Can pathological reports of rectal cancer provide national quality indicators?

BACKGROUND: Rectal cancer care has become increasingly complex and requires accurate information. The pathology report is a vital tool for accessing information to gauge a patient's prognosis and to guide treatment decisions. The aim of this study was to assess the quality of histopathological reporting and surgery for rectal cancer in New Zealand using defined quality indicators. METHODS: This is a retrospective audit of pathological reports of all resected rectal cancer pathology reports submitted to the New Zealand Cancer Registry (NZCR) in 2015. The quality of reporting was assessed using specified criteria: synoptic report, adequate lymph node retrieval, reporting of circumferential resection margin (CRM) and mesorectal excision quality. Surgical outcomes were sphincter preservation rate, CRM clearance and complete mesorectal excision. RESULTS: A total of 803 patients with rectal cancer were reported to the NZCR in 2015, 505 underwent proctectomy. A total of 89.5% of reports were structured, 81.8% reported mesorectal excision quality and 86.7% reported CRM status. Adequate lymph node retrieval was obtained in 65.1%, complete mesorectal excision in 84.6% and positive CRM in 6.2% of cases. Quality varied between laboratories and district health boards. High-volume laboratories had higher quality reporting. Surgeon volume and training was related to adequate lymph node retrieval but not CRM clearance nor mesorectal excision quality. CONCLUSION: High-quality pathological reporting is associated with the use of synoptic reporting templates. Surgical outcomes for rectal cancer in New Zealand, especially the low rate of CRM involvement, compare favourably with international audits.

[Value of endorectal ultasound in predicting the circumferential resection margin and maximum tumor thickness of T3 rectal cancer].

OBJECTIVE: To evaluate the accuracy of endorectal ultrasound (ERUS) in predicting the circumferential resection margin (CRM) and maximum tumor thickness (MTT) of in T3 rectal cancer. METHODS: Clinicl data of 53 patients with pT3 rectal cancer admitted to the Department of General Surgery in the Peking Union Medical College Hospital from June 2011 to January 2014 were retrospectively analyzed. CRM and MTT measured by ERUS were compared with corresponding pathologic measurements to assess the accuracy of ERUS diagnosis. RESULTS: ERUS correctly predicted CRM status in 52 patients (98.1%, 52/53), whose sensitivity was 100%, specificity was 97.8%, positive predictive value was 85.7%, and negative predictive value was 100%. ERUS correctly predicted MTT status in 51 patients (96.2%, 51/53), whose sensitivity was 100%, specificity was 95.5%, positive predictive value was 66.6%, and negative predictive value was 100%. In the Bland and Altman plot, the agreement between ERUS and pathology was good. CONCLUSION: Endorectal ultrasonography can accurately diagnose CRM and MTT, which can satisfy the clinical need for preoperative staging of rectal cancer.

Primary perivascular epithelioid cell tumor in the rectum: a case report and review of the literature.

Perivascular epithelioid cell tumor (PEComa) is a rare collection of tumors arising in a wide array of anatomic locations. It is characterized by the presence of a peculiar population of myomelanocytic marker-positive perivascular epithelioid cells, and is commonly detected in the uterus. The colorectal area is an uncommon site for primary PEComa. In this study, we describe a 17-year-old patient presenting with a rectal polyp. Histologically, the tumor consisted of sheets of round to polygonal epithelioid cells with clear and granular cytoplasm, and a prominent capillary network. Some of the tumor cells were positive for Fontana-Masson staining. Immunohistochemically, the tumor cells were positive for HMB-45, and were negative for cytokeratin, vimentin, S-100 protein, actin, desmin, EMA, CD34, and c-kit. After finding melanosomes or premelanosomes at the ultrastructural level, the diagnosis of PEComa was made. Although PEComa arising within the intestinal tract is unusual and clinically unexpected, PEComa should be considered in the differential diagnosis of rectal polypoid lesions.

Pure micropapillary rectal carcinoma with CK7 and CK20 coexpression and loss of CDX2 reactivity / Carcinoma micropapilar rectal puro con coexpresión de CK7 y CK20 y pérdida de reactividad CDX2

The micropapillary carcinoma is regarded as an aggressive variant of adenocarcinoma in any location. Histologically is characterized by papillary cell clusters surrounded by clear spaces. The reported proportion of micropapillary carcinoma component to the entire tumor ranged from 5 to 80 percent and no pure cases has been reported. There are near of 130 cases reported to date in colorectum. We experienced a patient with a pure micropapillary carcinoma showing coexpression of CK7, CK20, and absence of CDX2, which had an aggressive neoplasm with extense perineural, vascular and lymphatic invasion also extensive nodal metastasis. The presence of a micropapillary carcinoma in the colorectum seemed to be closely related with nodal metastasis, similar to the case for micropapillary carcinomas in other organs. Therefore, if a micropapillary component is identified in a tumor, particularly in a biopsy specimen, even if the pre-operative diagnosis is a pedunculated early colorectal cancer, should be carefully consider the extent of surgical resection due to the high potential for nodal metastasis.

