The rare entity of bilateral and unilateral neuroendocrine metastases to the breast: a case series and literature review

The rare case of synchronous bilateral breast metastasis from a lung neuroendocrine tumor (small cell lung carcinoma): a case report and literature review

BACKGROUND

Breast metastasis from small cell neuroendocrine carcinoma (SNEC) is very rare. In the present report, we describe a case of a female patient who was initially diagnosed with triple negative primary bilateral breast cancer, but during systemic examination, the diagnosis was bilateral breast metastasis from SNEC.

CASE PRESENTATION

A 62-year-old woman with no history of smoking presented to the Department of General Medicine with left-sided chest pain, and computed tomography revealed masses in both breasts and left pleural thickening that was further confirmed by mammography and ultrasound of the breasts. A needle biopsy was performed, and triple negative primary bilateral breast cancer was diagnosed. Because progastrin-releasing peptide (ProGRP) 37,300 pg/ml (normal range, 0-81.0 pg/ml) and neuron-specific enolase 35.0 ng/ml (normal range, 0-16.3 ng/ml) levels were elevated, thoracoscopic biopsy was performed, and SNEC was diagnosed. Pathological examinations showed that the bilateral breast masses were also positive for immunohistochemical staining of chromogranin A, synaptophysin, and CD56, leading to a diagnosis of bilateral breast metastasis of neuroendocrine tumor.

CONCLUSION

Although very rare, the possibility of breast metastasis should be considered when malignancy is suspected in other organs.

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.

Radiological and Histological Clues in the Diagnosis of Solitary and Synchronous Breast Metastasis From Small Cell Lung Carcinoma

Breast metastases from small cell lung carcinoma (SCLC) are extremely rare. Although reports of breast metastases from SCLC exist, only three studies have reported solitary and synchronous breast metastases. Herein, we present a case of SCLC with solitary and synchronous breast metastases. This unusual case highlights the importance of the combined use of radiological and immunohistochemical features to accurately distinguish solitary metastatic SCLC from primary breast carcinoma or metastatic carcinoma of other types of lung cancer. It also emphasizes the importance of the differences between solitary metastatic SCLC and primary breast carcinoma or metastatic carcinoma of other types of lung cancer for the respective prognoses and development of appropriate therapeutic plans.

Primary Breast Neuroendocrine Tumors: An Analysis of the National Cancer Database

BACKGROUND

Primary breast neuroendocrine tumors (BNETs) represent < 1% of breast cancers. Diagnosing BNETs can be challenging, and a limited amount of cohort data currently exists in literature. We aimed to describe primary BNET characteristics, treatment modalities, and survival outcomes through the National Cancer Database (NCDB).

METHODS

A retrospective cohort analysis was performed using the NCDB from 2004 to 2017. BNET cases were compared with patients with invasive ductal carcinoma (IDC). A matched IDC cohort was created by matching patient age, race, and disease stage. Kaplan-Meier analysis was performed, and hazard ratios (HR) were calculated through the bootstrap sampling method.

RESULTS

A total of 1389 BNET and 1,967,401 IDC cases were identified. When compared with IDC patients, BNET patients were older, had more comorbidities, and were more often male (p < 0.01). BNETs were larger, higher grade, and more frequently hormone receptor negative (p < 0.01). While BNET patients were treated with surgery and radiotherapy (p < 0.01) less often compared with IDC patients, they presented at later disease stage (p < 0.001) and received systemic treatment more frequently (53.5% vs. 40%, p < 0.01). Patients with BNET had increased mortality compared with the matched IDC cohort: stage 1 HR 1.8, stage 2 HR 2.0, stage 3 HR 1.8, and stage 4 HR 1.5 (p < 0.001 for all).

CONCLUSION

Patients with BNET tend to present at higher clinical stages, are more frequently hormone receptor negative, and have inferior overall survival compared with patients with IDC. Further treatment strategies and studies are needed to elucidate optimal therapies to maximize patient outcomes.

Bilateral breast metastases as the first manifestation of an occult pancreatic neuroendocrine tumor

Breast metastases are uncommon findings compared to primary breast cancer and in particular bilateral secondary breast lesions from neuroendocrine tumor (NET)s are extremely rare with just less over 13 cases described in literature. We reported herewith the case of a 54-year-old woman who presented to our Breast Unit after noticing multiple, mobile, bilateral breast lumps. Imaging studies confirmed the presence of multiple, circumscribed, bilateral breast masses with slightly spiculated margins, classified as suspicious for malignancy (BI-RADS 4). A tru-cut biopsy was carried out on the largest lesion of each side and histopathologic and immunohistochemistry examination was consistent with metastases from pancreatic neuroendocrine tumor (PNET). Total-body CT revealed the presence of a mass located in the pancreatic body - tail with associated abdominal lymphadenopathies and multiple secondary nodules in bilateral breast and in the liver. Stage IV disease was diagnosed, patient did not undergo surgery and started LAR – octreotide therapy. Although rare, breast metastases from NETs represent an important diagnostic challenge for practitioners because of the difficulty to differentiate from a primary breast carcinoma or even from benign breast lesions. Clinicians should be aware of the possibility of bilateral breast metastases in differential diagnosis of breast lesions in order to ensure the correct diagnosis and the most appropriate management of these patients.

Bilateral breast metastases from small cell lung carcinoma: Case report and review of the literature

Differentiation of primary versus secondary breast cancer can be difficult, with the relative rarity of the latter representing a diagnostic challenge. Here, we present a case of small cell lung cancer with synchronous bilateral breast metastases in a 52-year-old female. There are less than 5 other cases of small cell lung cancer with bilateral breast metastases reported in the literature to date. The breast metastases represented the first clinical and imaging manifestation of malignancy in our case. We present the patient's disease course including multi-modal imaging, histopathologic analysis, and clinical management. We aim to highlight the entity of secondary breast cancer and how multidisciplinary collaboration can help arrive at the diagnosis, which is critical for prognosis and treatment planning in this patient population.