KRAS mutation detection in paired frozen and Formalin-Fixed Paraffin-Embedded (FFPE) colorectal cancer tissues

KRAS mutation has been unambiguously identified as a marker of resistance to cetuximab-based treatment in metastatic colorectal cancer (mCRC) patients. However, most studies of KRAS mutation analysis have been performed using homogenously archived CRC specimens, and studies that compare freshly frozen specimens and formalin-fixed paraffin-embedded (FFPE) specimens of CRC are lacking. The aim of the present study was to evaluate the impact of tissue preservation on the determination of KRAS mutational status. A series of 131 mCRC fresh-frozen tissues were first analyzed using both high-resolution melting (HRM) and direct sequencing. KRAS mutations were found in 47/131 (35.8%) using both approaches. Out of the 47 samples that were positive for KRAS mutations, 33 had available matched FFPE specimens. Using HRM, 2/33 (6%) demonstrated suboptimal template amplification, and 2/33 (6%) expressed an erroneous wild-type KRAS profile. Using direct sequencing, 6/33 (18.1%) displayed a wild-type KRAS status, and 3/33 (9.1%) showed discordant mutations. Finally, the detection of KRAS mutations was lower among the FFPE samples compared with the freshly frozen samples, demonstrating that tissue processing clearly impacts the accuracy of KRAS genotyping.

Histologic and immunohistologic characterization of skin localization of myeloid disorders: a study of 173 cases

A retrospective analysis of 173 skin biopsy specimens of myeloid leukemia cutis (MLC) was performed to determine histologic and immunophenotypic criteria that could distinguish the varied myeloid disorders from one another. For the study, 11 relevant histologic items were scored and 12 antigens were studied (CD68 [KP1], CD163, CD14, CD4, myeloperoxidase [MPO], CD33, CD117, CD34, CD56, MIB-1, CD303, and CD123). Underlying myeloid disorders were essentially acute myeloid leukemias (65.3%), chronic myelomonocytic leukemias (11.0%), and refractory anemia (10.4%). Skin lesions were de novo in 7.5%, concurrent in 26.6%, and subsequent in 60.7%. Several morphologic characteristics (density, size of tumor cells, inflammatory background) were statistically useful in distinguishing between varied myeloid disorders. De novo MLCs displayed a specific morphologic profile. Association of CD68, CD33, and MPO could diagnose 100% of the cases of MLC. However, the immunohistochemical panel could not distinguish between the varied underlying myeloid disorders, with the exception that CD123 was particularly powerful in recognizing chronic myelomonocytic leukemia and also permitted reclassification of 4 cases as blastic plasmacytoid dendritic cell neoplasm.

Prognostic value of a three-grade classification in primary epithelial parotid carcinoma: result of a histological review from a 20-year experience of total parotidectomy with neck dissection in a single institution

BACKGROUND

The tumour grading of primary parotid cancers (PPCs) remains controversial.

METHODS

A 20-year standardised single centre treatment has been assessed retrospectively. The histological review of 155 consecutively treated parotid malignancies identified 96 suitable cases for univariate and multivariate survival analyses.

RESULTS

Treatment involved total parotidectomy, neck dissection and post-operative radiotherapy in, respectively, 91.7%, 83.3% and 70.4% of cases. The 5-year overall survival, disease-specific and recurrence-free survival rates were 79.4%, 83.5% and 70.8%, respectively. Univariate analysis confirmed the classical prognostic factors, i.e. age>60 years, male gender, facial palsy, hardness of the tumour, clinical stage, tumour grade, facial nerve invasion and lymph node metastases. Multivariate analysis identified a three-grade classification just after the clinical stage as the most important prognostic factor.

CONCLUSION

This study identifies the prognostic significance of intermediate grade tumours.

Neck restaging with sentinel node biopsy in T1-T2N0 oral and oropharyngeal cancer: Why and how?

