Breast pathology Flashcards
- A 44-year-old woman presents with a breast lump.
a. What is the likely differential diagnosis? (6 marks)
Fibroadenoma, fibrocystic changes, fat necrosis, intraductal papilloma and breast malignancy.
b. After a mammogram, the radiologist is not certain of the diagnosis. What needs to be done to determine the exact diagnosis? (3 marks)
A core biopsy of the lump needs to be obtained, this is preferred to breast fine needle aspiration (FNA) since it has similar complication but yields better results as its more sensitive and specific. In addition to a core biopsy a sentinel lymph node FNA is usually obtained in conjunction and sent to cytology for evaluation.
c. After a diagnosis of cancer has been made, the patient undergoes a wide local excision and sentinel lymph node biopsy. What does this mean? (7 marks)
These biopsies were performed as the core needle biopsy and/or FNA of sentinel lymph node were positive for malignancy. A wide local excision biopsy should removal all malignant cell from breast tissue as part of therapy. Sentinel lymph node biopsy is removal of one or more lymph nodes that are close to the malignant lesions. These are observed microscopically to ensure the tumour was fully removed and detect metastasis into the lymphatic system. This helps with staging the disease, if tumour cells are present the stage is increased.
d. Hormone receptors are performed by the laboratory on the tumour. Which immunostaining tests are these? (4 marks)
a) oestrogen receptor (ER)
b) progesterone receptor (PR)
c) human epidermal growth factor receptor-2 (HER-2)
e. Why is it important to assess the hormone receptors? (5 marks)
The assessment of these stains is based on the ALLRED score which depends on the proportion and intensity for ER and PR and intensity score for human epidermal growth factor receptor-2 (HER-2). These scores will help determine if the patient is eligible for hormone therapy, for instance if tumour is ER positive, the patient may be given tamoxifen or other anti-oestrogen drugs. They are also prognostic indicators, for instance triple-negative breast cancers (ER-/PR-/HER-2-) have a worse prognosis than (ER+/PR+/HER-2-).
- A 52-year old woman is called for mammography as part of the breast screening programme. The mammogram shows an area of calcifications and a core biopsy of this area is taken. The pathologist reports that there is ‘ductal carcinoma in situ’.
a) What do you understand by ‘carcinoma in situ’? (5 marks)
Carcinoma in situ means that there is the presence of malignant cells, however, they have not yet breached the basement membrane, nor myoepithelial cells in case of breast and remained confined in the original area in the breast.
b) Apart from ductal carcinoma in situ, which is the other main type of carcinoma in situ seen in the breast? (2 marks)
Lobular carcinoma in situ
c) The lesion was next removed surgically and apart from the carcinoma in situ, Grade 2 invasive ductal carcinoma was also present. How do you explain that invasive carcinoma is present when it was not seen in the core biopsy? (4 marks)
This is because a core needle biopsy is an incisional biopsy and is only used to obtain a representative sample of the lesion making it less sensitive than a whole resection of the tumour. Moreover, ductal carcinoma in situ can co-exist with ductal carcinoma it can be missed when sampling. It was detected when the tumour was surgically removed since it is an excisional biopsy, thus, the whole extent of the lesion is removed.
d) Which immunostains need to be performed on the tumour at the histopathology laboratory to determine prognosis and treatment? (5 marks)
oestrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (HER-2). The assessment of these stains is based on the ALLRED score which depends on the proportion and intensity for ER and PR and intensity score HER-2. These scores will help determine if the patient is eligible for hormone therapy, for instance if tumour is ER positive, the patient may be given tamoxifen or other anti-oestrogen drugs. They are also prognostic indicators, for instance triple-negative breast cancers (ER-/PR-/HER-2-) have a poorer prognosis than (ER+/PR+/HER-2-).
e) Following the diagnosis of invasive ductal carcinoma, axillary lymph nodes were removed. Why was this done? (4 marks)
Axillary lymph nodes are sentinel lymph nodes, which means that they are close to the malignancy and malignant cells could have metastasised to these nodes. These are observed microscopically to determine if there was invasion from malignant cells, thus detect metastasis into the lymphatic system which aids in staging the disease. The presence of tumour cells in lymph nodes upstages the disease.
f) What is the difference between grading and staging of a tumour? (5 marks)
The grade of the tumour is based on morphological appearance of malignant cells, that is the degree of differentiation; a well-differentiated tumour is graded as grade 1 while a poorly-differentiated tumour is grade 3. For instance, a well-differentiated squamous cell carcinoma of the lung there is the presence of keratin, while a poorly-differentiated squamous cell carcinoma does not have keratin and may be difficult to distinguish from adenocarcinoma based on H&E and without Immunohistochemistry.
The stage of the tumour is based on the size of the primary lesions and the extent to which it invaded based on lymph node and other metastasis. Metastasis can be determined by histological means or radiology. The larger the tumour size and the more invasive, the higher the stage of the cancer.
- A 55-year old healthy woman attends the breast screening unit for a screen mammogram. The mammogram shows abnormal calcification which are worrying for the radiologist who decides to perform a biopsy.
a. What are the most likely diagnoses? (4 marks)
Ductal carcinoma in situ and invasive ductal carcinoma are the most common causes of calcifications on mammogram.
However, other causes of calcifications include sclerosing adenosis, lobular neoplasia, atypical ductal hyperplasia, atypical ductal hyperplasia, pleomorphic lobular carcinoma in situ, atypical lobular hyper-plasia, and papilloma.
b. What is the definitive diagnosis? (3 marks)
Invasive ductal carcinoma
