13.02.15 Plastics notes

Hilton's Law

    • Nerve that innervates a joint also tends to innervate the muscles that move the joint and the skin that covers the distal attachments of those muscles

    • For example, musculocutaneous nerve:

      • Supplies biceps brachii + brachialis

      • Also supplies the elbow joint with pain and proprioception fibres

      • Also supplies the forearm skin around the elbow (close to the insertion of each of those muscles)

Melanoma history

    • Age

    • Occupation

      • Outside work?

    • Country of birth

    • Past sun exposure

      • Sunburnt?

    • Skin type / Response to sun

    • History of lesion

      • When noticed

      • When GP consulted

      • Referrals

    • Any other moles

    • PMH

    • FHx of skin or other cancer

Fungating man

    • Differentials

      • SCC / MM

      • BCC never look like that

    • Smell

      • Farty smell = Anaerobes

        • => Metroniazole

Melanoma staging

    • Breslow thickness => 5-year survival

      • <1 mm => 95-100%

      • 1 - 2 mm => 80-96%

      • 2 - 4 mm => 60-75%

      • >4 mm => 50%

    • Ulceration is bad

    • Nodes

    • CT for haematogenous spread

Skin types (Fitzpatrick Scale)

    • Type I

      • Light, pale white

      • Always burns, never tans

    • Type II

      • White; fair.

      • Usually burns, tans with difficulty

    • Type III

      • Medium, white to light brown.

      • Sometimes mild burn, gradually tans to a light brown

    • Type IV

      • Olive, moderate brown

      • Rarely burns, tans with ease to a moderate brown

    • Type V

      • Brown, dark brown

      • Very rarely burns, tans very easily

    • Type VI

      • Black, very dark brown to black

      • Never burns, tans very easily, deeply pigmented

Seborrheic keratosis

    • Noncancerous benign skin growth

    • Originates in keratinocytes

    • Seen more often as people age

    • Appearance:

      • "Pasted on"

      • Various colors, from light tan to black

      • Round or oval

      • Feel flat or slightly elevated (like the scab from a healing wound)

      • Range in size from very small to more than 2.5 centimetres across

    • Resemble

      • Warts

      • Melanoma

Gastrointestinal stromal tumor (GIST)

    • Definition

      • Common GI mesenchymal tumor

        • 1-3% of all gastrointestinal malignancies

      • Defined as tumors whose behavior is driven by mutations in the Kit or PDGFRA genes

      • Sarcomas (connective tissue)

        • cf Most other GI tumours

      • 70-80% are benign

    • Signs and symptoms

      • Vague abdo pain

      • Trouble swallowing

      • GI bleed

      • Mets

      • Intestinal obstruction is rare, due to the tumor's outward pattern of growth

    • Location

      • 70% stomach

      • 20% small intestine

      • 10% oesophagus

    • Therapy

      • All GIST tumors should be considered to have malignant potential and no GIST tumor can be correctly classified as "benign."

      • Surgery is mainstay

      • c-kit tyrosine kinase inhibitor imatinib => 40-70% response rate in metastatic/inoperable cases

        • Initially marketed for CML

        • Also useful in dermatofibrosarcoma protuberans (DFSP)

Notes

    • Charcot joint

    • Eccrine porocarcinoma