Malignant Melanoma in Lagos, Nigeria: Elucidating Histopathologic Prognostic Factors.

BACKGROUND: Malignant melanoma (MM) is the most lethal of all cutaneous malignancies, accounting for about 79% of skin cancer related deaths. In blacks, it is associated with greater morbidity and mortality compared to Caucasians. Breslow thickness and ulceration status are two of the most important histopathologic prognostic factors in MM. No study on MM in Nigeria has however examined these factors. METHODS: Formalin-fixed paraffin-embedded (FFPE) tissue blocks and corresponding Haematoxylin and Eosin (H&E) stained slides of all confirmed cases of MM from January 2005 to December 2014 in the AMP Department of Lagos University Teaching Hospital (LUTH) were retrieved. RESULTS: Fifty-two MM cases were histologically diagnosed in LUTH during the study period which represented 1.0% of total solid malignancies. Forty-three of these occurred in the skin accounting for 19.7% of all skin malignancies and making MM the 3rd commonest skin malignancy after squamous cell carcinoma (SCC) and kaposi sarcoma (KS). Eighty eight percent (88%) of the tumour were in Clark's stage IV and V while 84% had Breslow thickness >4mm. Ulceration was present in 67%. The Clark's level and Breslow thickness were correlated with the ulceration status of the tumour. There is significant correlation between the Breslow thickness and ulceration with p-value < 0.05 while there is no significant association between the Clark's level and ulceration. CONCLUSION: MM constituted a significant proportion of skin malignancy in LUTH and majority of the cases present at an advanced stage. Breslow thickness and ulceration statuses of the tumour are important histopathologic parameters that should be reported in all MM biopsies.

CONTEXTE: Le mélanome malin (MM) est la plus meurtrière de toutes les affections malignes cutanées, représentant environ 79 % des décès liés au cancer de la peau. Chez les Noirs, il est associé à une plus grande morbidité et de mortalité plus élevées que chez les Caucasiens. L'épaisseur de Breslow et le statut d'ulcération sont deux des facteurs pronostiques histopathologiques les plus importants du MM. Aucune étude sur le MM au Nigeria n'a cependant examiné ces facteurs. MÉTHODES: Nous avons récupéré des blocs de tissus fixés au formol et incorporés en paraffine (FFPE) ainsi que les lames correspondantes colorées à l'hématoxyline et à l'éosine (H&E) de tous les cas confirmés de MM entre janvier 2005 et décembre 2014 dans le département AMP du Lagos University Teaching Hospital (LUTH). RÉSULTATS: Cinquante-deux cas de MM ont été diagnostiqués histologiquement au LUTH pendant la période d'étude, ce qui représente 1,0 % du total des tumeurs malignes solides. Quarantetrois de ces cas sont survenus dans la peau, ce qui représente 19,7% de toutes les tumeurs cutanées et fait du MM la troisième tumeur cutanée la plus fréquente après le carcinome épidermoïde (SCC) et le sarcome de Kaposi (KS). Quatre-vingt huit pour cent (88%) de la tumeur étaient au stade IV et V de Clark tandis que 84% avaient une épaisseur de Breslow e"4mm. Une ulcération était présente dans 67% des cas. Le niveau de Clark et l'épaisseur de Breslow étaient corrélés avec le statut d'ulcération de la tumeur. Il existe une corrélation significative entre l'épaisseur de Breslow et l'ulcération avec une valeur p < 0,05 alors qu'il n'y a pas d'association significative entre le niveau de Clark et l'ulcération. CONCLUSION: Le MM constitue une proportion significative des tumeurs cutanées malignes à l'hôpital LUTH et la majorité des cas sont à un stade avancé. L'épaisseur de Breslow et les statuts d'ulcération de la tumeur sont des paramètres histopathologiques importants qui devraient être rapportés dans toutes les biopsies de MM. Mots clés: Mélanome malin, épaisseur de Breslow, niveau de Clark, ulcération, facteurs pronostiques.

Unravelling the Diagnosis - The Role of Histopathology in Mycosis Fungoides.

Mycosis fungoides is an extra-nodal indolent non-Hodgkin lymphoma of T- cell origin that is characterized by skin involvement. The course of the disease is typically slowly progressive with non-specific clinical and histopathologic features which may evade diagnosis for years. Chemo-therapeutic agents to control the disease are effective if employed early, but the prognosis and therapy is dependent on the stage of the disease at presentation. We report a case of a 25-year old man with a clinical diagnosis of Tinea incognito and histologic features of non-specific dermatitis at first presentation. With poor hospital attendance and inconsistent therapy, his clinical features and histology reports over the next couple of years were consistent with psoriasis, then mycosis fungoides. He is currently stable on chemotherapeutic agents. With different histopathology results over a three- year span, it is possible that the patient had both diseases occurring separately. It is also possible that psoriasis was a harbinger of mycosis fungoides and the change in clinical presentation which necessitated repeated biopsies eventually revealed the picture.

Immunohistochemical Analysis of BRAF (V600E) Mutation and P16 Expression in Malignant Melanoma in Lagos, Nigeria: A 10-Year Retrospective Study.

BACKGROUND: In Blacks, malignant melanoma (MM) is associated with greater morbidity and mortality compared to Caucasians. MMs with BRAF V600E mutation as well as those with loss of p16 protein expression are associated with aggressive behavior and worse prognosis. OBJECTIVES: We determined BRAF (V600E) mutation status and loss of p16 expression in MM cases in Lagos, Nigeria, and correlated these with histopathologic parameters and patients' age. METHODS: Forty-five cases of MM received between January 2005 and December 2014 in the Anatomic and Molecular Pathology Department of Lagos University Teaching Hospital were subjected to immunohistochemical studies to determine BRAF V600E mutation and p16 protein expression. These included cutaneous (n=37), musosal (n=3), and ocular MM (n=2) as well as lymph node metastatases (n=3). RESULTS: BRAF (V600E) mutations were detected in 5/45 (11%) while 31/45 (69%) of the cases had loss of p16 expression. No statistically significant association was found between the BRAF (V600E) mutation, loss of p16 expression, and histologic parameters such as histologic variant, Clark level, Breslow thickness, and ulceration. CONCLUSION: BRAF (V600E) mutation was detected only in a small proportion of cases while loss of p16 expression occurred in most cases which also had high Clark level, high Breslow thickness, and ulceration.