Objective: To evaluate the lack of accuracy in neck staging with the classical technique (i.e., neck dissection and routine histopathology) with the sentinel node (SN) biopsy in oral and oropharyngeal T1-T2N0 cancer.

Study Design: Cross-sectional study with planned data collection.

Setting: Tertiary center care.

Subjects and Methods: In 50 consecutive patients, the pathological stage of sentinel node (pSN) was established after analyzing SN biopsies (n = 148) using serial sectioning and immunohistochemistry. Systematic selective neck dissection was performed. The pN stage was established with routine histopathologic analysis of both the non-SN (n = 1075) and the 148 SN biopsies.

Results: The sensitivity and negative predictive value of pSN staging were 100 percent. Conversely, if one considers pSN staging procedure as the reference test for micro- and macro-metastasis diagnosis, the sensitivity of the classical pN staging procedure was 50 percent (9/1; 95% CI 26.9-73.1) and its negative predictive value was 78 percent (95% CI 61.9-88.8). Fifteen patients (30%) were upstaged, including nine cases from pN0 to pSN ≥ 1 and six cases from pN1 to pSN2. Two of the pN0-pSN1 upstaged patients died with relapsed neck disease.

Conclusion: The SN biopsy technique appeared to be the best staging method in cN0 patients and provided evidence that routinely undiagnosed lymph node invasion may have clinical significance.

[Adenocarcinomas of nasal cavities and paranasal sinuses: Diagnostic pitfalls in sinonasal glandular lesions]

Among primitive adenocarcinoma of nasal cavity and paranasal sinus, the 2005 WHO classification distinguishes two main categories: intestinal type adenocarcinoma (ITAC) and low-grade non-intestinal adenocarcinoma, entities with different clinical and epidemiological characteristics. Low-grade adenocarcinoma shows a respiratory type phenotype (CK20-/CK7+/CDX2-/villin-) and ITACs, an intestinal type profile (CK20+/CK7-/CDX2+/villin+). Because of histological, ultrastructural and phenotypical similarities between ITAC and colorectal adenocarcinomas, several studies have discussed a possible common pathway in carcinogenesis. But the review of literature shows conflicting results, suggesting different pathways of pathogenesis. Differential diagnoses of sinonasal intestinal-type adenocarcinoma are mainly respiratory epithelial adenomatoid hamartomas, inverted schneiderian papillomas, salivary glands-type carcinoma and more rarely metastasis of adenocarcinoma.

Activation of MAP kinase (ERK1/2) in human neonatal colonic enteric nervous system

The aim of this study was to examine mitogen-activated protein kinase (ERK1/2) activation in the human neonatal colonic enteric nervous system. For this, we investigated by immunocytochemistry the cellular localization of phosphorylated ERK1/2 (P-ERK) in a series of normal human colon samples removed from newborns and in patients with intestinal obstruction such as Hirschsprung's disease (HSCR), stenosis and atresia. We checked the presence of P-ERK in the three distinct histological layers of normal colon. Phosphorylated ERK was detected in the colonic mucosa, in the enteric nervous system and in endothelial cells. In the mucosa from normal colon, P-ERK was detected at the upper part of the crypt, while P-ERK activation in epithelial cells is altered in HSCR, stenosis and atresia. In the normal colon, strong P-ERK staining was detected in myenteric and submucosal enteric plexuses. Using confocal microscopy analyses, we observed that P-ERK staining was localized in enteric glial cells and not in enteric neurons. Strong P-ERK staining was also observed in plexuses from stenosis and atresia whereas in HSCR, hypertrophic nerve fibres were not stained.

