Prianka Gajula, MD, Mary R. Schwartz, MD, Ali Raza, MD, Sunil Dacha, MD; Houston Methodist Hospital, Houston, TX
Introduction: Breast cancer is a devastating disease that is the second most common cause of cancer deaths in women worldwide. The American Cancer Society (ACS) states that the five-year survival rate after diagnosis for patients with stage 4 breast cancer is approximately 27%. The most common sites of distant metastases are bone, lung, brain, and liver. Metastatic disease to the pancreas is rare. We present a case of recurrent acute pancreatitis complicated by a pseudocyst, found to be secondary to metastatic breast cancer.
Methods: A 37-year-old female with a past medical history of variably weakly estrogen receptor-positive and triple-negative breast cancer S/P left mastectomy with lymph node dissection, radiation therapy, and chemotherapy presented with left upper quadrant abdominal pain. Clinical and laboratory findings were consistent with pancreatitis. The etiology was initially deemed to be secondary to alcohol use. Further imaging demonstrated a fluid collection in the pancreatic tail without a mass lesion. The patient was referred to us by her oncologist for a second opinion. Due to a clinical suspicion that her pancreatitis was not related to alcohol use, EUS was performed. A 13 mm x 11 mm hypoechoic mass was identified in the pancreatic body. An EUS-guided fine needle biopsy was performed. The pathologic interpretation was of high-grade adenocarcinoma, compatible with metastatic triple-negative breast carcinoma. The patient qualified for a chemotherapy drug trial based on the diagnosis of metastatic breast cancer, and following this, the pancreatic fluid collection resolved. To date, she has not had a recurrence of the pseudocyst on surveillance imaging. Discussion: Metastatic disease to the pancreas is rare, and breast cancer accounts for less than 5% of cases. These lesions usually present as solid masses, rather than presenting as recurrent acute pancreatitis and pseudocysts as in our patient. In patients with aggressive cancers and recurrent acute pancreatitis with no overt etiology, EUS should be considered for the evaluation of occult mass lesions. Overall, triple-negative breast cancer has a poor prognosis. In such cases, the goal of treatment is not only prolonged survival but also improved quality of life. Chemotherapy is the first-line treatment, as surgical outcomes have been controversial. In conclusion, in a patient with a history of malignancy, new clinical or imaging findings should raise concern for metastatic disease.
Figure 1: Magnetic resonance cholangiopancreatography imaging of 6 cm distal peripancreatic fluid collection, consistent with a pseudocyst.
Figure 2: EUS images of 13 mm x 11 mm hypoechoic mass was identified in the pancreatic body (A) and a 60 mm x 50 mm pseudocyst seen in the tail of the pancreas, communicating with the pancreatic duct (B).
Figure 3: Images A and B are H&E stained sections of the cell block made from the FNA. Numerous pleomorphic cells are shown. Images C and D demonstrate a positive immunostain for SOX-10, a nuclear transcription factor that has been reported as a relatively more sensitive marker for TNBC than GATA35, a transcription factor expressed in the majority of breast cancers. This confirms that the pathology was consistent with metastatic breast cancer.
Disclosures: Prianka Gajula indicated no relevant financial relationships. Mary Schwartz indicated no relevant financial relationships. Ali Raza indicated no relevant financial relationships. Sunil Dacha indicated no relevant financial relationships.