title: Neuroendocrine Differentiation in Breast Cancer: Clinicopathological Significance of Bcl-2 Positive Solid Papillary Carcinoma.
abstract: Solid papillary carcinoma (SPC) is considered a rare malignant breast tumor. Maluf and Koerner first reported this disease entity as a special type of ductal carcinoma in situ with several characteristic histopathological features, including low-grade cellular atypia, intracellular or extracellular mucin deposition, and solid papillary growth pattern, as well as neuroendocrine differentiation. The present paper describes a case of SPC with bcl-2 expression, which is known as a marker for malignancy of neuroendocrine tumors. Interestingly, despite bcl-2 expression being a poor prognostic indicator of neuroendocrine tumors, the patient with this tumor has achieved long-term survival (approximately 6 years) at the time of writing this report. Because previous investigators reported that bcl-2 expression might play a role in the inhibition of the development of breast cancer, we suggest that bcl-2 expression might reflect a good prognosis in patients with SPC, rather than being a poor prognostic indicator, as it is in several types of neuroendocrine tumor. However, to confirm this hypothesis, further investigation is required.
authors.affiliation: Department of Pathology, Kanagawa Cancer Center, 2-3-2 Nakao, Asahi-Ku, Yokohama, Kanagawa 241-8515, Japan.
authors.forename: Yoichiro
authors.identifier: 0000-0002-7079-4454
authors.initials: Y
authors.lastname: Okubo
authors.affiliation: Department of Internal Medicine, Okubo Internal Medicine/Surgery Clinic, 1282 Ohaza, Oita, Oita Prefecture 870-1151, Japan.
authors.forename: Takuji
authors.initials: T
authors.lastname: Okubo
authors.affiliation: Department of Surgery, Okubo Internal Medicine/Surgery Clinic, 1282 Ohaza, Oita, Oita Prefecture 870-1151, Japan.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Okubo
authors.affiliation: Department of Pathology, Chiba Cytopathological Center, 5-27-8 Nishifuna, Funabashi, Chiba 273-0031, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Ishiwatari