Metastatic carcinoid tumor to the breast: report of two cases and review of the literature

Non-metastatic primary neuroendocrine neoplasms of the breast: a reference cancer center's experience of a heterogenous entity

Background

Primary neuroendocrine neoplasms of the breast (Br-NENs) are rare. The classification has been updated in recent years making interpretation of the data published challenging. It is unclear whether neuroendocrine differentiation is associated with poorer prognosis and what treatment approaches should be applied.

Methods

The database for breast cancer patients treated between 2009 and 2022 at the Maria Sklodowska-Curie National Research Institute of Oncology Branch Krakow was explored to search for Br-NENs. Patients' medical and pathological data were collected and analyzed.

Results

We included 22 females with Br-NEN without metastases at the time of diagnosis. The median age was 64 years (range: 28-88), Of the cases, 18 were hormone receptor positive, all were HER-2 negative, the median Ki67 was 27% (10-100%). The median tumor size at the time of diagnosis was 29.5mm (7-75mm), 9 patients were N-positive. DCIS was present in 5 cases. Only one case was negative for chromogranin and synaptophysin staining, but data were missing for 4 cases. Nine patients received adjuvant chemotherapy, mainly based on anthracyclines and taxanes, while 16 received adjuvant hormonal therapy and 15 received postoperative radiotherapy. Radical surgery was performed in all patients, but two underwent suboptimal tumorectomy. One patient had local recurrence, three experienced metastatic disease, all involving the lungs, but these patients are still alive. The median follow-up was 96 months (8-153). Two patients died, with a follow up time of no recurrence >4 years. Our results were compared to twelve case series collecting clinical data on Br-NENs, with median patient number of 10.5 (range: 3-142).

Conclusion

Br-NENs represent a heterogenous group of diseases, lacking data from prospective studies or clinical trials. There are no established treatment standards tailored for Br-NENs. Our patients' cohort exhibited a favorable prognosis, potentially attributed to lower tumor stage and Ki67 index compared to other reported case series. We suggest that radical surgery and postoperative radiotherapy be administered akin to standard treatment for breast cancer of no special type. ESMO also advocates for this approach in systemic treatment, although we recommend considering platinum-based chemotherapy for patients with poorly differentiated Br-NENs exhibiting high Ki67.

Neuroendocrine Tumor Metastases to the Breast: A Case Report and Review of the Literature

Breast metastases from neuroendocrine neoplasms (NENs) are considered infrequent. We report a case of a patient with ileocecal neuroendocrine tumor (NET) metastases to both breasts, for whom the initial clinical presentation was chronic diarrhea. Breast metastasis was initially suspected by a 68-Gallium DOTANOC positron emission tomography (PET)/CT and was confirmed by histopathology. We also performed a literature review in which we identified 116 cases of NENs metastatic to the breast reported so far. Most cases occurred in older women, were caused by NETs, and had the gastrointestinal tract as the primary site.

Evaluation of Pathologic Prognostic Factors in Neuroendocrine Tumors of the Small Intestine

