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