[Serrated polyps and their association with synchronous advanced colorectal neoplasia]. / Pólipos serrados y su asociación con neoplasia avanzada de colon.

INTRODUCTION: Large serrated polyps (SP), proximal SP, SP with dysplasia and the presence of multiple sessile serrated adenomas/polyps (SSA/P), which we refer to as SP with increased risk of metachronous lesions (SPIRML), have been associated with an increased risk of advanced colon lesions on follow-up. It is unclear, however, whether SPIRML are also associated with an increased risk of synchronous advanced colorectal neoplasia (ACN). AIM: The aim of this study was to estimate the prevalence of SPIRML and to evaluate the association between SPIRML and synchronous ACN. METHODS: A cross-sectional population-based study in all patients (1,538) with histological diagnosis of SP obtained from colonoscopies, sigmoidoscopies and colonic surgery performed in Navarra Health Service hospitals (Spain) in 2011. Demographic parameters and synchronous colonic lesions (adenomas, advanced adenomas [AA] and ACN) were analyzed. RESULTS: One fourth of the sample (384 patients) presented SPIRML. These were older patients, with a slight predominance of women, and with no differences in body mass index (BMI) compared to patients without SPIRML. In the univariate analysis, patients with SPIRML showed an increased risk of adenoma, AA and ACN. In the multivariate analysis, the SPIRML group had a higher risk of synchronous AA and ACN (odds ratio [OR]: 2.38 [1.77-3.21] and OR: 2.29 [1.72-3.05], respectively); in the case of ACN, this risk was statistically significant in both locations (proximal or distal), with OR slightly higher for the proximal location. Different subtypes of SPIRML had a higher risk of AA and synchronous NA. CONCLUSION: SPIRML were common in patients with SP, and their presence was associated with an increased risk of synchronous ACN.

[Prevalence of altered mismatch repair protein nuclear expression detected by immunohistochemistry on adenomas with high-grade dysplasia and features associated with this risk in a population-based study]. / Prevalencia de alteración de expresión nuclear de proteínas reparadoras con inmunohistoquímica sobre adenomas con displasia de alto grado y características asociadas a dicho riesgo en un estudio de base poblacional.

INTRODUCTION: Alteration of mismatch repair system protein expression detected by immunohistochemistry (IHQ) in tumoural tissue is a useful technique for Lynch Syndrome (LS) screening. A recent review proposes LS screening through immunohistochemical study not only in all diagnosed cases of colorectal cancer (CRC) but also in advanced adenomas, especially in young patients. OBJECTIVE: To assess the prevalence of altered IHQ carried out in all adenomas with high-grade dysplasia (HGD) diagnosed in our community in 2011, as well as the variables associated with this alteration. METHODS: We included all the cases of adenomatous polyps with HGD diagnosed in the three public pathology laboratories of Navarre during 2011 and performed a statistical study to assess the association between different patient and lesion characteristics and altered IHQ results. RESULTS: A total of 213 colonic adenomas with HGD were diagnosed, and 26 (12.2%) cases were excluded from the final analysis (2 known LS, 22 without IHQ study and 2 with inconclusive IHQ studies). The final number of adenomas included was 187. Pathologic results were found in 10 cases (5.35%)-6 cases in MLH1 and PMS2, 2 cases in PMS2, 1 case in MSH6 and 1 case in MSH2 and MSH6. The factors showing a statistically significant association with the presence of abnormal proteins were the synchronous presence of CRC, the presence of only one advanced adenoma, proximal location of HGD and age <50 years. CONCLUSIONS: The percentage of pathologic nuclear expression found in IHQ is high. Consequently, screening of all diagnosed HGD could be indicated, especially in young patients, with a single AA and proximal HGD.

Scars Run Deep: Problematic Morphology and Immunoprofile of Scars in Renal Oncocytomas.

