Background: How to deal with melanoma of unknown primary (MUP) origin is a debated topic in the literature. Objective: We performed a worldwide survey to inquire what clinical and investigational workup is performed as well as the physicians' perception of this disease. Methods: A questionnaire was sent via mail to clinicians involved in melanoma care from December 2015 to April 2016 using the International Dermoscopy Society website. Results: 119 physicians from 47 different countries answered the questionnaire. The most reported examination was skin examination followed by CT and/or PET scans. All the participants declared asking about previous excisions of skin lesions with 81% of them asking for a histopathological slide review of previous biopsies. Half of the participants checked for a possible vitiligo phenomenon that may explain regression of the primary lesion. BRAF, cKIT, and GNAQ mutations were screened by 32% of participants. The majority of participants (76%) applied the same treatment protocols for MUP as patients with known primary melanomas of the same AJCC stage. Conclusion: Strong heterogeneity was found between physicians dealing with MUP. Thus, a consensus document should be strongly encouraged.

1.
Kamposioras K, Pentheroudakis G, Pectasides D, Pavlidis N: Malignant melanoma of unknown primary site: to make the long story short - a systematic review of the literature. Crit Rev Oncol Hematol 2011;78:112-126.
2.
Pack GT, Gerber DM, Scharnagel IM: End results in the treatment of malignant melanoma: a report of 1,190 cases. Ann Surg 1952;136:905-911.
3.
Das Gupta T, Bowden L, Berg JW: Malignant melanoma of unknown primary origin. Surg Gynecol Obstet 1963;117:341-345.
4.
Anbari KK, Schuchter LM, Bucky LP, Mick R, Synnestvedt M, Guerry D 4th, Hamilton R, Halpern AC: Melanoma of unknown primary site: presentation, treatment, and prognosis - a single institution study. University of Pennsylvania Pigmented Lesion Study Group. Cancer 1997;79:1816-1821.
5.
Chang P, Knapper WH: Metastatic melanoma of unknown primary. Cancer 1982;49:1106-1111.
6.
Bae JM, Choi YY, Kim DS, Lee JH, Jang HS, Lee JH, Kim H, Oh BH, Roh MR, Nam KA, Chung KY: Metastatic melanomas of unknown primary show better prognosis than those of known primary: a systematic review and meta-analysis of observational studies. J Am Acad Dermatol 2015;72:59-70.
7.
Balch CM, Gershenwald JE, Soong SJ, Thompson JF, Atkins MB, Byrd DR, Buzaid AC, Cochran AJ, Coit DG, Ding S, Eggermont AM, Flaherty KT, Gimotty PA, Kirkwood JM, McMasters KM, Mihm MC Jr, Morton DL, Ross MI, Sober AJ, Sondak VK: Final version of 2009 AJCC melanoma staging and classification. J Clin Oncol 2009;27:6199-6206.
8.
Ribero S, Longo C, Glass D, Nathan P, Bataille V: What is new in melanoma genetics and treatment? Dermatology 2016;232:259-264.
9.
Laveau F, Picot MC, Dereure O, Guilhou JJ, Guillot B: Metastatic melanoma of unknown primary site. Ann Dermatol Venereol 2001;128:893-898.
10.
Savoia P, Fava P, Osella-Abate S, Nardò T, Comessatti A, Quaglino P, Bernengo MG: Melanoma of unknown primary site: a 33-year experience at the Turin Melanoma Center. Melanoma Res 2010;20:227-232.
11.
Clerico R, Bottoni U, Paolino G, Ambrifi M, Corsetti P, Devirgiliis V, Calvieri S: Melanoma with unknown primary: report and analysis of 24 patients. Med Oncol 2012;29:2978-2984.
12.
Prens SP, van der Ploeg AP, van Akkooi AC, van Montfort CA, van Geel AN, de Wilt JH, Eggermont AM, Verhoef C: Outcome after therapeutic lymph node dissection in patients with unknown primary melanoma site. Ann Surg Oncol 2011;18:3586-3592.
13.
Ribero S, Osella-Abate S, Sanlorenzo M, Savoia P, Astrua C, Cavaliere G, Tomasini C, Senetta R, Macripò G, Bernengo MG, Quaglino P: Favourable prognostic role of regression of primary melanoma in AJCC stage I-II patients. Br J Dermatol 2013;169:1240-1245.
14.
Ribero S, Moscarella E, Ferrara G, Piana S, Argenziano G, Longo C: Regression in cutaneous melanoma: a comprehensive review from diagnosis to prognosis. J Eur Acad Dermatol Venereol 2016;30:2030-2037.
15.
Tos T, Klyver H, Drzewiecki KT: Extensive screening for primary tumor is redundant in melanoma of unknown primary. J Surg Oncol 2011;104:724-727.
16.
Gos A, Jurkowska M, van Akkooi A, Robert C, Kosela-Paterczyk H, Koljenović S, Kamsukom N, Michej W, Jeziorski A, Pluta P, Verhoef C, Siedlecki JA, Eggermont AM, Rutkowski P: Molecular characterization and patient outcome of melanoma nodal metastases and an unknown primary site. Ann Surg Oncol 2014;21:4317-4323.
17.
Egberts F, Bergner I, Krüger S, Haag J, Behrens HM, Hauschild A, Röcken C: Metastatic melanoma of unknown primary resembles the genotype of cutaneous melanomas. Ann Oncol 2014;25:246-250.
18.
Blum A, Simionescu O, Argenziano G, Braun R, Cabo H, Eichhorn A, Kirchesch H, Malvehy J, Marghoob AA, Puig S, Ozdemir F, Stolz W, Tromme I, Weigert U, Wolf IH, Zalaudek I, Kittler H: Dermoscopy of pigmented lesions of the mucosa and the mucocutaneous junction: results of a multicenter study by the International Dermoscopy Society (IDS). Arch Dermatol 2011;147:1181-1187.
19.
Hofmann-Wellenhof R: Special criteria for special locations. 2. Scalp, mucosal, and milk line. Dermatol Clin 2013;31:625-636, ix.
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.