Diagnostic Dilemma: A 67 year old woman with cancer in an abdominal lymph node: is this a recurrence of a previous cancer? (BR01-02)

Patient History:

A 67 year old woman had breast cancer in 1992 and treated by a mastectomy. Fifteen years later, she is found to have a enlarged pericaval (abdominal) lymph node. A fine needle aspiration pathology of the lymph node reveals cancer, but the site of origin cannot be determined.

Original Diagnosis:

In 1992 breast cancer of the right breast was diagnosed as infiltrating lobular carcinoma. The histology was poorly differentiated. The current aspiration tests on the lymph node tests positive for malignant cells, also with poorly differentiated histology. Cannot confirm if this is a recurrence of the previous breast cancer.

RedPath Diagnosis:

The cancer in the lymph node is a metastasis of the original breast cancer from 1992. Both cancers share seven identical allelic imbalance mutations on 3p, 5q, 9p, 17p, 17q, and 22q, establishing a common tumor origin. In addition, the 1p mutation in the lymph node demonstrates a continued mutational evolution expected for a metastasis.

Generic sample of PathFinderTG® quantitative test results. NOTE: A diagnostic interpretation of the quantitative test results is provided by the RedPath Pathologist.
Click here for test result explanation

Clinical Impact:

The PathFinderTG analysis unequivocally linked the original breast tumor from 1992 to the current 2007 tumor in the abdominal lymph node, a recurrence after 15 years. The ability to definitively diagnosis this cancer as a metastatic breast cancer eliminated further scans and tests in trying to detect a new primary. More importantly, it will allow the patient’s doctor to choose the most appropriate cancer treatment, e.g. multiple agent chemotherapy versus surgery and additional studies.