Surgical resection of retrorectal tumours in adults: long-term results in 47 patients

AIM

Retrorectal tumours (RT) are uncommon, and diagnosis and management remain difficult. The aim of this study was to evaluate the results of the surgical management of RT in our institution.

METHOD

Medical notes of all patients operated on for RT were reviewed. Clinical, radiological, surgical, histological data as well as morbidity and long-term results were noted.

RESULTS

Forty-seven patients [34 women (72%), mean age 45.8 (range 17-85) years] underwent surgery for RT between 1997 and 2011. The commonest symptoms were pain (n = 31) and suppuration (n = 10). Thirty-nine (83%) patients underwent preoperative magnetic resonance imaging (MRI). Malignant lesions exhibited typical characteristics on MRI including heterogeneity (n = 5, 83%), solid appearance (n = 4, 67%), a low-T1 signal and high-T2 intensity (n = 5, 83%), enhancement after gadolinium injection (n = 5, 83%), irregular margin (n = 4, 67%) and extension above S3 (i = 5, 83%). A Kraske approach was used in 42 (89%) patients with resection of the coccyx in 25 (60%) and an abdominal or combined approach for the remaining five. Four patients developed complications (two haematoma, two abscess), but only one (haematoma) required reoperation. Histological examination showed 38 (80.9%) benign lesions. After a median follow-up of 71 (2-168) months, 5-year disease-free survival was 75% for malignant lesions and 93.1% for benign lesions (P = 0.023). Four (4/42; 9.5%) patients had moderate perineal pain after a Kraske approach, while no anal dysfunction was seen.

CONCLUSION

Magnetic resonance imaging was the most helpful investigation for retrorectal tumours. The posterior trans-sacrococcygeal approach is the procedure of choice for complete resection for most, especially for benign and cystic lesions without extension above S2.

Hereditary intraductal papillary mucinous neoplasm of the pancreas

Intraductal papillary mucinous neoplasm (IPMN) is a rare pancreatic tumor defined as intraductal mucin-producting neoplasm with tall, columnar, mucin-containing epithelium. IPMN have already been described in association with inherited genetic disorder including familial adenomatous polyposis and Peutz-Jeghers syndrome. However, there is no reported description of familial history of IPMN. We reported in this case-report IPMN in the first-degree relatives without familial history of colorectal polyposis or previous extra-pancreatic cancer. The rarety of IPMN suggests that the coexistence of this tumor in two first-degree relatives is probably due to a genetic inherited factor that remains to be elucidated.

[Autoimmune pancreatitis mimicking an intra-ductal papillary mucinous neoplasm of the pancreas: an original case]

In recent years, autoimmune pancreatitis (AIP) has been increasingly recognized. It can be associated with diabetes mellitus and other systemic autoimmune diseases, or with bile ducts lesions, which are also responsive to steroid therapy as pancreatic lesions. We report the case of a 34-year-old man with a history of a first acute pancreatitis, attributed to an intraductal papillary-mucinous neoplasm of the pancreas (IPMN) with segmental involvement of the main pancreatic duct. A spleno-pancreatectomy was performed, and pathological examination of the specimen diagnosed autoimmune pancreatitis. A treatment with corticosteroids was carried out. To our knowledge, this is the first reported case of AIP mimicking IPMN of the main pancreatic duct.

Immunohistochemical staining for mismatch repair proteins, and its relevance in the diagnosis of hereditary non-polyposis colorectal cancer

BACKGROUND

Hereditary non-polyposis colorectal cancer (HNPCC) arises mostly from germline mutations of the mismatch repair genes MSH2 and MLH1. The diagnosis of HNPCC is based on a set of clinical criteria that may be too restrictive to identify all affected patients. Immunohistochemical staining (IHC) for the mismatch repair proteins, MutS homologue 2 (MSH2) and MutL homologue 1 (MLH1), reliably identifies the microsatellite instability phenotype. This study evaluated the ability of IHC to detect germline mutations in an unselected group of patients with colorectal cancer (CRC).

METHODS

All patients with CRC operated on between July 2000 and March 2003, and demonstrating a loss of protein, were contacted. Following informed consent, searchs for germline mutation and methylation of the promoter were performed on normal and tumoral DNA.

RESULTS

Thirty patients agreed to participate, four of whom fulfilled the Amsterdam II criteria. Loss of expression of MLH1 was found in 20 patients, and loss of expression of MSH2 in ten patients. Four of the MLH1-deficient patients had a germline MLH1 point mutation (positive predictive value (PPV) 20 (95 per cent confidence interval (c.i.) 2 to 38 per cent) and 11 had promoter methylation. Seven of the MSH2-deficient patients had a germline MSH2 point mutation (PPV 70 (95 per cent c.i. 54 to 96 per cent), and none showed promoter methylation.

CONCLUSION

MLH1-deficient patients who are young or have a positive family history of cancer should be referred for genetic testing and counselling, whereas MSH2-deficient patients should be counselled in the same way as patients with HNPCC.

