Colorectal Cancer Metastasis to the Thymus Gland: Rare Presentation of Colorectal Cancer as Anterior Mediastinal Mass

Transgenic overexpression of human LY6K in mice suppresses mature T cell development in the thymus

Lymphocyte antigen 6 family member K (LY6K) is upregulated in a number of types of cancer and promotes tumor cell proliferation and metastasis. In addition, LY6K is involved in tamoxifen resistance in breast cancer. However, the in vivo molecular mechanism of LY6K has not yet been investigated. In the present study, transgenic mice overexpressing human LY6K (hLY6K) were generated using the pMAMneo vector, and the effect of LY6K upregulation in vivo was investigated. A total of 4 transgenic mice were generated, and the gene copy number was examined using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). RT-qPCR demonstrated that mRNA of hLY6K was overexpressed in the thymus and spleen of the transgenic mice compared with wild-type mice. Flow cytometric analysis demonstrated that the proportions of B and T cells in the spleen were similar in wild-type and transgenic mice; however, the proportion of thymic mature T cells decreased in the transgenic mice, while there was an increase in the proportion of naïve T cells. These findings suggest that the overexpression of LY6K suppresses T cell development, and that LY6K is a potential therapeutic target for cancer.

Cohort profile: ESPRESSO (Epidemiology Strengthened by histoPathology Reports in Sweden)

The ESPRESSO study constitutes a novel approach to examine the etiology and prognosis of gastrointestinal disease in which histopathology plays a prominent role. Between 2015 and 2017, all pathology departments (n=28) in Sweden were contacted and asked to procure histopathology record data from the gastrointestinal tract (pharynx to anus), liver, gallbladder, and pancreas. For each individual, local histopathology IT personnel retrieved data on personal identity number, date of histopathology, topography (where the biopsy is taken), morphology (biopsy appearance), and where available free text. In total, between 1965 and 2017, histopathology record data were available in 2.1 million unique individuals, but the number of data entries was 6.1 million because more than one biopsy was performed in many of the study participants. Index individuals with histopathology data were matched with up to five controls from the general population. We also identified all first-degree relatives (parents, children, full siblings), and the index individual's first spouse. The total study population consisted of 13.0 million individuals. Data from all the study participants have been linked to Swedish National Healthcare Registers allowing research not only on such aspects as fetal and perinatal conditions and the risk of future gastrointestinal disease but also on the risk of comorbidity and complications (including cancer and death). Furthermore, the ESPRESSO database allows researchers and practitioners to identify diagnoses and disease phenotypes not currently indexed in national registers (including disease precursors). The ESPRESSO database increases the sensitivity and specificity of already-recorded diseases in the national health registers. This paper is an overview of the ESPRESSO database.

Caecal cancer presenting as leg erythema and a lung opacity

Necrotising infection of the lower limb is a rare presentation for colorectal malignancy. We report a case of a perforated caecal adenocarcinoma presenting with right leg erythema, pain and swelling in the presence of a right lower lobe lung opacity. Following initial debridement and washout, CT imaging demonstrated a thickened terminal ileum, caecum and appendix, in keeping with primary malignancy. This fed the right-sided lower limb sepsis tracking down from the medial aspect of the psoas muscle to give rise to the multiloculated collection seen in the adductor compartment. The lung lesion measured 16 mm and was metastatic. The patient was successfully managed with a subtotal colectomy and an end ileostomy. The biopsy confirmed an adenocarcinoma (T4N1M1). We highlight the importance of perforated colonic carcinoma as a leading differential for lower limb abscesses. Suspicions should be raised further if accompanied by rounded opacifications on plain film radiography of the lungs.