TY - JOUR
T1 - Cutaneous tumoural melanosis
T2 - a presentation of complete regression of cutaneous melanoma
AU - Ching, Daniel
AU - Amini, Elham
AU - Harvey, Nathan Tobias
AU - Wood, Benjamin Andrew
AU - Mesbah Ardakani, Nima
PY - 2019/6/1
Y1 - 2019/6/1
N2 - Partial regression is common in cutaneous melanoma; however, complete regression manifesting as tumoural melanosis is rare, conceptually challenging and under-reported. In this study we report on clinical, histological and molecular findings in four cases of completely regressed cutaneous melanoma with nodal or brain metastasis, followed by a comprehensive review of the literature. Our series included three women and one man with an average age of 60 years, and clinical presentation with hyper-pigmented cutaneous lesions. The main histological findings were expansile aggregates of melanophages with complete absence of malignant melanocytes on microscopic and immunohistochemical examination of the entire primary skin lesions, as well as substantial reduction in the number of junctional melanocytes in the overlying epidermis. NRAS mutant/BRAF wild type metastatic deposits were identified in three patients, with one patient having a BRAF V600E mutant metastatic tumour. Tumoural melanosis likely represents a partially effective immunological response to melanoma, with complete eradication of cutaneous disease and less effective systemic results. Patients with tumoural melanosis should be managed as potential completely regressed cutaneous melanoma, with comprehensive physical examination, imaging work up and close follow up.
AB - Partial regression is common in cutaneous melanoma; however, complete regression manifesting as tumoural melanosis is rare, conceptually challenging and under-reported. In this study we report on clinical, histological and molecular findings in four cases of completely regressed cutaneous melanoma with nodal or brain metastasis, followed by a comprehensive review of the literature. Our series included three women and one man with an average age of 60 years, and clinical presentation with hyper-pigmented cutaneous lesions. The main histological findings were expansile aggregates of melanophages with complete absence of malignant melanocytes on microscopic and immunohistochemical examination of the entire primary skin lesions, as well as substantial reduction in the number of junctional melanocytes in the overlying epidermis. NRAS mutant/BRAF wild type metastatic deposits were identified in three patients, with one patient having a BRAF V600E mutant metastatic tumour. Tumoural melanosis likely represents a partially effective immunological response to melanoma, with complete eradication of cutaneous disease and less effective systemic results. Patients with tumoural melanosis should be managed as potential completely regressed cutaneous melanoma, with comprehensive physical examination, imaging work up and close follow up.
KW - BRAF mutations
KW - nodal melanosis
KW - NRAS mutations
KW - regressed melanoma
KW - Tumoural melanosis
UR - http://www.scopus.com/inward/record.url?scp=85064434457&partnerID=8YFLogxK
U2 - 10.1016/j.pathol.2019.01.008
DO - 10.1016/j.pathol.2019.01.008
M3 - Article
C2 - 31023480
AN - SCOPUS:85064434457
SN - 0031-3025
VL - 51
SP - 399
EP - 404
JO - Pathology
JF - Pathology
IS - 4
ER -