Clusterin is highly expressed in pancreatic endocrine tumours but not in solid pseudopapillary tumours

AIMS

Clusterin is a sulphated glycoprotein, implicated in many processes, including tumorigenesis. Several studies have reported its overexpression in many human neoplasms, including prostatic and pancreatic adenocarcinoma, but its expression has not been described previously in other pancreatic tumours. Our aim was to investigate the expression of clusterin by immunohistochemistry in 30 endocrine pancreatic tumours (ENTs) and 22 solid pseudopapillary tumours (SPPTs) to document its potential in differential diagnosis, and the possible correlation between this expression and clinicopathological parameters.

METHODS AND RESULTS

Cytoplasmic positivity was scored qualitatively (weak, moderate or strong immunoreactivity) and quantitatively on a four-tiered scale. The pattern of immunoreactivity (cytoplasmic, secretory or Golgi pattern) was also assessed. Except for scattered tumour cells in five cases, all SPPTs were negative, while all ENTs showed strong immunoreactivity in a variable proportion of tumour cells. Neither the reactivity score nor the pattern of immunoreactivity was correlated with tumour size, vascular permeation, perineural invasion or lymph node metastasis.

DISCUSSION

The expression of clusterin in all ENTs is of interest and could be an additional useful marker in the differential diagnosis with SPPTs. However, the lack of correlation between clusterin expression and clinicopathological parameters rules out a role as a predictive marker for endocrine tumour aggressiveness.

[Solitary fibrous tumor of the liver]

Solitary fibrous tumor (SFT) is commonly found on serosal surfaces, and is rarely localized in the liver. There are benign and malignant variants of hepatic SFT. We report a new case of benign SFT. Our patient, a 63-year old woman, who has been followed for 5 years for an asymptomatic liver mass, was admitted for abdominal pain. Ultrasonography (US), CT, MR Imaging and angiography showed the liver mass with typical imaging features, situated in the right hepatic lobe with blood supply from the hepatic artery. Histopathological examination demonstrated a highly vascularized tumor, composed of short spindle cells alternating with hypocellular collagenous regions, with a hemangiopericytoma-like vascular pattern. The immunohistochemical staining was positive for CD 34. Tumor resection was performed. Follow-up 8 years after the resection showed no tumor recurrence or metastasis, thus confirming the initial diagnosis of benign SFT.

Prognostic significance of microsatellite instability determined by immunohistochemical staining of MSH2 and MLH1 in sporadic T3N0M0 colon cancer

BACKGROUND

Microsatellite instability (MSI) has been identified as a factor with good prognosis and chemosensitivity in stage III C colon cancer. The purpose of this study was to evaluate the routine use of immunohistochemical analysis (immunohistochemical staining of MSH2 and MLH1) to identify T3N0M0 (stage II) colon cancer with MSI and assess the prognostic value of this analysis. The study was conducted in a large cohort of patients in a single institution who had a curatively resected T3N0M0 colon cancer and were not receiving adjuvant therapy.

METHODS

Between June 1995 and December 2001, 142 patients (77 females) with a mean age of 68 years, suffering from T3N0M0 colon cancer curatively resected and not receiving adjuvant therapy, were checked in terms of their follow up status. The results of colonoscopy, hepatic ultrasonography, chest x ray, and blood carcinoembryological antigen were noted. All tumours were immunohistochemically stained for MSH2 and MLH1. Perineural invasion, lymphovascular invasion, and the presence of vascular neoplastic emboli were assessed.

RESULTS

Twenty four patients (17%) had MSI tumours. Patients with MSI and microsatellite stable (MSS) tumours did not differ in terms of age, perineural or lymphovascular invasion, or the presence of vascular neoplastic emboli. Patients with MSI tumours were more frequently female (18/24 v 60/118; p = 0.001) and more frequently suffered from right sided cancer (19/24 v 58/118; p<0.001). Patients with MSI tumours exhibited significantly better recurrence free survival than those with MSS tumours (p = 0.02). Cox analysis identified age and MSI determined by immunohistochemistry as independent predictive factors of good prognosis (p = 0.009, odds ratio 1.04 (1.01-1.08); p = 0.04, odds ratio 7.9 (1.05-59.6)).

CONCLUSIONS

MSI determined by immunohistochemistry is an independent predictive factor of good prognosis in T3N0M0 colon cancer. The prognosis for MSI T3N0M0 colon cancer is excellent and chemotherapy should not be proposed in these patients as immunohistochemical analysis produces rapid results.

Immunohistochemical analysis of adenocarcinoma of the small intestine: a tissue microarray study

BACKGROUND

Primary adenocarcinomas of the small intestine are rare, and the genetic mechanisms involved in their carcinogenesis remain unclear.

AIM

To examine the expression of candidate proteins in small intestinal adenocarcinomas by immunohistochemistry performed on tissue microarrays (TMAs).

METHODS

Twenty seven primary sporadic small intestinal adenocarcinomas were analysed. The TMA technique was validated by comparing immunohistochemical labelling of hMLH1 and hMSH2 on TMAs and the tissue sections they derived from. The expression of Smad4, hMSH6, beta catenin, and p53 was investigated and results compared with those obtained in 14 malignant ampullary tumours.

