Additive Benefit of Confocal Laser Endomicroscopy and Micro-Forceps Needle Biopsy in the Evaluation of a Mucinous Cystic Neoplasm

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A 76 F presented with 6 months of abdominal pain and CT images of a pancreatic cyst. Multiple inconclusive EUS FNA procedures were performed at an outside hospital. We used a linear array echoendoscope to visualize the pancreatic parenchyma at our facility and then passed a confocal probe (AQ Flex) and micro-forceps (Moray needle) through a 19g needle (Cook Medical) into the cystic lesion. Initial on-site cytopathology evaluation of cyst fluid suggested atypical cells. Cyst fluid analysis subsequently demonstrated elevated CEA 8537 ng/mL and amylase 1788 U/L. The AQ flex probe was advanced along the cyst wall for CLE and the pattern demonstrated a single thick band suggestive of a mucinous cystic neoplasm (MCN). The micro forceps were advanced to that region and biopsy the cyst wall. Touch prep evaluation of the forceps biopsy and cell block analysis were positive for mucinous lesion. The patient received Cipro 400 mg IV during the procedure then discharged on 3-day oral course. She developed intense abdominal pain with syncope before outpatient resection. An outside hospital CT showed the pancreatic cyst with moderate amount of peripancreatic fluid with an intralesional linear density, possibly a stent or remnant of a biopsy apparatus. A distal pancreatectomy, splenectomy, left nephrectomy and left adrenalectomy was performed and revealed MCN with dysplasia measuring 8 cm with no invasive carcinoma. Margins were negative for tumor and no malignancy was identified in the lymph node sampled. Also obtained was the foreign body. At 2 week follow up, patient was doing well with no abdominal pain. We examined a pancreatic cyst case using EUS-FNA, CLE, micro-forceps needle biopsy and surgical pathology. This unique case report demonstrates the additive efficacy of EUS-FNA, CLE and micro-forceps biopsy for diagnosis. The case also describes a complication of retained foreign material within the cyst cavity; 19 g needle from the EUS device. Future prospective studies evaluating the added benefit of pancreatic cyst confocal and micro-biopsy are warranted. Additionally, it is important to note that many products utilized in clinical practice have not been designed for that specific purpose. The passage of the CLE probe and moray needle through the 19g needle at an appropriate echoendoscope position for cyst sampling may have resulted in breakage of the needle. Our institution now performs evaluations on devices after use as part of a post-procedure checklist.

1382_A.tif Figure 1: CT of pancreas tail cystic lesion.

1382_B.tif Figure 2: The dysplastic images show the mucinous cystic neoplasm with multilayered cells and nuclei that are coming off the basement membrane. There is also some nuclear pleomorphism as well. This is in contrast to the non-dysplastic image attached which shows a single layer of uniform cells. Note in both instances the ovarian type stroma underneath the epithelial layer, characteristic of a mucinous cystic neoplasm

1382_C.tif Figure 3: FNA needle in the surgically resected pancreatic cyst specimen.