The precise contributions of histopathologic features in the determination of stage and prognosis in small intestinal neuroendocrine tumors (NETs) are still under debate, particularly as they pertain to primary tumor size, mesenteric tumor deposits (TDs), and number of regional lymph nodes with metastatic disease. This single-institution series reviewed 162 patients with small bowel NETs (84 females, mean age: 60.3±12.0 y). All cases examined (100%) were immunoreactive for both chromogranin A and synaptophysin. Primary tumor size >1 cm (P=0.048; odds ratio [OR]=3.06, 95% confidence interval [CI]: 1.01-9.24) and lymphovascular invasion (P=0.007; OR=4.85, 95% CI: 1.53-15.40) were associated with the presence of lymph node metastasis. Conversely, TDs (P=0.041; OR=2.73, 95% CI: 1.04-7.17) and higher pT stage (P=0.006; OR=4.33, 95% CI: 1.53-12.28) were associated with the presence of distant metastasis (pM). A cutoff of ≥7 positive lymph nodes was associated with pM (P=0.041), and a thusly defined modified pN stage (pNmod) significantly predicted pM (P=0.024), compared with the prototypical pN (cutoff of ≥12 positive lymph nodes), which did not. Over a median follow-up of 35.7 months, higher pNmod (P=0.014; OR=2.15, 95% CI: 1.16-3.96) and pM (P<0.001; OR=11.00, 95% CI: 4.14-29.20) were associated with disease progression. Proportional hazards regression showed that higher pNmod (P=0.020; hazard ratio=1.51, 95% CI: 1.07-2.15) and pM (P<0.001; hazard ratio=5.48, 95% CI: 2.90-10.37) were associated with worse progression-free survival. Finally, Kaplan-Meier survival analysis demonstrated that higher pNmod (P=0.003), pM (P<0.001), and overall stage group (P<0.001) were associated with worse progression-free survival, while higher pM also predicted worse disease-specific survival (P=0.025). These data support requiring either chromogranin or synaptophysin, but not both, for small bowel NET diagnosis, the current inclusion of a 1 cm cutoff in primary tumor size and the presence of TDs in staging guidelines, and would further suggest lowering the cutoff number of positive lymph nodes qualifying for pN2 to 7 (from 12).

A case report on metastatic ileal neuroendocrine neoplasm to the breast masquerading as primary breast cancer: A diagnostic challenge and management dilemma

RATIONALE

Metastatic neuroendocrine neoplasms (NENs) to the breast are very rare entities comprising only 1% to 2% of all metastatic breast tumors. In this article, we describe a case of a neuroendocrine ileal neoplasm metastatic to breast and liver, with breast metastatic tumor to be the initial manifestation of the disease.

PATIENT CONCERNS

We herein report a rare case of a female patient admitted to our department with a palpable painful mass on her left breast.

DIAGNOSIS

The surgical and histological investigation revealed a metastatic neuroendocrine neoplasm to the breast originated from terminal ileum.

INTERVENTIONS

A left lumpectomy, right hemicolectomy, cholecystectomy, left hepatectomy along with liver metastasectomies (V, VI, VIII) plus radiofrequency ablation of lesions to the right liver lobe plus standard lymphadenectomy was performed.

OUTCOMES

Considering the advanced stage of the disease, the patient received an adjuvant therapy of somatostatin analog plus everolimus. Under the guidance of oncological consultation, patients follow-up with CT and MRI scan and clinical re-evaluations in the first 3 and 6 months, substantiates no evidence of recurrence and she presents herself asymptomatic.

LESSONS

An appropriate level of suspicion and selective immunohistochemistry in these cases, particularly where no prior history of a known primary neuroendocrine neoplasm occurs, may help to diagnose a previously undetected neuroendocrine tumor elsewhere in the body and provide guidance for the appropriate treatment selection.

Breast metastases from extramammary malignancies: multimodality imaging aspects

Breast metastases from extramammary cancers are rare and usually related to poor prognosis. The extramammary tumours most frequently exhibiting breast metastases are melanoma, lymphomas, ovarian cancer, lung and neuroendocrine tumours, and sarcomas. Owing to the lack of reliable and specific clinical or radiological signs for the diagnosis of breast metastases, a combination of techniques is needed to differentiate these lesions from primary breast carcinoma or even benign breast lesions. Multiple imaging methods may be used to evaluate these patients, including mammography, ultrasound, MRI, CT and positron emission tomography CT. Clinical and imaging manifestations are varied, depend on the form of dissemination of the disease and may mimic primary benign and malignant breast lesions. Haematologically disseminated metastases often develop as a circumscribed mass, whereas lymphatic dissemination often presents as diffuse breast oedema and skin thickening. Unlike primary carcinomas, breast metastases generally do not have spiculated margins, skin or nipple retraction. Microlobulated or indistinct margins may be present in some cases. Although calcifications are not frequently present in metastatic lesions, they occur more commonly in patients with ovarian cancer. Although rare, secondary malignant neoplasms should be considered in the differential diagnosis of breast lesions, in the appropriate clinical setting. Knowledge of the most common imaging features can help to provide the correct diagnosis and adequate therapeutic planning.