El carcinoma micropapilar es considerado como una variante agresiva del cáncer en cualquier localización. Histológicamente se caracteriza por grupos de células papilares rodeada de espacios libres. Se informó que la proporción del componente carcinoma micropapilar en la totalidad de un tumor varió entre 5 por ciento a 80 por ciento y no se han reportado casos puros. Existen cerca de 130 casos reportados hasta la fecha en colon y recto. Se describe el caso de un paciente con un carcinoma micropapilar puro que muestra coexpresión de CK7, CK20, y la ausencia de CDX2, que tenía un tumor agresivo con extensa invasión perineural, vascular y linfática además de metástasis nodular extensa. La presencia de un carcinoma micropapilar en la región colorrectal parece estar estrechamente relacionada con metástasis nodular, similar al caso del carcinomas micropapilar en otros órganos. Por lo tanto, si un componente micropapilar se identifica en un tumor, sobre todo en una muestra de biopsia, incluso si el diagnóstico pre-operatorio es un cáncer colorrectal temprano pediculado, se debe considerar cuidadosamente la extensión de la resección quirúrgica debido a la alta probabilidad de metástasis nodular.

Comparative characterization of mouse rectum CMT93-I and -II cells by expression of claudin isoforms and tight junction morphology and function.

Recent studies suggest that the morphological and physiological properties of tight junctions (TJs) are determined by the combination and mixing ratios of claudin isoforms. In this study, we tried to characterize mouse cell lines by expression of claudin isoforms to use for studying epithelial TJs by overexpression or suppression of claudin(s) in the cells and found that claudin-2 was expressed in a few mouse rectum carcinoma cells, CMT93 cells. We have isolated CMT93-I and -II cells from CMT93 cells by immunohistochemical screening for the presence or absence of claudin-2 expression. Immunofluorescence and RT-PCR analyses showed that expression of claudin-4, -6, -7 and -12 was detected in both cell lines, but claudin-2 was only expressed in CMT93-II cells. There were no differences in paracellular permeability between CMT93-I and -II cells examined by 4 kDa FITC-dextran and fluorescein sodium, or in the number of TJ strands examined by freeze-fracture electron microscopy. However, the transepithelial electrical resistance (TER) of CMT93-I cells was approximately 6.5 times higher than that of CMT93-II cells, suggesting that expression of claudin-2 may be related to decreased TER. Comparative examinations of CMT93-I and -II cells provide a clue how the combination and mixing ratios of claudin isoforms regulate the paracellular permeability.

Primary small cell malignant melanoma of the rectum: case report of a very rare tumor.

Rectal/anorectal malignant melanomas are highly aggressive tumors with a poor prognosis and low 5-year survival rate. They are also very rare. Of the well-known histological variants of malignant melanoma, the small cell subtype is also very uncommon; consequently, small cell anorectal malignant melanoma is an exceedingly rare occurrence. In this article, the authors provide a detailed clinicopathological description of small cell malignant melanoma of the rectum, documenting clinical, histological, immunohistochemical, and ultrastructural features, to add to the sparse references on this tumor in the literature. The patient was a 53-year-old woman with a mass 2 cm from the anus, which was surgically removed. In histological sections, the tumor was a small cell malignant melanoma, with a tumor cell diameter of 7.6+/-1.0 microm, and a range of 5.5-10.7 microm (N = 100). Tumor cells were positive for S-100 protein and HMB-45 and contained sparse but unambiguous type II melanosomes. This article is one of the few detailed clinicopathological documentations of a small cell malignant melanoma of the rectum (anorectum) and the first to have the diagnosis confirmed ultrastructurally by the identification of melanosomes. The present case adds to the 3 mainly or entirely small cell anorectal malignant melanomas described in the literature. There are also at least 12 other cases with less well-defined numbers of small tumor cells or with small cells admixed with other cell morphologies. Documentation of these unusual morphological variants is important for identifying any distinctive outcome they might exhibit compared with conventional malignant melanoma.

Morphological observation of tumor infiltrating immunocytes in human rectal cancer.

