Morphological and molecular changes of oestrogen receptor-positive breast cancer following bridging endocrine therapy: a United Kingdom multicentre study.

AIMS: Standard neoadjuvant endocrine therapy (NAET) is used for 6-9 months to downstage hormone-receptor-positive breast cancer. Bridging ET was introduced during the COVID-19 pandemic to delay surgical intervention. There are no data in the literature on the effect of short course therapy on tumour response. We aimed to analyse the effect of bridging ET and validate the previously proposed neoadjuvant ET pathological reporting criteria. METHODS AND RESULTS: This was a multicentre cohort of 256 patients who received bridging ET between March and October 2020. Assessment of paired pre- and post-NAET hormone receptors and HER2 and posttherapy Ki67 expression was done. The median duration of NAET was 45 days. In all, 86% of cases achieved partial pathological response and 9% showed minimal residual disease. Histological response to ET was observed from as early as day 6 posttherapy. Central scarring was noted in 32.8% of cases and lymphocytic infiltrate was seen in 43.4% of cases. Significant changes associated with the duration of ET were observed in tumour grade (21%), with downgrading identified in 12% of tumours (P < 0.001), progesterone receptor (PR) expression with switch to PR-negative status in 26% of cases (P < 0.001), and HER2 status with a switch from HER2-low to HER2-negative status in 32% of cases (P < 0.001). The median patient survival was 475 days, with an overall survival rate of 99.6%. CONCLUSIONS: Changes characteristic of tumour regression and significant changes in PR and HER2 occurred following a short course of NAET. The findings support biomarker testing on pretreatment core biopsies and retesting following therapy.

Pathological Changes Following Neoadjuvant Endocrine Therapy (NAET): A Multicentre Study of 391 Breast Cancers.

Oestrogen receptor (ER)-positive breast cancer (BC) is generally well responsive to endocrine therapy. Neoadjuvant endocrine therapy (NAET) is increasingly being used for downstaging ER-positive tumours. This study aims to analyse the effect of NAET on a well-characterised cohort of ER-positive BC with particular emphasis on receptor expression. This is a retrospective United Kingdom (UK) multicentre study of 391 patients who received NAET between October 2012 and October 2020. Detailed analyses of the paired pre- and post-NAET morphological changes and hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) expression were performed. The median duration of NAET was 86 days, with median survival and overall survival rates of 380 days and 93.4%, respectively. A total of 90.3% of cases achieved a pathological partial response, with a significantly higher rate of response in the HER2-low cancers. Following NAET, BC displayed some pathological changes involving the tumour stroma including central scarring and an increase in tumour infiltrating lymphocytes (TILs) and tumour cell morphology. Significant changes associated with the duration of NAET were observed in tumour grade (30.6% of cases), with downgrading identified in 19.3% of tumours (p < 0.001). The conversion of ER status from positive to low or negative was insignificant. The conversion of progesterone receptor (PR) and HER2 status to negative status was observed in 31.3% and 38.1% of cases, respectively (p < 0.001). HER2-low breast cancer decreased from 63% to 37% following NAET in the paired samples. Significant morphological and biomarker changes involving PR and HER2 expression occurred following NAET. The findings support biomarker testing on pre-treatment core biopsies and post-treatment residual carcinoma.

Reappraisal of SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1/INI-1 deficient tumor: Report of two cases.

SWI/SNF-related matrix-associated actin-dependent regulator of chromatin subfamily B member 1 is a tumor suppressor gene located at chromosome 22q11.2. In the past decade, a major stride has been taken for decoding the molecular genesis of various tumors which has resulted in the addition of newer tumors harboring loss of this gene.

Immunohistochemical subtyping of diffuse large B-cell lymphoma into germinal center B-cell and activated B-cell subtype, along with correlation of the subtypes with extranodal involvement, serum lactate dehydrogenase, and positron emission tomography scan-based response assessment to chemotherapy.

Context: Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphoma in Indian population and is divided into the prognostically important subtypes, germinal center B-cell (GCB) and activated B-cell-like (ABC), using immunohistochemistry-based algorithm. Aim: The present study aims to evaluate the influence of immunohistochemical derived DLBCL subtype, GCB or ABC on prognostically significant variables - extranodal involvement and serum lactate dehydrogenase (LDH) level at presentation, and response to chemotherapy assessed on pre- and posttreatment fluorodeoxyglucose-positron emission tomography study. Settings and Design: This was a retro-prospective, 2-year observational study at a tertiary health-care center, New Delhi. Subjects and Methods: The study population includes a total 236 cases of DLBCL. According to the Hans algorithm, DLBCL cases were allocated to the GCB and ABC subgroups. Statistical Analysis Used: For comparison of mean values, independent t-test and analysis of variance were used. For this purpose, we used SPSS 20.0 software. P < 0.05 was considered as statistically significant. Results: Ninety-eight patients (41.5%) had GCB immunophenotype and 138 patients (58.5%) were ABC. A significant difference was observed between mean baseline level of LDH between GCB and ABC subtypes (P < 0.05). The proportion of cases with extranodal involvement was comparatively higher in ABC subtype (P < 0.05). Association between response to chemotherapy with DLBCL immunophenotypes was found to be highly significant (P < 0.00). The response rates were much better in GCB subtype. Conclusions: The mean baseline level of LDH is significantly higher in ABC subtype. The proportion of cases with extranodal involvement was comparatively higher in ABC and shows poor response to chemotherapy as compared to GCB. Baseline LDH level was found to be important prognostic marker in the DLBCL.

Extranodal Follicular dendritic cell sarcoma presenting as a rectal polyp: An entity overlooked by its differentials.

