Skip to main content Accessibility help

Animal-type melanoma: dog or wolf? A review of the literature and a case report

  • Luigia Stefania Stucci (a1), Raffaele Palmirotta (a1), Domenica Lovero (a1), Erica Silvestris (a1), Paola Cafforio (a1), Claudia Felici (a1), Annalisa Todisco (a1), Eleonora Nacchiero (a2), Federica Pezzuto (a3), Marco Tucci (a1) and Franco Silvestris (a1)...


The human animal type melanoma (ATM) is a rare subtype of melanoma characterised by the proliferation of pigmented dermal epithelioid and spindled melanocytes. However, this variant of melanoma is still lacking a precise nosography definition and classification for the difficulty to be distinguished from other more common melanocytic lesions, as well as for its peculiar biological behaviour. On the other hand, the contribution of scientific literature to this issue is fragmented and limited to the description of very few cases. Starting from the presentation of a case with abnormally aggressive clinical features, here we revisit the current knowledge on ATM from its dermatologic patterns, epidemiology, demography and histopathology to the clinical management. Peculiar accuracy has also been reserved to several histopathologic criteria, which are critical for the differential diagnosis from other melanocytic diseases in junction with molecular data deriving from recent cytogenetic and mutational characterisation of this tumour.


Corresponding author

Author for correspondence: Raffaele Palmirotta, E-mail:


