[An exceptional hepatic tumor]. / Une tumeur hépatique exceptionnelle.

BACKGROUND: Hepatic localization of non Hodgkin's lymphoma is generally secondary. Primary localizations are rare. AIM: To report a rare case of primary hepatic lymphoma particular by its association with dermatopolymyositis. OBSERVATION: A 55-year-old woman with a past medical history of dermatopolymyositis diagnosed one year before presented with abdominal pain and fever. Laboratory tests showed pancytopenia. Radiologic examination revealed multiple hepatic masses. Surgical biopsy revealed a large B cell hepatic lymphoma. No other localizations were found so the diagnosis of primary hepatic lymphoma was retained. The patient died after a few days due to a severe sepsis. CONCLUSION: Primary hepatic lymphoma is a rare tumor with a bad prognosis. Its diagnosis is based on histologic examination. Treatment of these tumors remains non consensual.

Cytokeratin 18 expression pattern correlates with renal cell carcinoma progression: relationship with Snail.

Renal cell carcinoma (RCC) is the most common type of kidney cancer and recent developments in the molecular biology of RCC have identified multiple pathways associated with the development of this cancer. This study aimed at analyzing the expression pattern of cytokeratin 18 (CK18) in RCC patients and its prognostic relevance. We quantified CK18 mRNA expression and protein using real-time reverse transcription quantitative polymerase chain reaction (RT-QPCR) and immunohistochemistry, respectively, in paired tumor and non-tumor samples from 42 patients. Our data indicate that CK18 mRNA and proteins levels increased with advanced stage and grade of the disease. Using primary (RCC5) and metastatic renal cell carcinoma (RCC5 met) cell lines, we demonstrated that CK18 expression was 5-fold higher in the metastatic as compared to the primary RCC cell line and correlated with a migratory phenotype characterized by a distinct elongated morphology as revealed by Phalloidin staining. In addition, RCC5 met cells displayed an increased capacity to attach to fibronectin and collagen which was lost following CK18 knock-down. Our data also indicate that the expression of CK18 was associated with increased Snail expression which correlated positively with advanced disease in RCC patients. The present findings suggest that CK18 may play an important role in the progression of RCC and it may be used as a new predictor for RCC.

Combined analysis of smoking, TP53, and FGFR3 mutations in Tunisian patients with invasive and superficial high-grade bladder tumors.

In our cohort, FGFR3 mutations were detected in 31.1% of bladder tumors and are associated with lower stage and grade. Concerning TP53, 62 mutations were found in tumors from 44 cases (48.88%) and are associated with advanced forms. The combined analysis of FGFR3 and TP53 mutations in our cohort showed an independent distribution. In addition, we have reported that FGFR3 mutations spectrum depends on the intensity of tobacco use (pack years: PY). Finally, we have found that the FGFR3wt/TP53mut genotype, which was associated with advanced bladder tumors; was overrepresented in light smokers (PY < 40) compared to nonsmoker patients (p =.01).

Identification and characterization of a novel MLH1 genomic rearrangement as the cause of HNPCC in a Tunisian family: evidence for a homologous Alu-mediated recombination.

High rates of early colorectal cancers are observed in Tunisia suggesting high genetic susceptibility. Nevertheless, up to now no molecular studies have been performed. Hereditary nonpolyposis colorectal cancer (HNPCC) is the most frequent cause of inherited colorectal cancer. It is caused by constitutional mutations in the DNA mismatch repair (MMR) genes. Here, we investigated a Tunisian family highly suspected of hereditary nonpolyposis colorectal cancer (HNPCC). Six patients were diagnosed with a colorectal or an endometrial cancer at an early age, including one young female who developed a colorectal cancer at 22 years and we tested for germline mutations in MMR genes. MMR genes were tested for rearrangements by MLPA (MLH1, MSH2) and the presence of point mutations by sequencing (MLH1, MSH2, MSH6). Moreover, tumors were analyzed for microsatellite instability and expression of MMR proteins, as well as for somatic rearrangements in MLH1 and MSH2 by MLPA. MMR gene analysis by MLPA revealed the presence of a large deletion in MLH1 removing exon 6. Sequence analysis of the breakpoint region showed that this rearrangement resulted from a homologous unequal recombination mediated by a repetitive Alu sequence. Moreover, tumors harbored biallelic deletion of MLH1 exon 6 and loss of heterozygosity at MLH1 intragenic markers, suggesting duplication of the rearranged allele in the tumor. This germline MLH1 rearrangement was associated to a severe phenotype in this family. This is the first report of a molecular analysis in a Tunisian family with HNPCC.

Prevalence of mutations in APC, CTNNB1, and BRAF in Tunisian patients with sporadic colorectal cancer.

