Neuroendocrine neoplasms of the breast: a review of literature

Abstract

Primary neuroendocrine neoplasms (NENs) of the breast are characterized by neuroendocrine architectural and cytological features, which must be supported by immunohistochemical positivity for neuroendocrine markers (such as Chromogranin and Synaptophysin). According to the literature, making a diagnosis of primary neuroendocrine breast cancer always needs to rule out a possible primary neuroendocrine neoplasm from another site. Currently, the latest 2022 version of the WHO of endocrine and neuroendocrine neoplasms has classified breast NENs as well-differentiated neuroendocrine tumours (NETs) and aggressive neuroendocrine carcinomas (NECs), differentiating them from invasive breast cancers of no special type (IBCs-NST). with neuroendocrine features. The current review article describes six cases from our series and a comprehensive review of the literature in the field of NENs of the breast.

Keywords: Histology; Immunohistochemistry; Neuroendocrine neoplasms; Personalized medicine.

Fig. 1

Multiple foci of carcinoma with small cells and neuroendocrine differentiation in breast tissue with numerous foci of LIN1-2 (H&E 200X)

Fig. 2

Details of invasive carcinoma with some foci of LIN2 (H&E 400X)

Fig. 3

Sheets and nests of round or slightly spindle or plasmacytoid cells with round to oval, regular hyperchromatic nuclei with occasional nucleoli, salt and pepper chromatin in a fibrous tissue. Mitoses were scant (H&E 200X)

Fig. 4

Routine mammography: multiple bilateral calcifications and 4 mm hypo-echoic, homogeneous, roundish nodule at EUQ (RIGHT BREAST), with pale margins, with lobular appearance and not-well defined borders

Fig. 5

Foci of neoplastic cells with expression of Chromogranin A (AB, 200X)

Fig. 6

Foci of neoplastic cells with expression of Synaptophysin (AB 400X)

Fig. 7

Foci of neoplastic cells with insular pattern (H&E 400X)

Fig. 8

Details about the mitotic activity in the neoplastic foci (H&E 400X)

Fig. 9

a and b Details of the expression of SSTR2A with different intensity (strong in a, moderate in b) (AB 400X)

Fig. 10

Neoplastic areas with cribriform and papillary architecture (H&E 200X)

Fig. 11

Neoplastic areas with pseudorosette and solid nests (H&E 400X)