Describing and interpreting gross lesions

Prepared for VPM 4600, May 2018; Shannon Martinson

• Morphologic Diagnosis: • Organ

• Exudate (if present)

• Distribution

• Duration

• Extent

Step 1 • Look at the specimen: Is it normal or abnormal

Step 2 • What’s the abnormal part?

Step 3 • Describe the abnormal part

Step 4 • Interpret the changes (give a morphologic diagnosis)

How to Describe (and Interpret) Lesions

And then you think about ETIOLOGY or cause of disease and the PATHOGENESIS

• Description: • Location

• Distribution

• Shape / Contour

• Size / weight

• Consistency/texture

• Special features

• Extent

Location Organ or tissue involved and topography / aspect of tissue involved

http://wikieducator.org/images/c/c3/Directional_terms.JPG www.bodyteen.com/img/fan/terms/SupVsDeep.gif

Distribution The spatial arrangement of the lesion

Distribution The spatial arrangement of the lesion

Normal

Focal

Multifocal

Multifocal to coalescing

Locally extensive

Diffuse

Shape and Contour

We include the shape (round, irregular, square, etc) along with the contour (whether a lesion is raised or depressed relative to the surrounding tissue)

These lesions are round to irregular nodules that are often raised from the surface. Occasionally the center of the nodules are indented (umbilicated)

Size and weight Either measure or estimate the size of lesions or affected organs (ie whether organs are decreased or increased in size)

The kidney on the right (~ 2.5-3 cm x 4-5cm) is much smaller than the kidney on the left (4-5cm x 10-12cm).

Either the kidney on the left is smaller than normal or the kidney on the right is larger than normal

Colour You don’t need an explanation for this one…..but we often use modifiers

Mottled A patchy mixture of at least two colors

Streaked Linear discoloration

Stippled Finely spotted

Dark/or Bright To better characterize the color

The lungs are mottled pale pink, bright pink and yellow. The interlobular septa are expanded and white.

The implications of certain colors:

Red to dark purple

Usually means blood or hemoglobin pigment is present (congestion or hemorrhage)

Colour You don’t need an explanation for this one…..but we often use modifiers

The implications of certain colors:

White to Gray or Yellow

Often implies a lack of blood. Dead (necrotic) tissue is white to grey. Exudates are often yellow. Scar tissue is often white to tan.

Colour You don’t need an explanation for this one…..but we often use modifiers

The implications of certain colors:

Black Usually due to the presence of melanin (pigment)

Green Postmortem artifact, Bile staining, Fungal infections

Colour You don’t need an explanation for this one…..but we often use modifiers

Consistency/ Texture How does the organ feel? Soft, firm, hard…. What does the surface look like? Rough, smooth

Difficult to appreciate in a picture!

• Soft – like your cheek

• Firm – like your nose

• Hard - like your forehead

• Things that glisten are wet, things that are crepitus have air bubbles….

Special Features – cut surface

Cystic (containing cavities), multiloculated (having many cysts or cavities), fasciculated (forming bundles), etc…

Extent Estimate a proportion of the organ or tissue that is affected

Approximately 70 – 80 % of the right lung is affected

Anything can be described and you don’t necessarily have to include medical terms!

The object is ovoid, ~ 4 – 5 cm long and ~ 2.5 – 3 cm wide. It is green and fuzzy with sparse brown hair like structures arising from the surface.

Anything can be described and you don’t necessarily have to include medical terms!

On section, the object is round with a slightly irregular, well demarcated, pale yellow center surrounded by a 1 – 1.5 cm thick bright green rim. Dispersed evenly at the junction between the two, are numerous, small (1 – 2mm), black, ovoid structures separated by radiating pale bands.

With a good description - I should be able to identify the object (lesion) without seeing it

There is dark red discoloration and firm consolidation of the cranioventral and caudoventral aspects of the right lung involving approximately 70 – 80% of the lung field. The dorsal aspects of the lung are bright red.

Gross Pathology Descriptions

Arising from the mucosal surface of the bladder wall and filling the lumen is a pedunculated, firm, tan, solid, fasciculated mass that measures approximately 4 cm x 3 cm x 3 cm.

Gross Pathology Descriptions

At the cranial pole of the kidney, there is a focal wedge shaped region of tan-orange discoloration with indentation of the capsular surface. The affected area measures 1 x 2 x 2 cm. A similar smaller (0.5 cm) focus is present at the opposite pole.

Gross Pathology Descriptions

Adhered to the pleural surface of the right lung is a thick layer of friable yellow material. There is dark pink to dark red discolouration of the cranioventral and caudoventral aspects of the lung, involving ~ 80 – 90 % of the total lung field. Yellow fluid fills the thorax.

Gross Pathology Descriptions