Sporadic colorectal tumorigenesis is caused by alterations in the Wnt (APC, CTNNB1) and Ras pathways. Our objective was to analyze the occurrence of these genetic alterations in relation to tumor and patient characteristics. The prevalence of somatic alteration in the hot-spot regions of the APC, BRAF, and CTNNB1 genes was investigated in 48 unselected and unrelated Tunisian patients with sporadic colorectal cancer, and the association between the molecular features at these genes in relation to tumor and patient characteristics (age at diagnosis, sex, tumor localization, stage, and differentiation) was analyzed. Loss of heterozygosity was observed at the APC locus in 52% of the analyzed tumors. 6 novel mutations were detected by polymerase chain reaction sequencing in the mutation cluster region of the APC gene. No mutations were observed in the CTNNB1 gene in any tumor, but 8% of tumors harbored mutation in the BRAF gene. Clinicopathological analyses showed an association between APC point mutations and the earliest occurrence of sporadic colorectal cancer. The findings confirm the heterogeneity of APC gene alteration and also reveal a particular profile of this pathology among Tunisian patients that confirms the epidemiological data for this country.

Multiple cutaneous bronchogenic cysts located on the neck and the scalp. A case report.

Bronchogenic cyst is a benign congenital developmental abnormality of the embryonic foregut. The skin is a rare site for bronchogenic cysts, and in this location it is often a solitary lesion. It is poorly recognized by clinicians and in almost all cases the diagnosis is established by histopathologic examination. This report documents a new case of multiple cutaneous bronchogenic cysts bilaterally located on the neck and on the scalp, which are unusual locations of this lesion.

[Collecting duct carcinoma associated with renal stones]. / Le carcinome des tubes collecteurs de Bellini associé a des calculs rénaux.

Collecting duct carcinoma is an extremely rare disease, representing less than 1% of all renal tumours. The authors report the case of a 72-year-old patient presenting with right low back pain associated with episodes of total macroscopic haematuria. Imaging showed a heterogeneous mass in the upper pole of the right kidney associated with pyelocaliceal stones. Multiple secondary lesions were observed in the liver. Macroscopically, the mid-renal tumour was 7.5 cm in diameter surrounding the stone-containing pyelocaliceal cavities. This tumour had spread to the cortex and invaded the perirenal fat. Histologically, the tumour was composed of ducts lined by cells with a hobnail appearance in an abundant desmoplastic and neutrophil-rich inflammatory stroma. Immunohistochemistry showed very intense labelling of tumour cells with cytokeratins: KL1, 7, 19, and 34_E12 and slightly less intense labelling with UER, Vimentin, EMA, and BNH9, while cytokeratin 20 was negative. The diagnosis of Fuhrman grade 3 collecting duct carcinoma associated with renal stones and liver metastases was adopted. The patient died postoperatively. The main differential diagnosis was urothelial carcinoma with a glandular component. In the present case, the diagnosis was made more difficult by the concomitant presence of renal stones. The diagnosis was established by histology and immunohistochemistry.

A new case of signet ring cell carcinoma of the prostate.

Primary signet ring cell carcinoma of the prostate is a very rare variant of prostate cancer. Herein, we report a new case of primary signet ring cell carcinoma of the prostate in an 85-year-old man with voiding disorder and hematuria. Based on this case, we present the anatomopathologic, clinical, and therapeutic aspects of this rare entity.

[Pelvic ganglioneuroma. Report of a case]. / Le ganglioneurome pelvien. A propos d'une observation.

Ganglioneuroma is a rare benign tumor. It is the most mature of neurogenic tumors. We report a case of a pelvic ganglioneuroma diagnosed in 24-year-old pregnant woman who presented with an urinary infection. Echographic examination suggested an ovarian mass. At surgical operation, the tumor was close to the sacrum. A total resection of the tumor was performed. Pathological examination proved it as a ganglioneuroma. Sixteen months later, the patient is free from disease.

[Prostatic stromal sarcoma]. / Sarcome stromal de la prostate.

Prostatic sarcoma is a very rare tumour arising from the specialized stroma of the prostatic parenchyma. The clinical and histological features and biological behaviour of this entity are poorly elucidated at the present time. The authors report a case of prostatic stromal sarcoma in a 47-year-old man presenting with complete bladder retention. The initial diagnosis was that of benign prostatic hyperplasia and the patient was treated by suprapubic prostatectomy with no other complementary treatment. Histological examination demonstrated primary neuroectodermal tumour (PNET). The patient was subsequently lost to follow-up and was only reviewed 22 months later in a context of haematuria. Digital rectal examination revealed a large, soft prostate with an estimated weight of 83 grams on ultrasound. Transurethral resection was performed and histological examination of the resection material and review of the slides of the primary tumour showed identical microscopic and immunohistochemical features, corresponding to stromal sarcoma. The patient was treated by local and regional radiotherapy (60 Grays). With a follow-up of 36 months, he presents urinary symptoms with no signs of local extension or metastasis.