MKSAP Quiz: Management of a metastatic neuroendocrine tumor
A 48-year-old woman is evaluated following the diagnosis of a metastatic neuroendocrine tumor. Two weeks ago, she underwent ultrasonography for biliary colic, which unexpectedly showed multiple hepatic lesions. Following tests, a physical exam, and lab studies, what is the most appropriate management?
A 48-year-old woman is evaluated following the diagnosis of a metastatic neuroendocrine tumor. Two weeks ago, she underwent ultrasonography for biliary colic, which unexpectedly showed multiple hepatic lesions. Gallstones were not present. A subsequent contrast-enhanced CT scan of the abdomen demonstrated multiple hypodense lesions in the liver consistent with metastatic disease. A needle biopsy of a liver lesion showed a well-differentiated, low-grade neuroendocrine tumor with only very rare mitotic figures. Medical history is otherwise unremarkable. The patient feels well without any symptoms, and she takes no medications.
On physical examination, vital signs are normal. Abdominal examination reveals a palpable, firm liver edge 5 cm below the right costal margin.
Results of laboratory studies show a minor elevation of transaminases and alkaline phosphatase.
Which of the following is the most appropriate management?
A. Hepatic artery embolization
B. Hormonal therapy with a somatostatin analogue
C. Peptide-receptor radiotherapy
D. Repeat imaging in 3 months
E. Systemic chemotherapy
MKSAP Answer and Critique
The correct answer is D. Repeat imaging in 3 months. This content is available to MKSAP 19 subscribers as Question 61 in the Oncology section. More information about MKSAP is available online.
The most appropriate management is repeat imaging in 3 months (Option D). This patient has an incidental finding of a well-differentiated, low-grade, gastrointestinal neuroendocrine tumor with multiple metastases to the liver. These tumors are often asymptomatic and indolent, and asymptomatic patients may do well with minimal growth and no symptoms for years without intervention. As such, there is no urgency to intervene, and it is beneficial to evaluate the pace of the disease before making a decision regarding whether to treat. Follow-up examination and imaging at approximately a 3-month interval is appropriate in asymptomatic patients with relatively modest-volume, asymptomatic disease. Approximately one third to one half of metastatic gastrointestinal neuroendocrine tumors will elaborate serotonin, a hormone that causes “carcinoid syndrome” with diarrhea and/or facial flushing; however, most patients have a hormonally nonfunctional tumor and so will not require treatment for these symptoms. In patients who have stable disease at the 3-month scan, further monitoring with serial imaging at 3- to 6-month intervals is appropriate.
Hepatic arterial embolization (Option A) is a procedure that may be helpful in shrinking liver metastases or reducing hormonal output from functional tumors. It may be appropriate in a patient with progressive, bulky, or symptomatic disease.
For moderate progression, a somatostatin analogue (Option B) can be used. This treatment often slows disease progression, although actual tumor shrinkage is rare. Somatostatin analogues are highly effective in controlling hormonal disease and should be given if hormone-related symptoms are present.
Peptide-receptor radiotherapy (Option C) is a treatment that is appropriate for patients with either a substantial disease burden or clinically significant growth under observation but would not be warranted in an asymptomatic patient with small-volume disease.
Cytotoxic chemotherapy (Option E) is of limited utility in patients with well-differentiated neuroendocrine tumors.
Key Points
- Well-differentiated neuroendocrine tumors are indolent, frequently discovered incidentally, and often initially only require observation and serial imaging.
- Somatostatin analogues are highly effective in controlling hormonal manifestations of gastrointestinal neuroendocrine tumors and should be given if hormone-related symptoms are present.