Hide All
1.LeBoit, PE, Burg, G, Weedon, D and Sarasin, A (2014) Pathology and Genetics of Tumours of the Skin. WHO Classidication of Tumours. USA: International Agency for Research on Cancer. IARC Press, USA.
2.Crowson, AN, Magro, CM and Mihm, MC Jr (1999) Malignant melanoma with prominent pigment synthesis: “animal type” melanoma--a clinical and histological study of six cases with a consideration of other melanocytic neoplasms with prominent pigment synthesis. Human Pathology 30, 543550.
3.Massi, GLPE (2013) Histological diagnosis of nevi and melanoma, 2013 edition.
4.Vyas, R et al. (2015) A systematic review and meta-analysis of animal-type melanoma. Journal of the American Academy of Dermatology 73, 10311039.
5.Dick, W (1832) Melanosis in men and horses. Lancet 19, 192.
6.Darier, J (1925) Le melanome malin mesenchymateaux ou melanosarcome. Bull Assoc Fr Cancer 14, 221249.
7.Tuthill, RJ, Clark, WH Jr and Levene, A (1982) Pilar neurocristic hamartoma: its relationship to blue nevus and equine melanotic disease. Archives of Dermatology 118, 592596.
8.Clark, WH, Elder, DE and Guerry, D (1990) Dysplastic nevi and malignant melanoma, Pathology of the Skin. Appleton and Lange, East Norwalk, CT, pp. 684756
9.Zembowicz, A, Carney, JA and Mihm, MC (2004) Pigmented epithelioid melanocytoma: a low-grade melanocytic tumor with metastatic potential indistinguishable from animal-type melanoma and epithelioid blue nevus. American Journal of Surgical Pathology 28, 3140.
10.Stratakis, CA (2016) Carney complex: a familial lentiginosis predisposing to a variety of tumors. Reviews in Endocrine & Metabolic Disorders 17, 367371.
11.Gavriilidis, P et al. (2013) Pigmented epithelioid melanocytoma: a new concept encompassing animal-type melanoma and epithelioid blue nevus. BMJ Case Rep 2013.
12.Battistella, M et al. (2010) Two congenital cases of pigmented epithelioid melanocytoma studied by fluorescent in situ hybridization for melanocytic tumors: case reports and review of these recent topics. Dermatology (Basel, Switzerland) 221, 97106.
13.Sestini, S et al. (2012) ‘Animal-type’ melanoma of the scalp with satellitosis and positive sentinel nodes in a 4-year-old child: case report and review of the literature. Journal of Plastic, Reconstructive & Aesthetic Surgery 65, e90e94.
14.AL-Johani, TAAA (2014) Pigmented epithelioid melanocytoma – A case report. IAIM 1, 3638.
15.Sabah, M, Leader, M, Fahy, M and Kay, E (2007) Animal-Type Melanoma: a rare type of malignant melanoma with an indolent clinical behaviour. Clinical Medicine: Oncology 1, 9598.
16.Lim, C et al. (2010) Pigmented epithelioid melanocytoma: a recently described melanocytic tumour of low malignant potential. Pathology 42, 284286.
17.Cheng, P-S et al. (2012) Pigmented epithelioid melanocytoma: report of a case and review of 173 cases in the literature. Dermatologica Sinica 30, 5761.
18.Urso, C et al. (2014) Animal-type melanoma: report of five cases with sentinel node biopsy and fluorescence in-situ hybridization analysis. Melanoma Research 24, 4753.
19.Akita, R et al. (2016) Case report of a large pigmented epithelioid melanocytoma with suspected lymph node metastases. Eplasty 16, e33.
20.Mandal, RV et al. (2009) Pigmented epithelioid melanocytoma: favorable outcome after 5-year follow-up. American Journal of Surgical Pathology 33, 17781782.
21.Marques, YM et al. (2009) Blue nevus: report of a case. General Dentistry 57, e1e3.
22.Ranabhat, S et al. (2014) Survival for 38 years with animal-type malignant melanoma. Journal of Pathology of Nepal 4, 685687.
23.Bissig, A et al. (2012) Conjunctival pigmented epithelioid melanocytoma: a clinicopathological case report. Archives of Ophthalmology 130, 14781479.
24.Kumar, SK et al. (2008) Oral mucosal melanoma with unusual clinicopathologic features. Journal of Cutaneous Pathology 35, 392397.
25.Nitta, K et al. (2014) Animal-type malignant melanoma associated with nevus of Ota in the orbit of a Japanese woman: a case report. Melanoma Research 24, 286289.
26.Aviles-Izquierdo, JA, Leis-Dosil, VM and Lazaro-Ochaita, P (2014) Animal-type melanoma: clinical and dermoscopic features of 3 cases. Actas Dermo-sifiliograficas 105, 186190.
27.Moscarella, E et al. (2016) Pigmented epithelioid melanocytoma: clinical, dermoscopic and histopathological features. British Journal of Dermatology 174, 11151117.
28.Sevilla Chica, F, Bernett, L et al. (2015) Melanocitoma epitelioide pigmentado: diagnostico diferencial y tratamiento. Medicina cutanea ibero-latino-americana 43, 187191.
29.Moyano de Fossati, L (2010) Melanoma de tipo animal. Dermatol Argent 16, 354358.
30.Howard, B, Ragsdale, B and Lundquist, K (2005) Pigmented epithelioid melanocytoma: two case reports. Dermatology Online Journal 11, 1.
31.Lee, JJ et al. (2017) 5-Hydroxymethylcytosine is a nuclear biomarker to assess biological potential in histologically ambiguous heavily pigmented melanocytic neoplasms. Journal of Cutaneous Pathology 44, 249255.
32.Sadayasu, A et al. (2013) Pigmented epithelioid melanocytoma: immunohistochemical profiles of tumour-infiltrating histiocytes. Acta Dermato-Venereologica 93, 481482.
