Metastatic Melanoma Of Unknown Origin Research Articles

Posterior mediastinal melanoma causing severe dysphagia: A case report

IntroductionWe describe an original case of progressive severe dysphagia caused by a posterior mediastinal metastatic melanoma of unknown origin. To the best of our knowledge, such an event has never been described before in the literature.Case presentationA progressive severe dysphagia case is reported induced by a melanoma of unknown origin (metastatic to a posterior mediastinal lymph node). At the time of diagnosis, the lesion appeared as a large posterior mediastinal mass mimicking a neurogenic tumour with oesophageal involvement. After complete resection, pathological assessment of the tumour by immunohistochemistry was consistent with nodal metastatic melanoma.ConclusionThis report of a posterior mediastinal lymph node melanoma is unique. The nodal origin is definitely unusual: a primary melanoma should always be carefully ruled out. In fact no other evidence, a part from the absence of the tumour elsewhere, can support the diagnosis of a primary nodal melanoma.

Dermoscopy of fully regressive cutaneous melanoma

Metastatic melanoma of unknown origin is a difficult challenge diagnostically and therapeutically. Diagnosis of the putative primary lesion is difficult. This difficulty increases when the primary lesion has undergone complete regression. To define the dermoscopic features of fully regressed melanoma. A single-institution, register-based study of an unselected consecutive series of seven cases of metastatic melanoma in the lymph nodes with no known or visible primary lesion was carried out. Skin examination included dermoscopy; when a suspicious area was found, observed dermoscopic features were recorded and a biopsy was performed. Diagnosis of completely regressive cutaneous melanoma was based on clinical-pathological correlation according to widely accepted criteria. Seven dermoscopic features were associated with completely regressive melanoma: scar-like depigmentation (100%); pink coloration of the background (100%); linear-irregular vessels (86%); globular pattern of the vessels (43%); remnants of pigmentation (86%), either macular (43%) or with a peppering aspect (43%); and white lighter transverse bands (43%). The last feature was only observed with polarized light dermoscopy devices. Dermoscopy more accurately distinguishes the vascular, pigmentary and scarring changes of fully regressive melanoma. We believe that dermoscopy should be included in the search for a regressive primary lesion in case of metastatic melanoma of unknown origin.

Decorative sentinel lymph node: a new entity?

Malignant melanoma can be a difficult lesion to differentiate clinically. However, when it spreads to regional lymph nodes, there is usually a characteristic pigmentation of the node. We describe a case of an incidental finding of a pigmented lymph node while operating on an inguinal lymph node, which raised the possibility of there being a metastatic melanoma of unknown origin. Histologically, the observed pigmentation was due to the migration of a decorative tattoo pigment instead of malignant cells.