A clinicopathologic analysis of 31 patients with solid papillary carcinoma of breast

Abstract

Objective To study the clinicopathologic features, immunophenotype, diagnosis and differential diagnosis of solid papillary carcinoma (SPC) of breast. Methods A retrospective study was performed to analyse the clinicopathologic features and immunophenotype of 31 cases of SPC with or without invasion. The cytokeratins (CK), myoepithelial markers, neuroendocrine markers, proliferation marker Ki-67, estrogen receptor (ER), progesterone receptor (PR), HER2, ect were detected by immunohistochemical staining, and HER2 was detected by FISH. All patients were followed up. Results All the patients were females with a mean age of (67.0±12.5) years. The presenting symptom was a painless mass with or without nipple discharge. In 19 cases who had undergone axillar lymph node dissection, only one metastasis was observed. General observation showed that tumors had substantive and nodular lesions, accompanied by cyst formation. Microscopy examination showed that tumors had swell and substantive nodules with only fine fiber vascular axis, and lacked obvious nipples and screen structure. The cells were lack of atypia,adhesive in cells nest. 20 patients were accompanied by mucus secretion. Immunohistochemical study showed that the tumor cells expressed CK8/18, ER, PR, but didn't express basal cell CK5/6, 34β12. The positive rates of CK5/6, 34β12, p63 were 3.23 % (1/31), 9.68 % (3/31), 6.45 % (2/31) in the myoepithelial layers of axis of papillary, and were 19.25 % (6/31), 38.71 % (12/31), 16.13 % (5/31) in peripheral cell nests and tumors, respectively. The positive rates of CgA, Syn, NSE, Cd56 were 83.87 % (26/31), 87.10 % (27/31), 93.55 % (29/31), 90.32 % (28/31), respectively. The staining of HER2 oncoprotein was negative mostly, and the FISH detection outcome of 15 cases were all negative. The average positive index of Ki-67 was 4.12 %. 28 cases (90.23 %) received follow-up, only 1 patient died, and the rest patients were without tumor recurrence or metastasis. Conclusions SPC of breast, a rare pathologic type, usually occurs in old females. The diagnosis depends on pathological characteristics and its unique immune phenotypic characteristics. SPC of breast has close relationship with mucinous carcinoma and neuroendocrine carcinoma,with a relatively inert biological behavior. Key words: Solid papillary carcinoma of breast; Clinicopathologic; Immunophenotype; In situ hybridization, fluorescence; Prognosis