A 60-year-old female presents to the emergency department with a chief complaint of “my mass is bleeding.” She believes the mass has been present for over a year but has been reluctant to seek medical attention. She has no past medical history but has lost about 20 pounds in the past year. Exam reveals a large pedunculated mass over the left posterior axillary line that is approximately the size of a grapefruit and appears to have significant vascularization. There are multiple areas of serosanguinous discharge and a small amount of bleeding.
What is the diagnosis?
The patient underwent a computed tomography (CT) scan of the chest, abdomen, and pelvis that revealed extensive lymphadenopathy in addition to the large exophytic mass thought to be likely sarcoma. There were also multiple metastatic subcutaneous deposits. She was taken to the operating room for removal, and histology confirmed a diagnosis of malignant melanoma. Further history revealed that the patient had spent much of her life outside working on the family farm.
After discharge home with oncology follow-up, she developed altered mental status. An MRI of the brain revealed the presence of multiple enhancing metastatic lesions. The patient was diagnosed with stage IV metastatic melanoma with an overall 1-year survival of 0%. Prognosis and treatment options were discussed, and the patient and family made the decision to start hospice. The patient expired 8 weeks later, approximately 10 weeks from the initial diagnosis.
The differential diagnosis for the patient’s mass consisted of multiple types of sarcomas, including dermatofibrosarcoma protuberans, liposarcoma, leiomyosarcoma, and dermal pleomorphic sarcoma. Additionally, due to the extensive history of sun exposure, melanoma was included in the differential diagnosis.
Melanoma results in more deaths than any other cancer, but accounts for less than 5% of all malignancies.1 It is the third most prevalent malignant skin tumor and arises from pigment producing melanocytes. The skin is the most common location for melanoma occurrence, however, they have also been found in the oral mucosa, the eye, and the gastrointestinal tract.2
There are many different risk factors for the development of melanoma, including excessive exposure to the sun, tanning beds, genetic predisposition (familial atypical multiple mole melanoma syndrome or FAMMM syndrome), multiple nevi, and immunosuppression.2,3 The most important risk factor is exposure to ultraviolet (UV) radiation via sun exposure or tanning beds. Of the three different types of UV radiation (UVA, UVB, and UVC), UVB radiation seems to be associated with the highest risk for developing melanoma due to its ability to directly penetrate the superficial layers of the skin and damage the melanocyte’s DNA.
UVA can cause a similar cascade of events in melanocytes, but to a much lesser extent because it is not readily absorbed into the cell as well as UVB due to its longer wavelength.4,5 The melanin produced by melanocytes acts as a protective mechanism to combat the mutagenic effects of UV radiation on DNA.
Since melanocytes are derived from neural crest cells, they contain various S100 proteins. S100 proteins are found in specific types of cells including adipocytes, dendritic cells, keratinocytes, macrophages, Langerhans cells, Schwann cells, and melanocytes.7 Melan-A (MART-1) is an antigen that is targeted by cytotoxic T-cells and expressed in both benign and malignant lesions exclusively of melanocytic origin. Used in conjunction with the S100 marker, this allows for the definitive diagnosis of melanoma.8
According to data from 2006-2012, with proper management, the overall 5-year survival rate of very early-stage melanoma is 91.5%. However, as the cancer metastasizes to regional, and then distant lymph nodes, the 5-year survival rate drops to 17.9%.9 Unfortunately our patient had waited far too long prior to seeking treatment.
Workup in the Emergency Department
A patient presenting with a lesion suspicious for malignancy requires a basic metabolic evaluation focused on the possibility of metastasis, including a complete blood count with differential (CBC), complete metabolic panel (CMP), lactate dehydrogenase (LAD), chest X-ray, and CT imaging of the chest, abdomen, and pelvis.
Additionally, the patient should be appropriately treated for any fluid and electrolyte abnormalities. Drainage from the tumor should be cultured to rule out any secondary skin infections prior to admission. Pain should be addressed, and a surgical consult can be ordered to obtain a biopsy for pathological evaluation and possible tumor removal.
- Cancer facts & figures 2014, (2014). http://www.cancer.org/acs/groups/content/@research/documents/webcontent/acspc-042151.pdf. Accessed December 31, 2016.
- Melanoma treatment (PDQ®) – PubMed health – national library of medicine – PubMed health. April 2016. https://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0032516/. Accessed December 31, 2016.
- Lynch HT, Fusaro RM, Pester J, Lynch JF. Familial atypical multiple mole melanoma (FAMMM) syndrome: Genetic heterogeneity and malignant melanoma. British Journal of Cancer. 1980;42(1):58–70. doi:10.1038/bjc.1980.203.
- WHO. UV radiation. World Health Organization. http://www.who.int/uv/faq/whatisuv/en/index2.html. Accessed December 31, 2016.
- Wang SQ, Setlow R, Berwick M, et al. Ultraviolet A and melanoma: A review. Journal of the American Academy of Dermatology. 2001;44(5):837–846. doi:10.1067/mjd.2001.114594.
- Leslie MC, Bar-Eli M. Regulation of gene expression in melanoma: New approaches for treatment. Journal of Cellular Biochemistry. 2004;94(1):25–38. doi:10.1002/jcb.20296.
- Wolf R, Ruzicka T, Yuspa SH. Novel S100A7 (psoriasin)/S100A15 (koebnerisin) subfamily: Highly homologous but distinct in regulation and function. Amino Acids. 2010;41(4):789–796. doi:10.1007/s00726-010-0666-4.
- Busam KJ, Chen Y-T, Old LJ, et al. Expression of Melan-A (MART1) in benign Melanocytic Nevi and primary Cutaneous malignant Melanoma. The American Journal of Surgical Pathology. 1998;22(8):976–982. doi:10.1097/00000478-199808000-00007.
- Melanoma. https://medlineplus.gov/melanoma.html. Accessed December 31, 2016.
- Tan W. Malignant Melanoma Workup: Approach considerations, Histologic findings, complete chemistry panel. Medscape. http://emedicine.medscape.com/article/280245-workup#showall. Accessed December 31, 2016.