Mismatch Repair Deficiency as a Predictive and Prognostic Biomarker in Endometrial Cancer: A Review on Immunohistochemistry Staining Patterns and Clinical Implications.

Among the four endometrial cancer (EC) TCGA molecular groups, the MSI/hypermutated group represents an important percentage of tumors (30%), including different histotypes, and generally confers an intermediate prognosis for affected women, also providing new immunotherapeutic strategies. Immunohistochemistry for MMR proteins (MLH1, MSH2, MSH6 and PMS2) has become the optimal diagnostic MSI surrogate worldwide. This review aims to provide state-of-the-art knowledge on MMR deficiency/MSI in EC and to clarify the pathological assessment, interpretation pitfalls and reporting of MMR status.

Prognostic Value of Mandard's Tumor Regression Grade (TRG) in Post Chemo-Radiotherapy Cervical Cancer.

In locally advanced cervical cancer (LACC), definitive chemo-radiotherapy is the standard treatment, but chemo-radiotherapy followed by surgery could be an alternative choice in selected patients. We enrolled 244 patients affected by LACC and treated with CT-RT followed by surgery in order to assess the prognostic role of the histological response using the Mandard scoring system. Results: A complete pathological response (TRG 0) was observed in 118 patients (48.4%), rare residual cancer cells (TRG2) were found in 49 cases (20.1%), increased number of cancer cells but fibrosis still predominating (TRG3) in 35 cases (14.3%), and 42 (17.2%) were classified as non-responders (TRG4-5). TRG was significantly associated with both OS (p < 0.001) and PFS (p < 0.001). The survival curves highlighted two main prognostic groups: TRG1-TRG2 and TRG3-TRG4-5. Main responders (TRG1-2) showed a 92% 5-year overall survival (5y-OS) and a 75% 5-year disease free survival (5y-DFS). Minor or no responders showed a 48% 5y-OS and a 39% 5y-DFS. The two-tiered TRG was independently associated with both DFS and OS in Cox regression analysis. Conclusion. We showed that Mandard TRG is an independent prognostic factor in post-CT/RT LACC, with potential benefits in defining post-treatment adjuvant therapy.

Primary Mucinous Cystadenocarcinoma of the Breast Intermixed with Pleomorphic Invasive Lobular Carcinoma: The First Report of This Rare Association.

Primary mucinous cystadenocarcinoma (MCA) is a rare breast carcinoma subtype showing overlapping histopathological features with mucinous cystadenocarcinoma of the ovary and pancreas. Current literature data suggest a favorable prognosis of breast MCAs despite its immunoprofile usually revealing lack of expression of estrogen receptor, progesterone receptor and HER-2 and high Ki67. As far as we know, only 36 cases have been reported in the literature to date. Its ambiguous morpho-phenotypic profile makes histological diagnosis very challenging. It must be distinguished from typical mucin-producing breast carcinomas and, above all, metastases from the same histotype in other sites (ovary, pancreas, appendix). Herein, we report the case of a primary breast MCA occurring in a 41-year-old female with peculiar histological features.

High-grade serous ovarian carcinoma with a sertoliform pattern associated with BRCA mutation: a clinicopathological and molecular analysis.

Herein, we report a clinicopathological and molecular analysis of a case of tubo-ovarian high-grade serous carcinoma (HGSC) with a sertoliform pattern. A 45-year-old woman underwent surgery due to an advanced bilateral adnexal carcinoma with peritoneal and appendiceal metastases. Histological examination revealed an HGSC exhibiting a distinct sertoliform component. Such component showed diffuse PAX8, p53 (mutation-type), and p16 (block-type) expression, increased vimentin and decreased WT1 expression compared to the conventional HGSC component, membrane ß-catenin positivity, heterogeneous estrogen, and progesterone positivity, and retained PTEN and mismatch repair expression and negativity for GATA3, TTF1, inhibin, calretinin, CD10, CDX2, chromogranin, and synaptophysin. Molecular analysis showed a germline BRCA2 mutation; no mutations were detected in POLE, POLD1, MLH1, MSH2, MSH6, PMS2, APC, CTNNB1, MUTYH, and EPCAM. In conclusion, a sertoliform pattern can be part of the morphological spectrum of BRCA-related HGSC.

What Can Trigger Spontaneous Regression of Breast Cancer?

BACKGROUND: Spontaneous regression of tumors is a rare phenomenon in which cancer volume is reduced or, alternatively, a tumor completely disappears in the absence of any pharmacological treatment. This phenomenon has previously been described in several tumors, such as neuroblastomas, testicular malignancies, renal cell carcinomas, melanomas, and lymphomas. Spontaneous remission has also been documented in breast cancer; however, it represents an extremely rare and poorly understood phenomenon, with only a few reported cases in the literature. METHODS: We herein report two cases of breast cancer that showed spontaneous tumor regression in the surgical specimen after a pathologically confirmed diagnosis of invasive breast cancer in core needle biopsy samples. RESULTS: Macroscopically, both the surgical samples revealed a whitish, fibrous area with a rubbery consistency. On histological examination, diffuse fibrous tissue, hemosiderin deposition, and chronic inflammation were observed. The first case showed the complete disappearance of the tumor, whereas the second case showed just a small (3 mm), residual nest of neoplastic cells. CONCLUSIONS: Although spontaneous regression of breast cancer is a rare event, it is important to know that it might happen. It is also of great importance to try to better explain, over time, its underlying mechanism. This knowledge could help us to further develop cancer prevention methods and predict the clinical course of these kinds of neoplasms.