Viral load and genomic integration of HPV 16 in cervical samples from HIV-1-infected and uninfected women in Burkina Faso

The relationships between human papillomavirus type 16 (HPV 16) viral load, HPV 16 integration status, human immunodeficiency virus type 1 (HIV-1) status, and cervical cytology were studied among women enrolled in a cohort of female sex workers in Burkina Faso. The study focused on 24 HPV 16-infected women. The HPV 16 viral load in cervical samples was determined by real-time PCR. Integration ratio was estimated as the ratio between E2 and E6 genes DNA copy numbers. Integrated HPV16 viral load was defined as the product of HPV 16 viral load by the integration ratio. High HPV 16 viral load and high integration ratio were more frequent among women with squamous intraepithelial lesions compared with women with normal cytology (33% vs. 11%, and 33% vs. 0%, respectively), and among women with high-grade squamous intraepithelial lesions compared with women without high-grade squamous intraepithelial lesions (50% vs. 17%, and 50% vs. 11%, respectively). High HPV 16 DNA load, but not high integration ratio, was also more frequent among HIV-1-positive women (39% vs. 9%; and 23% vs. 18%, respectively). The absence of statistical significance of these differences might be explained by the small study sample size. High-integrated HPV 16 DNA load was significantly associated with the presence of high-grade squamous intraepithelial lesions (50% vs. 5%, P = 0.03) in univariate and multivariate analysis (adjusted odds-ratio: 19.05; 95% confidence interval (CI), 1.11-328.3, P = 0.03), but not with HIV-1 or other high-risk HPV types (HR-HPV). Integrated HPV 16 DNA load may be considered as a useful marker of high-grade cervical lesions in HPV 16-infected women.

Lymphome T cutané épidermotrope cytotoxique CD8+ « agressif » : difficultés de prise en charge chez un malade atteint d’une dystrophie myotonique de Steinert

INTRODUCTION

Primary cutaneous "aggressive" CD8-positive epidermotropic cytotoxic T-cell lymphoma is a rare subset of cutaneous cytotoxic T/NK lymphomas that clearly differs from mycosis fungoides, whether CD4+ or CD8+, by the presence of rapidly evolving tumoral cutaneous lesions, foci of keratinocytes necrosis, a cytotoxic T phenotype and a poor prognosis.

CASE REPORT

A 33-year-old man with Steinert's myotonic dystrophy was referred for evaluation of rapidly worsening cutaneous tumors along with marked deterioration of general status. Clinical, histological and immunohistological data led to the diagnosis of primary cutaneous CD8+ epidermotropic cytotoxic T-cell lymphoma. CHOP chemotherapy was effective despite cardiac toxicity in the setting of Steinert's dystrophy, but the patient relapsed and died of pulmonary sepsis after chemotherapy was resumed.

DISCUSSION

The treatment of primary cutaneous epidermotropic CD8+ cytotoxic T-cell lymphoma is not codified. CHOP chemotherapy is usually the first-line therapy but relapses are frequent with median survival of no more than 34 months. In our patient, an additional difficulty was the cardiac toxicity of cytostatic drugs linked to the myopathy which prevented the use of high dosages, requiring a change of therapeutic regimen.

The Diagnostic Accuracy of Reverse Transcription-PCR Quantification of Cytokeratin mRNA in the Detection of Sentinel Lymph Node Invasion in Oral and Oropharyngeal Squamous Cell Carcinoma: A Comparison with Immunohistochemistry

PURPOSE

The main goal of sentinel lymph node (SLN) detection in head and neck squamous cell carcinomas is to limit neck dissections to pN+ cases only. However, intraoperative + diagnosis cannot be routinely done using the current gold standard, serial step sectioning with immunohistochemistry. Real-time quantitative reverse transcription-PCR (RT-PCR) is potentially compatible with intraoperative use, proving highly sensitive in detecting molecular markers. This study postoperatively assessed the accuracy of quantitative RT-PCR in staging patients from their SLN.

EXPERIMENTAL DESIGN

A combined analysis on the same SLN by serial step sectioning with immunohistochemistry and quantitative RT-PCR targeting cytokeratins 5, 14, and 17 was done in 18 consecutive patients with oral or oropharyngeal squamous cell carcinoma and 10 control subjects.