RESULTS

TMA technology with threefold redundancy adequately represented the immunohistochemical pattern of small intestinal adenocarcinomas. Loss of hMLH1 expression, but not hMSH2 or hMSH6, was seen in two of 27 small intestinal adenocarcinomas. All ampullary tumours showed nuclear staining for hMSH2 and hMSH6. One case showed lack of immunostaining for hMLH1. Smad4 expression was absent in five small intestinal adenocarcinomas and two ampullary tumours. Overexpression of p53 was detected in the nuclei of 14 of the 27 small intestinal adenocarcinomas, and five of the 14 ampullary tumours. Nuclear or cytoplasmic expression of beta catenin was present in all specimens.

CONCLUSION

Inactivation of the SMAD4/DPC4 gene seems to be involved in small intestinal adenocarcinoma tumorigenesis. Overexpression of p53 and abnormal expression of beta catenin are two common events, unlike the loss of expression of the DNA mismatch repair proteins (hMLH1, hMSH2, and hMSH6). The carcinogenetic process appears to be similar in small intestinal adenocarcinomas and malignant ampullary tumours.

Endometrial stromal sarcoma of the rectosigmoid colon arising in extragonadal endometriosis and revealed by portal vein thrombosis

Malignant transformation is an infrequent complication of endometriosis. The ovary is the primary site in 76% of cases, and extragonadal sites are identified in 24%. Endometrioid carcinoma is the most common histologic type; sarcoma is very rare. We report a case of low-grade endometrial stromal sarcoma of the rectosigmoid colon presenting with epigastric pain due to portal vein thrombosis. This tumor arose from extragonadal endometriosis in a 61-year-old woman and was treated by surgical resection. The main differential diagnosis of this unusual colonic neoplasm includes primary mesenchymal tumors, such as gastrointestinal stromal tumors.

Fine-needle aspiration of hepatocellular carcinoma: False-negative result due to epithelioid cells

The presence of epithelioid cells in fine-needle aspirations of a liver nodule is rare, but may complicate the diagnosis of the nodule. We report on a case of a liver nodule in hepatitis C cirrhosis. Results of fine-needle aspiration mainly revealed the presence of epithelioid cells, without any recognizable tumor cells. Histological examination of the nodule after surgical resection showed a hepatocellular carcinoma with numerous epithelioid and gigantocellular granulomas, without necrosis.

Influence of fetal calf serum, fibroblast growth factors, and hepatocyte growth factor on three-dimensional cultures of human keratocytes in collagen gel matrix

BACKGROUND

We set out to evaluate the influence of fetal calf serum, acidic fibroblast growth factor (aFGF), basic fibroblast growth factor (bFGF), and hepatocyte growth factor (HGF) on three- dimensional cultures of human keratocytes in type I collagen gel matrix.

METHODS

Polymerized gels were cultured at 37 degrees C for 35 days. Gel contraction and integrated optical density were assessed 3 times weekly for 5 weeks using an image analysis system. Gels were studied at the end of the culture period by means of transmission electron microscopy (TEM) and immunochemistry.

RESULTS

Serum significantly increased gel contraction and decreased gel optical transmittance. Keratocyte density was significantly increased by serum and HGF. In TEM, collagen density was higher with serum-supplemented media than with serum-free media, and higher with HGF-supplemented media than with HGF-free media. Immunoperoxidase staining of keratocyte-populated gels showed positive staining for vimentin, connexin 43, and type I, type V, and type VI human collagen, whereas no expression of desmin, alpha smooth muscle actin, and type IV collagen was observed. Expression of type I collagen was significantly increased by aFGF and HGF, expression of type VI collagen by serum and bFGF.

CONCLUSION

Serum and HGF improve ultrastructural and immunochemical features of human keratocyte-populated collagen gels.

[Ultrastructural and immunohistochemical study of 3-dimensional cultures of human keratinocytes on a collagen gel]

PURPOSE

To investigate the ultrastructural and immunochemical features of three-dimensional cultures of human keratocytes in collagen gel matrix.

METHODS

Human keratocytes were obtained from primary cultures of stromal explains. They were cultured in bovine type I collagen gel matrix for 6 weeks. Keratocyte-populated gels were analyzed by means of immunochemistry and transmission electron microscopy.

RESULTS

Human keratocytes cultured in collagen gel matrix developed processes and formed networks of connecting cells. They showed positive staining for vimentin, collagen I, V, and VI, and connexin. Electron microscopy showed elongated cells with processes and gap junctions. Keratocytes synthesized collagen fibrils and filaments. No fibrils' organization similar to that observed in the normal human corneal stroma (i.e. parallel bundles of collagen fibrils) was observed.

CONCLUSION

Ultrastructure and immunochemical phenotype of three-dimensional cultures of human keratocytes in collagen gel matrix are similar to those observed in situ. These cultures represent a useful in vitro model to study the different corneal stroma components.