Recent Advances in Cervical Cancer Management: A Review on Novel Prognostic Factors in Primary and Recurrent Tumors.

BACKGROUND: Several pathological parameters, including tumor size, depth of stromal invasion, lympho-vascular space invasion and lymph node status, have been proposed as prognostic predictors in cervical cancer. However, given the high mortality and recurrence rate of cervical cancer, novel parameters that are able to provide additional prognostic information are needed in order to allow a better prognostic stratification of cervical cancer patients. METHODS: A search was conducted on PubMed to identify relevant literature data regarding prognostic factors in cervical cancer. The key words "cervical cancer", "prognostic factors", "pathology", and "outcome" were used. RESULTS: The novel pathological grading system based on tumor budding and cell nest size appeared the most relevant prognostic factor in primary neoplasms. Moreover, other potentially useful prognostic factors were tumor size, depth of stromal invasion, lympho-vascular space invasion, perineural invasion, tumor-free distance and tumor-infiltrating lymphocytes. Prognostic factors related to advanced-stage cervical cancer, including lymph-nodes status, endometrial and cervical involvement as well as distant metastases, were also taken into consideration. CONCLUSIONS: According to our findings, tumor budding and cell nest size grading system, depth of stromal invasion, lympho-vascular space invasion, perineural invasion, tumor-free distance and tumor-infiltrating lymphocytes appeared the most relevant factors included in the pathology report.

One biopsy, two tumors: A case report of collision tumor consisting in breast and endometrioid carcinoma detected on bioptic sample of peritoneal carcinomatosis.

Collision tumors are rare and very few cases were described in which collision was revealed in a metastatic lesion. Herein we report a case of woman with a peritoneal carcinomatosis underwent to bioptic procedure in correspondence of a nodule of Douglas peritoneum with clinical suspect of ovarian/uterine origin. Histologic examination revealed two different colliding epithelial neoplasms: an endometrioid carcinoma and a ductal breast carcinoma, the latter not suspected at the time of biopsy. Morphology and immunohistochemistry, in particular GATA3 and PAX8, defined clearly the two different colliding carcinomas.

Pilomatrix-like High-Grade Endometrioid Carcinoma of the Ovary: Case Report, Literature Review, and Differential Diagnosis.

Pilomatrix-like high-grade endometrioid carcinoma (PiMHEC) has recently been described as an aggressive variant of endometrial carcinoma. Herein, we described a case of ovarian PiMHEC, comparing it to endometrial PiMHEC and assessing previously published cases of putative ovarian PiMHEC. A 65-year-old woman underwent hysterectomy for an ovarian tumor characterized by solid nests of basaloid cells with prominent ghost cell keratinization. Immunohistochemistry showed nuclear ß-catenin and CDX2 expression and loss of estrogen and progesterone receptors and PAX8. These features were consistently observed in all previously published cases and may represent diagnostic criteria of PiMHEC. Other frequent features were geographic necrosis and a low-grade endometrioid component. CK7, neuroendocrine, and basal/squamous markers were inconsistently expressed. All cases with available follow-up showed poor prognosis. PiMHEC should be distinguished from mimickers, such as high-grade endometrioid carcinoma with geographic necrosis, low-grade endometrioid carcinoma with ghost cell keratinization, and undifferentiated/dedifferentiated carcinoma. In conclusion, PiMHEC can also occur in the ovary and shows several consistent clinical, morphological, and immunophenotypical features. These features support that PiMHEC is a distinct entity requiring an aggressive management.

A large series of hyalinizing trabecular tumors: Cytomorphology and ancillary techniques on fine needle aspiration.

BACKGROUND: Hyalinizing trabecular tumors (HTTs) are rare, essentially benign, follicular cell-derived thyroid neoplasms characterized by a trabecular growth pattern and nuclear pseudoinclusions. Their cytological findings are misleading, because these tumors are often misinterpreted on fine needle aspirate cytology as malignant lesions, such as papillary thyroid cancer and/or medullary thyroid cancer, leading to unnecessary total thyroidectomy. The aim of this study was to analyze the cytomorphological features and application of ancillary techniques in a series of HTTs. METHODS: Of 26 histological cases of HTT collected from September 2001 to December 2018, 18 cases had concomitant cytopathology. Cytological cases were processed with liquid-based cytology (LBC). Immunocytochemistry for HBME-1 and galectine-3 as well as molecular testing for BRAFV600E mutation were performed on both LBC and histological specimens. RESULTS: The 18 lesions with fine needle aspirate cytology ranged in size from 5 to 45 mm. Cytological diagnoses included: 1 benign lesion favoring goiter (5.5%), 4 atypia of undetermined significance (22.2%), 6 follicular neoplasms (33.3%), 5 suspicious for malignancy favoring papillary thyroid cancer (28%), and 2 malignant (11%). Hence, 89% HTT had a negative concordant immunopanel, and they were 100% wild-type BRAFV600E . CONCLUSION: The majority of our HTTs (83.3%) were diagnosed in the indeterminate Bethesda categories, suggesting that their cytomorphological features pose issues for reaching a conclusive cytological diagnosis. The ancillary test results in our series support the fact that HTT is a benign neoplasm.