What do colours mean?

Tan – Many solid tumours are tan (beige to pale brown). This term is often used to describe the cut surface appearance of a solid tumour. This is one of our ‘favourite’ colours, particularly in very well fixed specimens! (In most specimens, you will be describing 50 shades of tan!)

Pale – An area of lighter colour on a slightly darker background e.g. areas of pallor superimposed on a tan tumour often indicate coagulative necrosis. Areas of infarction in solid organs are often pale – e.g. wedge-shaped pale infarct in the kidney. In a malignant tumour that grows rapidly and outstrips its blood supply, pale areas of necrosis may be seen within the tumour. (Go to the Practice! page to see an example in a kidney.)

Black

- Endogenous substances – e.g. blood – haemorrhagic areas are often dark brown to blackish. Melanin pigment is dark brown to blackish (hence a tumour mass that is blackish may represent a melanin-producing tumour, i.e. melanoma)

- Exogenous substances – carbon (e.g. in the lung, or in hilar lymph nodes), tattoo pigment

- Gangrene

(Go to the Practice! page to see an example in a lung.)

Green

- Processes involving bile accumulation, e.g. biliary cirrhosis, biliary obstruction, bile in the gallbladder

Yellowish green

- Purulent material, e.g. abscess fluid, fibrinopurulent serosal exudates in acute appendicitis

White

- Fibrosis, e.g. fibrous scar (may appear greyish white)

- Cartilage

- Fibrin, e.g. pale whitish areas in an arterial thrombus – lines of Zahn – whitish layers are platelets and fibrin

- Chalky whitish deposits – calcifications, e.g. pancreatic fat necrosis

Bright yellow

- Fat necrosis

Nature of localised lesions

Describing localised lesions depends on the organ that you are examining.

Solid organs (e.g. liver, spleen, lung):

• Nodule – Space-occupying condensation of tissue, often rounded and well circumscribed
• Mass – Space-occupying growth, can be well circumscribed or irregular
• Cyst – A usually rounded cavity with a smooth inner lining (cysts are lined by epithelium on their luminal surfaces), containing fluid
• Cavity – A hollow space within an organ, e.g. abscess cavity
• Area of discolouration – e.g. wedge-shaped area of pallor (infarct)

Organs with an epithelial lining, with underlying layers of tissue, e.g. skin, gastrointestinal tract, urinary bladder:

• Ulcer – A break in skin or mucous membrane with loss of surface tissue, disintegration and necrosis of epithelial tissue, and often pus.
  • Describing an ulcer: Edges – fungating (raised fleshy irregular edges) / punched out / rounded / irregular; Base – smooth / necrotic
• Polypoid growth
• Scar
• Plaque
• Area of discolouration: bruise, haemorrhage

Describing texture:

Friable – Easily torn apart or crumbled (used to describe areas of necrosis or tumours)

Fleshy – Solid, dense appearing

Spongy – Full of small holes, e.g. haemangioma

Solid