Human Papillomavirus (HPV) Detection by Chromogenic In Situ Hybridization (CISH) and p16 Immunohistochemistry (IHC) in Breast Intraductal Papilloma and Breast Carcinoma.

PURPOSE: This study explored human papillomavirus (HPV) amplification in breast benign and malignant lesions by chromogenic in situ hybridization (CISH) and the concordance of p16 expression by immunohistochemistry. PATIENTS AND METHODS: The presence of HPV6/11 and HPV16/18 in 33 cases of intraductal papilloma, 34 cases of ductal carcinoma in situ (DCIS), and 56 cases of invasive breast carcinoma (IBC) was evaluated using matched-background breast parenchyma and breast reduction as control groups. Association with clinicopathologic factors including prognosis was assessed. RESULTS: HPV 6/11 was observed in 0 cases (0%) of breast reduction, one case (3%) of intraductal papilloma, 11 cases (32.4%) of DCIS, and eight cases (14.3%) of IBC. HPV 16/18 was detected in three cases of (9.1%) breast reduction, six cases (18.8%) of intraductal papillomas, 14 cases (41.2%) of DCIS, and 25 cases (44.6%) of IBC. There was no difference in the HPV status between intraductal papilloma and breast reduction. HPV amplification in intraductal papilloma did not associate with developing atypia or carcinoma after long-term follow-up. However, HPV 6/11 and HPV 16/18 amplification was significantly higher in both DCIS and IBC when compared with breast reduction (P < .05). Compared with background breast parenchyma, HPV 16/18 amplification was significantly higher in both DCIS and IBC (P = .003 and P = .013, respectively). No correlation between p16 immunohistochemical staining and either of the HPV CISH testing was found (P > .05). CONCLUSION: HPV infection was detected in both breast lesions and background parenchyma. HPV infection may play a role in the pathogenesis of breast cancer but is not associated with intraductal papilloma. Immunohistochemical stain for p16 is not a good surrogate marker for HPV infection in breast lesions.

Periductal Stromal Sarcoma of the Breast With Liposarcomatous Differentiation: A Case Report With 10-Year Follow-up and Literature Review.

A biphasic tumor with features of benign ductal elements and a malignant stromal component that lacks the architecture of a phylloides tumor represents a diagnostic challenge. A 35-year-old woman presented with a painful mass located in the upper inner quadrant of the right breast. A biopsy revealed histologically that the tumor had a multinodular architecture with malignant spindle cells forming cuffs around multiple open benign ducts. No leaf-like architecture was present. In addition, liposarcomatous differentiation was seen in focal areas. Immunohistochemical staining showed positive for CD34, vimentin and CDK4, and negative for ER, PR, Her2/neu, CD10, CD117, p63, bcl-2, cytokeratin, and MDM2. A diagnosis of periductal stromal sarcoma with liposarcomatous differentiation was established. Following excision with mastectomy and adjuvant chemotherapy, the patient was disease-free for 10 years. To our knowledge, this is the first case report of periductal stromal sarcoma showing liposarcomatous differentiation.