Extranodal follicular dendritic cell sarcoma (ENFDCS) is a rare hematolymphoid tumor, masquerading as soft tissue sarcoma on initial histological examination. So, for its confirmation, the application of immunohistochemistry (IHC) is of paramount importance. Over the years there has been a major shift in the demography of follicular dendritic cell sarcoma (FDCS), with a rise in the number of extranodal cases. Herein we report a case of ENFDCS presenting as a rectal polyp, who had a history of intermittent bleeding per rectum and passage of fleshy mass while defecation. As these tumors share an overlapping morphology with other spindle cell tumors and can occur at unpredictable locations, they pose a diagnostic challenge, especially for young pathologists.

Periductal stromal sarcoma of breast with lipoblast-like cells: a case report with review of literature.

The specialized mesenchyme of the breast is the seat of neoplasms with distinct morphology, though with considerable overlap due to the ever increasing number of variants. This article seeks to describe the morphologic features of one such rare neoplasm. A 35-year-old female patient presented with a breast lump that was subsequently excised. Morphological assessment and immunohistochemistry were performed and a diagnosis of periductal stromal sarcoma with lipoblast-like cells (pseudolipoblasts), was made. Being an unusual finding in a rare entity of intermediate grade, it has to be considered, before rendering a diagnosis of a malignant, higher-grade neoplasm.

An unusual case of hepatic lymphoma with multiple epithelial malignancies.

Primary hepatic mucosa-associated lymphoid tissue lymphoma (MALToma) is a rare entity. Its coexistence with other malignancies is even rarer. Only few case reports of its association with other malignancies mostly gastric and colon cancer have been published. We report a case of primary MALToma of liver in an unusual setting of dual solid malignancy.

Primary retroperitoneal mucinous cystadenocarcinoma in a male patient.

Primary retroperitoneal mucinous neoplasms are extremely rare tumors. Less than sixty cases have been reported in international literature until date, with striking female predominance. We report a case of primary mucinous cystadenocarcinoma of the retroperitoneum in a 51-year-old male presenting with nonspecific abdominal complaints. This case is being highlighted for its rare occurrence in a male patient.

Primary neuroendocrine carcinoma of the vagina with coexistent atypical vaginal adenosis: a rare entity.

Primary neuroendocrine carcinoma of the female genital tract is a rare entity with aggressive clinical behavior and a poor prognosis. This kind of malignancy arising in the vagina is extremely rare. We report a case of primary neuroendocrine carcinoma of vagina arising in a setting of atypical vaginal adenosis.

Clear cell adenocarcinoma of the male urethral tract.

We present a rare case of clear cell adenocarcinoma of the male bulbomembranous urethra. Mostly these tumors have been described in the female urethral tract with its possible origin from mullerian remnants, wolffian remnants or paraurethral glands. Histologically, these tumors have typically tubulocystic pattern comprising of hobnailed cells with clear glycogenated cytoplasm along with well-defined cytoplasmic membranes. This case is being presented due to its rarity, aggressive behavior and to discuss, trauma as its possible etiological factor.

MRI evaluation of the contralateral breast in patients with recently diagnosed breast cancer.

INTRODUCTION: Contralateral breast cancer can be synchronous and/or metachronous in patients with cancer of one breast. Detection of a synchronous breast cancer may affect patient management. Dynamic contrast-enhanced MRI of the breast (DCE-MRI) is a sensitive technique for detecting contralateral lesions occult on the other imaging modalities in women already diagnosed with cancer of one breast. AIM: The aim was to assess the incidence of mammographically occult synchronous contralateral breast cancer in patients undergoing MRI mammography for the evaluation of a malignant breast lesion. MATERIALS AND METHODS: A total of 294 patients with recently diagnosed breast cancer who underwent MRI of the breast were evaluated for lesions in the opposite breast. RESULTS: The incidence of synchronous contralateral malignancy detected by preoperative MRI mammography done for evaluation of extent of disease was 4.1%. CONCLUSION: Preoperative breast MRI may detect clinically and mammographically occult synchronous contralateral cancer, and can help the patient avoid an additional second surgery or a second course of chemotherapy later; also, as theoretically these lesions are smaller, there may be a survival benefit as well.

Extrauterine adenomyoma with uterus like features: a rare entity presenting 17 years post hysterectomy.

We report a case of a 47-year-old female (posthysterectomy) with bleeding per vaginum. Imaging studies showed a large abdomino-pelvic mass diagnosed as extrauterine adenomyoma with uterus-like features. This pathological entity is extremely uncommon with only few case reports available in the reported literature. This case is being highlighted for its rarity and to discuss the possible theories for origin of this uncommon condition.

Peri-ampullary collision tumor - high grade neuroendocrine carcinoma and signet ring cell carcinoma: a case report and review of literature.

We report a case of 50-year-old male with obstructive jaundice diagnosed as peri-ampullary collision tumor comprising of large cell neuroendocrine carcinoma and signet ring cell carcinoma. The association of neuroendocrine (usually carcinoids) and adenocarcinoma is extremely uncommon with only few case reports available in the reported literature.

Myoepithelial carcinoma arising in an adenomyoepithelioma of the breast: a case report of a rare entity.

Adenomyoepithelioma of the breast is a rare tumor. Malignant change arising in this lesion is infrequent and only a few cases have been reported. We discuss a case of a 56-year-old female presenting with a firm breast mass, which was interpreted as myoepithelial carcinoma arising in a background of adenomyoepithelioma, based on morphological and immunohistochemical studies. This case is being highlighted for its rarity and distinct morphological spectrum.