33.Magro, CM, Crowson, AN and Mihm, MC (2006) Unusual variants of malignant melanoma. Modern Pathology 19 (Suppl. 2), S41S70.
34.Russo, D et al. (2012) Animal type melanoma: an unusual case with aggressive histological features? Pathology Research and Practice 208, 169171.
35.Pathy, AL et al. (1993) Malignant melanoma arising in a blue nevus with features of pilar neurocristic hamartoma. Journal of Cutaneous Pathology 20, 459464.
36.Ludgate, MW et al. (2010) Animal-type melanoma: a clinical and histopathological study of 22 cases from a single institution. British Journal of Dermatology 162, 129136.
37.Neelam, S et al. (2016) Pigmented epitheloid melanocytoma: a low grade/intermediate/borderline melanoma. International Surgery Journal 3, 400403.
38.Posch, C et al. (2012) Animal-type melanoma – tumor cell invasion of dermal lymphatics and molecular identification of lymph node metastasis. Journal der Deutschen Dermatologischen Gesellschaft 10, 3841.
39.Aung, PP et al. (2015) Differential diagnosis of heavily pigmented melanocytic lesions: challenges and diagnostic approach. Journal of Clinical Pathology 68, 963970.
40.Antony, FC et al. (2006) Pigment synthesizing melanoma (so-called animal type melanoma): a clinicopathological study of 14 cases of a poorly known distinctive variant of melanoma. Histopathology 48, 754762.
41.Bagny, K et al. (2013) Animal-type melanoma with regional lymph node metastasis after a 5-year follow-up. International Journal of Dermatology 52, 9092.
42.Matthey-Gie, ML et al. (2013) Sentinel lymph node biopsy in nonmelanoma skin cancer patients. Journal of Skin Cancer 2013, 267474.
43.Mentzel, T (2007) Ungewöhnliche Formvarianten maligner melanozytärer Tumoren. Der Pathologe 28, 445452.
44.Morton, DL et al. (2006) Sentinel-node biopsy or nodal observation in melanoma. New England Journal of Medicine 355, 13071317.
45.Orlandi, A et al. (2009) Relation between animal-type melanoma and reduced nuclear expression of glutathione S-transferase pi. Archives of Dermatology 145, 5562.
46.Scolyer, RA et al. (2004) Pigmented epithelioid melanocytoma. American Journal of Surgical Pathology 28, 11141115; author reply 15–6.
47.Balch, CM et al. (2001) Prognostic factors analysis of 17,600 melanoma patients: validation of the American Joint Committee on Cancer melanoma staging system. Journal of Clinical Oncology 19, 36223634.
48.Scolyer, RA et al. (2010) Histologically ambiguous (“borderline”) primary cutaneous melanocytic tumors: approaches to patient management including the roles of molecular testing and sentinel lymph node biopsy. Archives of Pathology & Laboratory Medicine 134, 17701777.
49.Dadras, SS (2011) Molecular diagnostics in melanoma: current status and perspectives. Archives of Pathology & Laboratory Medicine 135, 860869.
50.Zembowicz, A and Scolyer, RA (2011) Nevus/Melanocytoma/Melanoma: an emerging paradigm for classification of melanocytic neoplasms? Archives of Pathology & Laboratory Medicine 135, 300306.
51.Zembowicz, A et al. (2007) Loss of expression of protein kinase a regulatory subunit 1alpha in pigmented epithelioid melanocytoma but not in melanoma or other melanocytic lesions. American Journal of Surgical Pathology 31, 17641775.
52.Bender, RP et al. (2013) Identification of HRAS mutations and absence of GNAQ or GNA11 mutations in deep penetrating nevi. Modern Pathology 26, 13201328.
53.Bahrami, A et al. (2016) Pigment-synthesizing melanocytic neoplasm with protein kinase C alpha (PRKCA) fusion. JAMA Dermatology 152, 318322.
54.Muhlbauer, A et al. (2017) The correlation of the standard 5 probe FISH assay with melanocytic tumors of uncertain malignant potential. Annals of Diagnostic Pathology 28, 3036.
55.Bax, MJ et al. (2017) Pigmented epithelioid melanocytoma (animal-type melanoma): an institutional experience. Journal of the American Academy of Dermatology 77, 328332.
56.Palmirotta, R et al. (2014) Diagnostic procedures for paraffin-embedded tissues analysis in pharmacogenomic studies. Methods in Molecular Biology 1175, 4565.
57.Kirschner, LS et al. (2000) Genetic heterogeneity and spectrum of mutations of the PRKAR1A gene in patients with the carney complex. Human Molecular Genetics 9, 30373046.
58.Palmirotta, R et al. (2017) Next-Generation Sequencing (NGS) analysis on single Circulating Tumor Cells (CTCs) with no need of Whole-Genome Amplification (WGA). Cancer Genomics & Proteomics 14, 173179.
59.Margaryan, NV et al. (2016) Melanocytes affect nodal expression and signaling in melanoma cells: a lesson from pediatric large congenital melanocytic nevi. International journal of molecular sciences 17, 418.
60.Cancer Genome Atlas, N (2015) Genomic classification of cutaneous melanoma. Cell 161, 16811696.


Related content

Powered by UNSILO

Animal-type melanoma: dog or wolf? A review of the literature and a case report

  • Luigia Stefania Stucci (a1), Raffaele Palmirotta (a1), Domenica Lovero (a1), Erica Silvestris (a1), Paola Cafforio (a1), Claudia Felici (a1), Annalisa Todisco (a1), Eleonora Nacchiero (a2), Federica Pezzuto (a3), Marco Tucci (a1) and Franco Silvestris (a1)...


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.