Unknown Primary Metastasis to the Axillary Nodes?
What is the recommended line of management for a 42-year-old woman who presented with isolated right axillary lymph node metastatic adenocarcinoma? The tumor is most likely of breast origin, although no primary could be found despite extensive investigations.
The most common primary site in a woman presenting with metastatic adenocarcinoma to the axillary lymph nodes is an occult breast primary. Other primary sites would include thyroid, lung, pancreas, and gastric or colon. It is important to bear in mind that of these possibilities, only a breast cancer diagnosis would still be potentially curable with axillary metastases.
Immunohistochemical staining for BRST-2 is not terribly sensitive, but is fairly specific and would be suggestive of a breast origin. Expression of other proteins such as BRST-2, estrogen-receptor (ER) or progesterone-receptor (PR) positivity, and Her2/neu expression would also support the presence of a breast primary.
Magnetic resonance imaging may be useful in identifying occult primary disease when other imaging modalities are negative. Color Doppler imaging and positron-emission tomography with 18-F-2-deoxyglucose (FDG PET) are being evaluated, although the latter may lack the sensitivity to detect small lesions.
Axillary dissection is generally recommended, and systemic adjuvant therapy should be prescribed as indicated by the biology of the disease (eg, ER/PR expression) and the risk of recurrence (eg, number of positive nodes). For a young woman with no comorbid illnesses, adjuvant systemic chemotherapy would clearly be indicated. With regard to management of the putative occult primary, mastectomy offers the advantages of confirming the diagnosis and treating the occult disease. When mastectomy is performed in these circumstances, an occult primary is found in about 70% of cases. Therapeutic options other than mastectomy include empiric breast irradiation.
What is the recommended line of management for a 42-year-old woman who presented with isolated right axillary lymph node metastatic adenocarcinoma? The tumor is most likely of breast origin, although no primary could be found despite extensive investigations.
The most common primary site in a woman presenting with metastatic adenocarcinoma to the axillary lymph nodes is an occult breast primary. Other primary sites would include thyroid, lung, pancreas, and gastric or colon. It is important to bear in mind that of these possibilities, only a breast cancer diagnosis would still be potentially curable with axillary metastases.
Immunohistochemical staining for BRST-2 is not terribly sensitive, but is fairly specific and would be suggestive of a breast origin. Expression of other proteins such as BRST-2, estrogen-receptor (ER) or progesterone-receptor (PR) positivity, and Her2/neu expression would also support the presence of a breast primary.
Magnetic resonance imaging may be useful in identifying occult primary disease when other imaging modalities are negative. Color Doppler imaging and positron-emission tomography with 18-F-2-deoxyglucose (FDG PET) are being evaluated, although the latter may lack the sensitivity to detect small lesions.
Axillary dissection is generally recommended, and systemic adjuvant therapy should be prescribed as indicated by the biology of the disease (eg, ER/PR expression) and the risk of recurrence (eg, number of positive nodes). For a young woman with no comorbid illnesses, adjuvant systemic chemotherapy would clearly be indicated. With regard to management of the putative occult primary, mastectomy offers the advantages of confirming the diagnosis and treating the occult disease. When mastectomy is performed in these circumstances, an occult primary is found in about 70% of cases. Therapeutic options other than mastectomy include empiric breast irradiation.
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