title: Melanoma and satellite blue papule.
abstract: The colors that are seen in dermoscopy depend on the anatomic level of the skin at which the chromophores are seen. Blue color can be found in a variety of melanocytic and nonmelanocytic lesions. An 89-year-old man presented with a 3-year history of a slow-growing, hyperpigmented patch located on the distal third of the right arm. Dermoscopy showed an atypical network, irregularly distributed globules, pigmented internal streaks and a milky-red area. Based on these findings a diagnosis of slow-growing malignant melanoma was made. Simultaneously, a well-defined blue papule was seen on the proximal third of the same arm. Dermoscopy disclosed a homogeneous blue pattern. After clinical and dermoscopic correlation our differential diagnosis for this blue lesion included cutaneous melanoma metastasis, blue nevus and foreign body reaction. The patient recalled its onset 75 years ago after a grenade explosion. We also discuss the blue lesion appearance under reflectance confocal microscopy and high-definition optical coherence tomography. Histopathological examination after excision of the hyperpigmented patch and blue papule revealed a melanoma in situ and a foreign body reaction, respectively. The diagnostic evaluation of a blue lesion should always rely on the integration of all data, especially clinical and dermoscopic features. Other non-invasive techniques, like reflectance confocal microscopy and high-definition optical coherence tomography can also be important aids for its differential diagnosis.
authors.affiliation: Department of Dermatology, Hospital de Curry Cabral-Centro Hospitalar de Lisboa Central, Lisboa, Portugal.
authors.forename: André
authors.initials: A
authors.lastname: Oliveira
authors.affiliation: Department of Dermatology, Medical University of Graz, Graz, Austria.
authors.forename: Edith
authors.initials: E
authors.lastname: Arzberger
authors.affiliation: Department of Dermatology, Medical University of Graz, Graz, Austria.
authors.forename: Cesare
authors.initials: C
authors.lastname: Massone
authors.affiliation: Department of Dermatology, Medical University of Graz, Graz, Austria.
authors.forename: Iris
authors.initials: I
authors.lastname: Zalaudek
authors.affiliation: Department of Dermatology, Medical University of Graz, Graz, Austria.
authors.forename: Regina
authors.initials: R
authors.lastname: Fink-Puches
authors.affiliation: Department of Dermatology, Medical University of Graz, Graz, Austria.
authors.forename: Rainer
authors.initials: R
authors.lastname: Hofmann-Wellenhof
keywords: blue nevus; cutaneous melanoma metastasis; dermoscopy; foreign body reaction; malignant melanoma; optical coherence tomography; reflectance confocal microscopy