In some instances, the central scar of renal oncocytoma can demonstrate entrapped cells with unusual morphology and aberrant immunoprofile creating potential diagnostic confusion. Herein, 100 renal oncocytomas containing scars with embedded epithelial cells were identified from 6 institutions, including nephrectomies (64% partial, 36% radical) of similar laterality (left = 51%) and sex distribution (male = 56%), with patient ages ranging from 38 to 86 years (mean = 64.3years) and tumor sizes ranging from 2 to 16 cm (mean = 5.3 cm). Immunohistochemistry was performed on all tumors for KRT7, KIT, vimentin, and CA9 with staining intensity and extensity separately analyzed. Of 4 architectural patterns of cells within the scar, 60% showed tubular pattern. Of 4 cytologies within the scar, flat/elongated (49%) and cuboidal cells (40%) predominated. Within the scar, 62% showed eosinophilic cytoplasm, with 38% showing both cleared and eosinophilic cytoplasm; notably, 79% showed higher grade nuclei than typical oncocytes. A subset of scar cells showed mucinous-like basophilic secretions (19%). Compared to background renal oncocytoma, tumor cells within the scar were more often positive for vimentin, KRT7, and CA9 and more frequently negativity for KIT. Specifically, of the notable "aberrant" immunoprofiles, 79% showed KRT7 positivity/KIT negativity/vimentin positive, 84% showed vimentin positivity/CA9 positivity, and 78% showed KIT negativity/vimentin positivity/CA9 positivity. While encountering scars within renal oncocytomas is not uncommon, what is not well appreciated is the unique morphology and immunohistochemistry of tumor cells within the scar. Comparing tumor morphology and immunoprofile of the scar to the background oncocytoma is helpful to avoid interpretative confusion.

Fibrosing cholestatic hepatitis following cytotoxic chemotherapy for small-cell lung cancer.

Fibrosing cholestatic hepatitis (FCH) is a variant of viral hepatitis reported in hepatitis B virus or hepatitis C virus infected liver, renal or bone transplantation recipients and in leukemia and lymphoma patients after conventional cytotoxic chemotherapy. FCH constitutes a well-described form of fulminant hepatitis having extensive fibrosis and severe cholestasis as its most characteristic pathological findings. Here, we report a case of a 49-year-old patient diagnosed with small-cell lung cancer who developed this condition following conventional chemotherapy-induced immunosuppression. This is the first reported case in the literature of FCH after conventional chemotherapy for a solid tumor. In addition to a detailed report of the case, a physiopathological examination of this potentially life-threatening condition and its treatment options are discussed.

Primary mixed squamous carcinoma and osteosarcoma (carcinosarcomas) of the lung have a CGH mapping similar to primitive squamous carcinomas and osteosarcomas.

Carcinosarcomas are malignant tumors with a mixture of carcinomatous and differentiated sarcomatous elements. We investigate the morphology, immunohistochemistry, and comparative genomic hybridization analysis of 3 mixed squamous carcinoma and osteosarcoma of the lung. All patients were male and their ages were 72, 43, and 58 years. The sizes of the neoplasms were 7, 5, and 5 cm in maximum diameter, respectively. Two patients died of the disease 9 and 14 months after surgery; and one is alive 6 months later. By light microscopy, all cases had both squamous and osteosarcomatous structures. Immunohistochemistry was positive for AE3AE1, p63, 34 E12, CAM 5.2 (2/3 cases), CK-7 (2/3 cases), epithelial membrane antigen, E-cadherin, p53, and carcinogenic embryonic antigen in carcinomatous areas, and for vimentin and CD-68 in sarcomatous component. Areas of transition positive for both cytokeratins and vimentin were seen in all cases. A total of 55 copy number changes were detected with a median of 18 abnormalities per case: 48 gains, 6 losses, and 1 high-level amplification. Chromosome alterations in osteosarcomatous areas were similar to those found in lung metastatic osteosarcoma, comparable to those found in carcinomatous areas and to lung squamous carcinomas. Coincidences between carcinomatous areas and osteosarcomatous zones were found as gains in chromosomes 1q, 3q, 5p, 8q, and 12p. These findings provide arguments that favor a common origin for both types of cells, supported by the mixture of cells, the existence of undifferentiated cells positive to both cytokeratin and vimentin markers, and the CGH overlaps of chromosomal gains between carcinomatous and sarcomatous areas.