate observed both in pigmented onychomatricoma and onychocytic matricoma, the term pachymelanonychia longitudinal could be proposed to specify clinically these 2 lesions, which the clinician sometimes mistakes for melanoma.

[Data quality of cancer registration by Adicap codes, used by French pathologists from Paca, 2005-2006]. / Evaluation de la qualité du recueil des codes Adicap de tumeurs invasives et in situ par le Crisap de Paca Est, 2005-2006.

AIM: To assess the reliability of systematic and exhaustive cancer Adicap code registration by French pathology laboratories within the Crisap of Paca East network. METHODS: The Adicap code includes tumour site, histology and pathology technique. A quality control programme was applied to malignant and in situ tumours with an Adicap code to assess data quality, correct errors and supply missing data, based on IARC recommendations. RESULTS: In 2005 and 2006, 45,980 pathology examinations were entered in the Crisap of Paca East database. There was at least one Adicap code per examination, patients, surgeons and pathologists were identified and date of diagnosis was completed, as recommended by the HAS-Afaqap 2005 French pathologist professional quality control. Discrepancies between histopathology tissue and tumour site were found in 0.32% of cases (n=147), between age and histopathology in 0.04% of cases (n=19), and between genital tumour and sex in 0.01% of cases (n=3). In 2006, within 9535 subjects, dates of birth and postcodes of residence were missing, respectively, in 0.39% (n=37) and 22.46% (n=2142) of cases. CONCLUSION: Data quality for the Adicap code database may be considered satisfactory. Extended to Paca in 2007, Crisap Paca database can now be exploited for Paca regional cancer control strategy.