When basal cell carcinomas became giant: an Italian multicenter study.

BACKGROUND: Giant basal cell carcinoma (GBCC) is a basal cell carcinoma (BCC) enlarged in a diameter more than 5 cm. Since GBCCs are a highly infrequent entity and the occurrence rate is approximately 0.5-1% out of all BCC types, only anecdotal cases are reported, and causes and characteristics inducing development of this tumor are not defined. OBJECTIVES: Evaluate causative factors and clinico-histological characteristics of GBCCs. METHODS: The study is a 6-month, hospital-based case series study performed in 12 Italian dermatologic centers. RESULTS: A total of 59 cases and 458 control BCCs were collected. No significant differences existed between the two groups if we take into account social or cultural factors. The average duration of GBCCs is considerably longer than controls. GBCCs are located on unexposed areas while BCCs are on areas not usually covered by clothes. Superficial histological subtype was more frequent in the BCCs group, while infiltrative in GBCCs. GBCCs showed significantly higher local invasiveness, and greater metastatic capacity. More than half of GBCCs had been previously treated with one or more treatments. CONCLUSIONS: Patients with GBCCs appear to belong to two categories: (i) those who present with GBCC due to delay in accessing medical attention, and (ii) those who have BCCs previously treated with inappropriate strategies. Only very few cases can be carried out with intrinsic biological features of tumor aggressiveness. Social and cultural conditions do not appear to be involved in the development of GBCCS. These observations may help clinicians in selecting correct therapeutic strategies in the treatment of BCCs, which give rise to GBCC.

Negative pigment network: an additional dermoscopic feature for the diagnosis of melanoma.

BACKGROUND: The negative pigment network (NPN) is seen as a negative of the pigmented network and it is purported to be a melanoma-specific structure. OBJECTIVES: We sought to assess the frequency, sensitivity, specificity, and odds ratios (ORs) of NPN between melanoma cases and a group of control lesions. METHODS: Digitalized images of skin lesions from 679 patients with histopathological diagnosis of dermatofibroma (115), melanocytic nevus (220), Spitz nevus (139), and melanoma (205) were retrospectively collected and blindly evaluated to assess the presence/absence of NPN. RESULTS: The frequency of occurrence of NPN was higher in the melanoma group (34.6%) than in Spitz nevus (28.8%), melanocytic nevus (18.2%), and dermatofibroma (11.3%) groups. An OR of 1.8 emerged for the diagnosis of melanoma in the presence of NPN as compared with nonmelanoma diagnosis. Conversely, for melanocytic nevi and dermatofibromas the OR was very low (0.5 and 0.3, respectively). For Spitz nevi the OR of 1.1 was not statistically significant. When comparing melanoma with dermatofibroma, melanocytic nevus, and Spitz nevus, we observed a significantly higher frequency of multicomponent pattern (68.1%), asymmetric pigmentation (92.9%), irregularly distributed NPN (87.3%), and peripheral location of NPN (66.2%) in melanomas. LIMITATIONS: Further studies can provide the precise dermoscopic-histopathologic correlation of NPN in melanoma and other lesions. CONCLUSIONS: The overall morphologic pattern of NPN, such as the irregular distribution and the peripheral location of NPN, along with the multicomponent pattern and the asymmetric pigmentation could be used as additional features in distinguishing melanoma from Spitz nevus and other benign lesions.