RESULTS

From 71 lymph nodes examined, mRNA levels (KRT) were linked to metastasis size for the three cytokeratins studied (Pearson correlation coefficient, r = 0.89, 0.73, and 0.77 for KRT 5, 14, and 17 respectively; P < 0.05). Histopathology-positive SLNs (macro- and micrometastases) showed higher mRNA values than negative SLNs for KRT 17 (P < 10(-4)) and KRT 14 (P < 10(-2)). KRT 5 showed nonsignificant results. KRT 17 seemed to be the most accurate marker for the diagnosis of micrometastases of a size >450 mum. Smaller micrometastases and isolated tumor cells did not provide results above the background level. Receiver operating characteristic curve analysis for KRT 17 identified a cutoff value where patient staging reached 100% specificity and sensitivity for macro- and micrometastases.

CONCLUSION

Quantitative RT-PCR for SLN staging in cN(0) patients with oral and oropharyngeal squamous cell carcinoma seems to be a promising approach.

[How can the diagnostic value of head and neck biopsies be increased in Wegener's granulomatosis: a clinicopathologic study of 49 biopsies in 21 patients]

Head and neck biopsies usually have a low diagnostic value in Wegener's granulomatosis (WG). On the basis of 49 biopsies obtained from 21 WG patients at diagnosis from various sites, i.e. nose (29), paranasal sinus (7), oral cavity (4), larynx (4), conjunctiva (3) and external ear (2), we described the suggestive histological features and studied the diagnostic potential of the biopsy size, anaesthesia method (general (GA) or local (LA)), anatomic region of the biopsy, number of sections, and presenting macroscopic manifestations. Associated granulomatous inflammation (scattered giant cells, 28.5% of biopsies; poorly-formed granulomas, 28.5%), necrosis (neutrophilic microabscesses, 16.3%; geographic necrosis, 18.3%), angiitis (leukocytoclastic, 10%; necrotizing, 12%; and granulomatous, 6%) which confirmed the diagnosis were only present in 18.3% of the biopsies (28.5% of the patients). We think it is possible to propose a "WG-compatible" diagnosis when at least one of these histological features is present (24.5% of biopsies, 26% of patients in our study). We found that it was always better to perform biopsies targeted on macroscopic lesions. When there was no lesion, samples from paranasal sinuses obtained under GA had the highest diagnostic value in the head and neck region, whereas 90% of nasal systematic biopsies performed under LA were nonspecific. Moreover, we demonstrated that performing two further sections increased the sensitivity of histological examination by 7%.

Alcohol relapse after liver transplantation for alcoholic liver disease: does it matter?

BACKGROUND/AIMS

The aim of this study was to distinguish the types of alcohol consumption after liver transplantation (LT) for alcoholic cirrhosis and to assess the consequences of heavy drinking.

METHODS

Patients transplanted for alcoholic cirrhosis were studied. Alcoholic relapse diagnosis was based upon patient's and family members' reports, liver enzyme tests, graft biopsy, and use of urine alcohol test.

RESULTS

One hundred twenty-eight patients were studied, with a mean follow-up of 53.8 months. After LT, 69% of patients were abstinent, 10% were occasional drinkers, and 21% were heavy drinkers. Actuarial survival rates were not different, but three of the seven deaths observed among heavy drinkers were directly related to alcohol relapse. Although there was no difference between the three groups concerning the rejection rates, all rejection episodes observed in the group of heavy drinkers were related to poor compliance with immunosuppressive drugs. One heavy drinker developed alcoholic cirrhosis.

CONCLUSIONS

The present study indicates that patients can resume heavy alcohol consumption after LT for alcoholic liver disease (ALD) and their grafts can be injured because of poor compliance with immunosuppressive drugs and alcohol-related liver injury. Although patient survival was not influenced by alcohol relapse, heavy alcohol consumption can be responsible for patients' death.