Marked Decrease in CA 19-9 Level Belies Rapidly Progressive Lymphangitic Carcinomatosis in a Case of Metastatic Pancreatic Cancer.

Background: The CA 19-9 tumor marker is commonly used alongside imaging to trend chemotherapy response in patients with pancreatic ductal adenocarcinoma. Presentation: We describe an unusual clinical case of metastatic pancreatic cancer who achieved a marked decline in CA 19-9 but paradoxically developed widespread pulmonary lymphangitic carcinomatosis leading to rapid clinical decline and death. Conclusions: This case highlights the limitations of using the CA 19-9 tumor marker in isolation.

The eye of the beholder: orbital metastases from midgut neuroendocrine tumors, a two institution experience.

BACKGROUND: Metastases to the orbit occur rarely in midgut neuroendocrine tumor (NET) patients with only 20 cases reported to date. Patients typically present with bilateral involvement of the recti muscles and experience symptoms such as diplopia, proptosis, and decreased vision. Although orbital MRI remains the gold standard for imaging orbital disease, many orbital lesions are now detected on somatostatin-receptor (SSTR) based imaging such as 68Ga-DOTATATE PET-CT. CASE PRESENTATIONS: Patient 1 is a 72 year-old female with a well-differentiated G3 ileal NET who was incidentally diagnosed with orbital metastases during a hospitalization for pre-septal cellulitis in 2018. Her disease has been controlled with capecitabine rather than local therapy. Patient 2 is a 68 year-old male with a G2 ileal NET who was diagnosed with orbital involvement after developing left peri-orbital swelling in 2017. He was found to have bilateral rectus muscle involvement and was treated with image-guided radiation therapy (IGRT) to both orbits and achieved disease control. Patient 3 is a 63 year-old female with a well-differentiated G3 ileal NET who was incidentally diagnosed with bilateral orbital masses in her recti after undergoing a 68Ga-DOTATATE PET-CT in 2015. She was asymptomatic initially however has now developed diplopia. She will be starting 177Lu-DOTATATE peptide radionuclide receptor therapy (PRRT) shortly. Patient 4 is a 72 year-old male with a grade 2 ileal NET who was incidentally diagnosed with a left lateral rectus metastasis in 2007. This was monitored via surveillance MRI until it began to grow and became symptomatic in 2015. The patient received stereotactic radiation to the site and has been asymptomatic since. Patient 5 is a 61 year-old female with a grade 2 ileal NET who developed progressive diplopia in 2016. Bilateral orbital metastases were noted on orbital MRI and she completed IGRT to the sites shortly thereafter. In the setting of continued growth of the masses she was switched to chemotherapy with capecitabine which has controlled her orbital disease. CONCLUSIONS: NETs can metastasize to the orbits. Orbital disease now often is detected on SSTR-based imaging rather than orbital MRI; when found, it changes treatment approach and surveillance for patients.

Hidden Figures: Occult Intra-Cardiac Metastases in Asymptomatic Neuroendocrine Tumor Patients.

Carcinoid heart disease is a devastating paraneoplastic consequence of unchecked hormone production from neuroendocrine tumors (NET) and often results in right-sided heart failure. While it occurs frequently in NET patients with carcinoid syndrome, cardiac metastases occur much less often and are usually only incidentally found. Gallium-68 dotatate (ga-68) is an imaging tracer which binds to somatostatin receptor 2 with greater avidity than Indium-111, the tracer used commonly in octreotide scans. Ga-68 PET/CT is the most sensitive study for detecting occult NET metastases and has emerged as the current imaging gold standard. We describe two cases from Vanderbilt University Medical Center and Stanford University Medical Center where asymptomatic patients with well-differentiated midgut NET were diagnosed with intra-cardiac metastases using ga-68 PET/CT. Management of these patients was altered based on the findings as they underwent extensive cardiac evaluation and initiation of therapy with octreotide. Fortunately, they have not suffered life-threatening cardiac complications seen in some NET patients, from other published series, such as bradycardia, heart block, syncope and arrhythmias. These possibilities suggest early cardiology evaluation and consideration of other therapies beyond octreotide, such as surgery or PRRT, may be essential for all NET patients found to have intra-cardiac metastases.