Primary Neuroendocrine Carcinoma of the Breast with Clinical Features of Inflammatory Breast Carcinoma: A Case Report and Literature Review

Abstract

Primary neuroendocrine carcinoma of the breast (NECB) is a very rare type of invasive breast carcinoma. Most NECBs appear on breast imaging as solid masses of varied shapes and margins, and have worse clinical outcomes than does invasive ductal carcinoma, not otherwise specified. However, there have been no reports to date regarding NECB with features of inflammatory breast carcinoma. Here, we describe the clinical, radiol-ogic, and pathologic findings of the first reported case of primary NECB presenting as inflammatory breast carcinoma. The patient complained of diffuse right breast enlargement and erythema. Mammography identified severe breast edema and axillary lymphadenopathy. Ultrasound detected an irregular, angular, hypoechoic mass with dermal lymphatic dilatation. On magnetic resonance imaging, the mass had rim enhancement and the entire right breast showed heterogeneous enhancement with malignant kinetic features. Pathology identified the mass as a primary NECB with positive for synaptophysin, CD56, estrogen and progesterone receptors.

Primary Neuroendocrine Carcinoma of the Breast: A Case Report and Review of the Literature

“…They usually present as a palpable mass in the breast [12] [13]. There has been only one report to date of a primary neuroendocrine carcinoma of the breast with clinical features of inflammatory breast carcinoma [14], such with our patient.…”

“…NEBC appears hypodense on mammography, as round or irregularly shaped masses with variable margins either speculated, indistinct, circumscribed, or obscured [14]. On ultrasonography, such tumors may present as either morphologically irregular solid lesions or lesions with a cystic component, with ill defined margins and increased vascularization [11].…”

“…However, unlike common breast carcinomas, NEBC may appear as sharply circumscribed masses with no associated microcalcifications on mammography mimicking a benign tumor [2]. On MRI, they appear as irregular masses with rim enhancement and malignant kinetic characteristics, and early rapid and delayed washout enhancement [14].…”

“…In Lee's report [14], various regimens (six cycles of cicplatin and etoposide, six cycles of docetaxel and three cycles of eribulin) were attempted for advanced stage inflammatory NEBC, however the tumor showed poor response and the patient developed metastatic lesions. Other case reports showed effectiveness of platinum based chemotherapy and endocrine therapy [19] [20].…”

Dramatic response to cyclin D–dependent kinase 4/6 inhibitor in refractory poorly differentiated neuroendocrine carcinoma of the breast

“…A similar study that used this treatment plan and then followed up with tamoxifen did not achieve tumor regression, similar to our case. 6 Another reported case of neuroendocrine carcinoma of the breast expressing estrogen receptor, progesterone receptor, and Her2 achieved remission using docetaxel, trastuzumab, and carboplatin. 7 Because most neuroendocrine breast tumors are estrogen receptor and progesterone receptor positive, endocrine-based therapy may be an effective treatment strategy.…”