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Malignant Melanoma

- See: Tumors of Soft Tissue

- Prognosis:
    - prognosis of malignant melanoma worsens w/ increasing tumor thickness and also appears to be related to tumor site, age, and sex;
    - lesions on the scalp, hands, and feet, particularly in older pts and males, all have a poorer prognosis;
    - tumor thickness & 5 year survival rate:
           - tumor thickness < 0.75 mm have > 95% survival rate;
           - tumor thickness > 4 mm have < 50% surviva ratel;
    - w/ nodal metastasis five-year survival rate declines to 36%;
    - w/ metastases survival is < 5%;
    - lymph nodes and lymphatic mapping:
           - useful for identifying metastasis to the sentinel lymph node;
           - observation that the classic lymph node dissection would not necessarily identify metastasis to the SLN (which was the case in 10/12 patients in the study by Joseph, et al (1999) 
           - in contrast, patients w/ a negative SLN can be spared the morbidity of a complete lymph node dissection;
           - references:
                   - Lymphatic mapping for melanomas of the upper extremity.  
                   - Sentinel-Node Biopsy or Nodal Observation in Melanoma.
                   - Prognostic factors in patients with melanoma metastatic to axillary or inguinal lymph nodes. A multivariate analysis.

- Junctional Nevi:
    - pigmented tumors w/ benign melanocytes in epidermis & arranged in nests;
    - acquired variety are smaller than 6 mm;
    - benign pigmented tumors usually do not produce discomfort or other functional deficit;

- Subungual Melanoma:
    - first described in 1886 by Jonathan Hutchinson who noted that though it looked like septic whitlow, lesion was malignant from beginning;
          - he noted thatt not all were pigmented but that at edges there was always slight black discoloration and this, however, slight, confirmed the diagnosis;
    - growth usually appears in the form of a black fungating ulcer involving the nail sulcus and matrix and elevating the nail;
    - black border along the edge of the nail is pathognomonic;
    - may appear as pigmented band originating from nail matrix;
    - in blacks and in some orientals pigmented bands may be normal, but pathology should be suspected in caucasions;
          - onset of pigmented band after the age of 40 is suspicious;
          - also remember that in blacks upto 25% of melanomas occur as subungual lesions;
    - in the report by O'Leary JA, et al (2000), 93 patients w/ diagnoses of subungual melanoma were followed w/ a median duration of followup of 5.2 years;
          - 83 % of patients presented with Stage I disease, whereas 17% had nodal or distant disease;
          - 53 % had locally advanced disease at presentation;
          - operative therapy consisted of amputation;
          - elective lymph node dissection was performed in 34 patients (37%) for Stage I tumors of intermediate thickness;
          - therapeutic node dissection was required in 16 patients (17%) for positive nodes
          - 5-year survival was 74% for patients with Stage I disease and 40% for patients with Stage II disease;
    - diff dx: (of nail hyperpigmentataion);
          - hematoma
          - chlorpromazine
          - antimalarial meds
          - heavy metal toxicity
          - Peutz-Jeghers Syndrome
    - treatment:
          - controversial;
          - when subungual melanoma involves the index nail, consider ray amputation since the index ray is functionally less important than the other rays;
    - references: 
          - NEJM Image Challenge - Subungual melanoma.
          - Surgical aspects of subungual malignant melanomas. The Scottish Melanoma Group.
          - Subungual melanoma. A review of 93 cases with identification of prognostic variables

Data on first recurrence after treatment for malignant melanoma in a large patient population.

Skeletal metastases of melanoma.

Medical Progress: Cutaneous Melanoma.

Melanoma recurrence after excision. Is a wide margin justified?

Efficacy of 2-cm surgical margins for intermediate-thickness melanomas (1 to 4 mm). Results of a multi-institutional randomized surgical trial.

Melanoma of the Foot.

Malignant melanoma of the foot and ankle.

Data on first recurrence after treatment for malignant melanoma in a large patient population.

Skeletal metastases of melanoma.

Excision Margins in High-Risk Malignant Melanoma.

Images in clinical medicine. Plantar melanoma--a false vegetant wart.