AIM: To investigate the morphological characterization of tumor infiltrating dendritic cells (TIDCs) and tumor infiltrating lymphocytes (TILs) in human rectal cancer. METHODS: Light and electron microscopy as well as immunohistochemistry were used to observe the distributive and morphological changes of TIDCs and TILs. RESULTS: TIDCs were mainly located in tumor-surrounding tissue. The number of TIDCs in the earlier stage was higher than that in the later stage (P<0.01). TILs were mainly seen in adjacent tissue of cancers and tumor-surrounding tissue. There were more TILs in the earlier stage than that in the later stage (P<0.01). Under electron microscope, TIDCs were irregular in shape and exhibited many dendritic protrusions. It is not obvious that cancer cells perforated the basement membrane and TILs were arranged along the basement membrane in the earlier stage. In the later stage, it is explicit that cancer cells perforated the basement membrane and surrounded by TILs. There were contacts among TIDCs, TILs and tumor cell. One TIDCs contacted one or several TILs which clustered around TIDCs. Glycogen granules were seen between TIDCs and TILs. CONCLUSION: The number of TIDCs and TILs is related with tumor progression There exist close relationships among TIDCs, TILs and tumor cell.

Rectal adenocarcinoma with oncocytic features: possible relationship with preoperative chemoradiotherapy.

BACKGROUND: The introduction of preoperative chemoradiation into the treatment protocol of rectal adenocarcinomas has affected the microscopical morphology in subsequent resection specimens. The constellation of histopathological changes is varied and well documented. AIM: To describe oncocytic change in rectal cancers that have been treated with chemoradiation before surgery. METHODS: 7 of 54 patients with rectal cancer were identified with a history of chemoradiation, specifically directed to the rectal tumours in fractions of 4500-5000 cGy of radiation and 5-fluorouracil. The rectal tumours in five of these seven patients were composed of oncocytes that constituted 30-80% of the cancers. The patients were three men and two women aged 65-73 years, all with T3 N0 tumours. The intervals between chemoradiation and resection varied from 3 to 12 weeks. RESULTS: The tumour cells conformed to oncocytes morphologically (large size with abundant, granular eosinophilic cytoplasm, vesicular nuclei and prominent acidophilic nucleoli), immunohistochemically (positive for carcinoembryonic antigen, cytokeratin 20 and caudal type homeo box transcription factor 2, but negative for both chromogranin and synaptophysin) and ultrastructurally (large cells showing tight junctions, cytoplasmic engorgement by mitochondria and absence of neurosecretory granules). CONCLUSIONS: The changes in these cells differ from those described previously in endocrine cells encountered in pretreated rectal cancers. Oncocytic change in this particular clinical context occurs as a reflection of cytotoxic damage or cellular hypoxia induced by chemoradiation resulting in degeneration of the cell and the oncocytic phenotype. Oncocytic change may be an under-recognised histopathological change in rectal cancers receiving preoperative chemoradiation.

Expression of occludin in human rectal carcinoid tumours as a possible marker for glandular differentiation.

AIMS: To examine whether or not the tight junction-associated transmembrane protein occludin is expressed in rosette or gland-like structures in human rectal carcinoid tumours. The tight junction is crucial for the formation and maintenance of organized tubular structures in glandular epithelia. Previous studies have reported the presence of glandular structures in carcinoid tumours, though they are not believed to arise from glandular epithelium. METHODS AND RESULTS: The expression profiles of occludin in 40 carcinoid tumours were examined immunohistochemically, using an anti-occludin monoclonal antibody. In eight (20%) samples of typical carcinoid tumours, a small number of rosette-like tubular structures outlined by occludin were detected. CONCLUSIONS: Tight junction-associated molecules, including occludin, are thought to be one of the most characteristic structural markers of polarized glandular structures. The results of the present study provide supportive evidence that carcinoid tumour cells are capable of glandular differentiation.

[Electron microscopic observation of primary cultured laterally spreading tumor cell line].

OBJECTIVE: To observe the microscopic characteristics of laterally spreading tumor (LST) cell line in primary culture. METHODS: The cells isolated from a rectum LST specimen obtained by endoscopic mucosal resection was primary cultured, followed by observation with scanning and transmission electron microscope in comparison with the cells of adenocarcinoma and normal mucosa of the rectum. RESULTS: Scanning and transmission electron microscopes both revealed numerous microvilli covering the surface of the LST cells, and the cytoplasm contained large quantity of lysosomes, mitochondria and phagosomes. Obviously heterogeneous cell nuclei were present with abnormal nuclear fossa and huge nucleoli. CONCLUSION: The cultured LST cells are highly malignant.