Tissue Selection for PD-L1 Testing in Triple Negative Breast Cancer (TNBC).

Atezolizumab in combination with nab-paclitaxel has been introduced for the treatment of locally advanced or recurrent triple negative breast cancer (TNBC). Patient selection relies on the use of immunohistochemistry using a specific monoclonal PD-L1 antibody (clone SP142) in a tightly controlled companion diagnostic test (CDx) with a defined interpretative algorithm. Currently there are no standardized recommendations for selecting the optimal tissue to be tested and there is limited data to support decision making, raising the possibility that tissue selection may bias test results. We compared PD-L1 SP142 assessment in a collection of 73 TNBC cases with matched core biopsies and excision samples. There was good correlation between PD-L1-positive core biopsy and subsequent excision, but we found considerable discrepancy between PD-L1 negative core biopsy and matched excision, with a third of cases found negative on core biopsies converting to positive upon examination of the excision tissue. In view of these findings, we developed a workflow for the clinical testing of TNBC for PD-L1 and implemented it in a central referral laboratory. We present audit data from the clinical PD-L1 testing relating to 2 years of activities, indicating that implementation of this workflow results in positivity rates in our population of TNBC similar to those of IMpassion130 clinical trial. We also developed an online atlas with a precise numerical annotation to aid pathologists in the interpretation of PD-L1 scoring in TNBC.

Colorectal Cancer Stratification in the Routine Clinical Pathway: A District General Hospital Experience.

Colorectal cancer (CRC) has many subtypes with different prognoses and response to treatment. Patients must be characterized to access the most appropriate treatment and improve outcomes. An increasing number of biomarkers are required for characterization but are not in routine use. We investigated whether CRC can be stratified routinely within a small district general hospital to inform clinical decision making at local multidisciplinary team meeting/tumor board level. We evaluated mismatch repair (MMR) and EGFR signaling pathways using predominantly in-house immunohistochemical (IHC) tests (MSH2, MSH6, MLH1, PMS2, BRAF-V600E, Her2, PTEN, cMET) as well as send away PCR/NGS tests (NRAS, KRAS, and BRAF). We demonstrated that many of the tests required for personalized treatment of CRC can be done locally and timely. Send away tests need to be requested shortly after cut-up and this needs to be firmly established in the tissue pathways for the results to be considered at multidisciplinary team meeting/tumor board. We have shown that MMR IHC combined with BRAFV600E IHC is practical and easy to perform in a small district general hospital, has full concordance with DNA-based tests and satisfies the latest NICE requirements for the identification of potential Lynch syndrome patients. We provide a framework for the interpretation and presentation of test results. It is a practical classification that clinical pathologists can use to communicate effectively with the clinical team. It is broadly based on molecular subtyping, firmly focused on treatment decisions and dependent on the panel of molecular tests currently available.

Cutaneous microcystic/reticular schwannoma: case report and literature review of an exceedingly rare entity with an unusual presentation.

Conventional schwannoma represents a benign peripheral nerve sheath tumor derived from Schwann cells, which usually arises in the fourth or fifth decade of life, in the subcutaneous tissue of the distal extremities, or in the head and neck region of adult patients, with no gender predilection. In addition to the classic type, at least 11 different histopathological subtypes have been described and unawareness of these uncommon histopathological entities may lead to diagnostic pitfalls and risk of mistreatment. Recently described in the scientific literature, microcystic/reticular schwannoma is still relatively unknown to both surgeons and pathologists. The purpose of this paper is to highlight its existence by describing an additional case that occurred in the retroauricular area, and to further characterize its clinical, histopathological and immunohistochemical features. We reviewed the literature and compared the current case with others that have been documented thus far, discussing all possible differential diagnoses.

Keratoacanthoma centrifugum marginatum: an unusual clinical and histopathological diagnostic pitfall.

Keratoacanthoma centrifugum marginatum (KCM) is a very rare variant of keratoacanthoma characterized by progressive peripheral growth accompanied by central healing. The tumor has the peculiar ability to involute spontaneously. A careful differential diagnostic with other skin carcinomas or hyperkeratotic lesions is required in order to ensure appropriate clinical management. We report a case of KCM in a 62-year-old man presenting with a solitary, large exophytic, sessile tumor located on the ventral side of the right lower leg, which developed over the course of one year from an initial erythematous papule. The patient presented history of local trauma. To our knowledge, this is the second report in the scientific literature supporting a possible traumatic etiology. Due to its rarity and lack of distinctive histopathological features, KCM poses a difficult diagnostic challenge. Therefore, the importance of an accurate histopathological examination and extensive use of ancillary studies for differential diagnosis is emphasized.

Apoptosis in cutaneous melanomas.

Cutaneous melanomas has become one of the most discussed and studied tumor because its particular immunologic development but also its increasing rate worldwide in the last decades. Even thought many patients are diagnosed at an early stage, the death rate continues to rise due to the increasing incidence of more advanced lesions. The aim of this study is to detect apoptosis in 30 cases of cutaneous melanomas using the in situ end-labeling technique (TUNEL) who quantify apoptotic cell death at single cell level and tissues.

Cutaneous metastases carcinoma. Case report and pathological considerations.

Diagnostic of cutaneous metastases is relatively rare; this is important because sometimes may be the first manifestation of an undiscovered internal malignancy. Usually dissemination may take place through the lymphatics or the blood stream. The case of a patient, female, which has on the inferior 1/3 part of the abdominal wall skin a multinodular tumor mass, which evolves from about three months ago and accompanying by lymphoedema of the legs, is presented.

Postmenopausal choriocarcinoma: a case report.

Postmenopausal uterine choriocarcinoma is very rare and benefits of curative chemotherapy. We present here the case of 62-year-old women with uterine bleeding. Emergency surgery revealed a uterine tumor and histopathology findings were consistent with choriocarcinoma. Immunohistochemistry tests confirmed betahCG and cytokeratin expression by malignant cells, thus establishing the positive diagnosis.