6. Histological diagnosis of tumors

Question 1

What is the significance of post-operative pathological diagnostic methods?

Answer 1

macro- and microscopic examination of the surgical speciment is used to specify diagnosis and define histoligical parameters for staging, further prognostic or predictive values

Question 2

Information collected from macroscopy

Answer 2

• tissue sample orientation and marking/staining of the surgical margin
• record tumor size and determine if there is any lesion left after neoadjuvant therapy

Question 3

Information collected from histology

Answer 3

• review clinical data, specify tumor type, analyze additional procedures
• prepare histological report

Question 4

Eight components of histopathological report for most solid tumors

Answer 4

1. diagnosis
2. tumor size
3. histological grade
4. vascular invasion
5. perineural invasion
6. surgical margin status
7. lymph node status
8. TNM classification and staging

Question 5

How is tumor size measured?

Answer 5

• important prognostic factor
• can be measured both by macro- or microscopic examination

Question 6

What is the importance of tumor histological grade?

Answer 6

• important prognostic factor
• helps in differentiation of tumor and provides information on its biological behavior

Question 7

How is histological grade determined?

Answer 7

determined by tumor similarity to the cell/tissue it developed from (i.e. bloom richardson system for breast cancer, gleason for prostate cancer)

Question 8

What is vascular invasion?

Answer 8

• presence of tumor cells in the blood or lymph
• provides information of the recurrence risk and lymph node or organ metastasis

Question 9

What is the significance of lymph node status?

Answer 9

• important prognostic factor (size, number and localization
• in most cancers (except papillary thyroid cancer), it is the most important risk factor in the progression of the disease
• in breast carcinoma or melanoma, sentinal lymph node status is very important in indicating the status of distal lymph nodes

Question 10

What is the most important prognostic factor of solid tumors?

Answer 10

TNM classification and staging