Anthony N. Snow

Human papillomavirus detection in head and neck squamous cell carcinomas.

Squamous cell carcinomas of the head and neck (HNSCC) are a frequent diagnosis in anatomic pathology practice. Tobacco use and heavy alcohol consumption are known risk factors for HNSCC but in other cases human papillomavirus (HPV) is linked to carcinogenesis. HPV proteins E6 and E7 promote oncogenesis by blocking the action of p53 and pRB, respectively. An absence of p53 mutations in addition to expression of p16 are part of the distinct molecular profile identified in the subset of HNSCCs because of HPV. Various methods are available for HPV detection but polymerase chain reaction and in situ hybridization techniques are commonly used. Both methods are amenable for testing formalin-fixed paraffin-embedded tissue that is a sample type readily available to the pathologist. HPV is detectable in approximately a quarter of all HNSCCs, and is particularly prevalent in the oropharynx in which the positivity rates approach 40%. A vast majority of HPV-related HNSCCs are owing to HPV type 16 with types 18, 31, and 33 accounting for almost all of the remaining cases. HPV-related HNSCCs are associated with better prognosis for both recurrence and survival. This group of tumors has also been shown to respond well to radiation treatment. As the clinical relevance of HPV in HNSCCs continues to emerge, anatomic pathologists are likely to receive increasing requests for testing. Herein, the authors review the biological and clinical aspects of HPV-associated HNSCC and review techniques for HPV detection.

MRI of Pregnancy-Related Issues: Abnormal Placentation

OBJECTIVE In this article, we review the clinical significance of abnormal placentation and the role of MRI in diagnosis and management of this potentially morbid condition. We present our clinical perspective on diagnosing this challenging problem with MRI and review the imaging findings that can lead to a correct diagnosis. CONCLUSION As abnormal placentation becomes more prevalent, in large part due to the markedly rising rates of cesarean delivery, there is a need for accurate antenatal diagnosis of this condition to prevent maternal morbidity and mortality. Maternal and fetal outcomes can be optimized through multidisciplinary planning to achieve accurate diagnosis and anticipation of the extent of abnormal placentation in the antenatal period. Imaging findings of abnormal placentation have been described for both ultrasound and MRI, although limitations exist for each technique. Although ultrasound remains the primary screening modality for the detection of abnormal placentation, MRI is a complementary technique that should be considered when ultrasound is inconclusive or incomplete. Familiarity with MRI techniques to assess the placenta, MRI appearance of normal placenta, and imaging findings that suggest abnormal placentation can help radiologists contribute to a successful maternal outcome.

Helicobacter pylori: to stain or not to stain?

We performed a retrospective study to investigate the usefulness of immunohistochemical stains for the diagnosis of Helicobacter pylori (HP). We reviewed 200 consecutive gastric biopsy specimens, as well as immunohistochemical stains for HP. Of the biopsy specimens, 32 were positive for HP by immunohistochemical staining; of those, HP was seen on H&E stains in 29 cases (91%). The number of high-power fields required to detect HP on H&E-stained slides ranged from 1 to 25 (mean, 5.75). Combined significant (2+ or 3+) acute and chronic inflammation had a specificity of 98% and a negative predictive value of 97%. Our results show that, in our institution, HP can be seen relatively easily with H&E staining in the majority of cases; however, a small number of cases with significant inflammation can be missed if stains are not used.

MDM2 copy numbers in well-differentiated and dedifferentiated liposarcoma: characterizing progression to high-grade tumors.

OBJECTIVES MDM2 gene amplification is associated with well-differentiated (WDL) and dedifferentiated liposarcomas (DDL). Using fluorescent in situ hybridization (FISH), we sought to characterize various patterns of MDM2 amplification among the morphologic spectrum of liposarcoma. METHODS Forty-six cases of liposarcoma in various sites were examined and included 22 WDLs, 14 DLLs, and 10 negative control subjects. RESULTS The MDM2 amplification ratio (MDM2/CEP12) was lower in WDL (10.2) compared with DDL (18.3) cases (P = .0000002). An amplification ratio of 16 showed optimal sensitivity (0.86) and specificity (0.96) as a cutoff point for progression to DDL. Borderline areas, defined as tumors with increased cellularity and atypia but with preserved lipomatous differentiation, showed a significantly higher MDM2 ratio (17.5; P = .0007) compared with WDL. Central (retroperitoneal and intra-abdominal) tumors also showed a significantly higher MDM2 ratio than peripheral ones (P = .02). CONCLUSIONS Differences in MDM2 amplification profiles among liposarcomas could help further define and predict progression to high-grade neoplasia.

Esophageal eosinophilia in pediatric patients with celiac disease: is it a causal or an incidental association?

Objectives: Celiac disease (CD) and eosinophilic esophagitis (EoE) are 2 distinct disease entities affecting the gastrointestinal tract of pediatric patients. Recently it has been suggested that EoE is more prevalent in patients with celiac disease than in the general population. We studied the association between these 2 disease entities in our pediatric patients. Methods: We reviewed our hospital files for suspected or confirmed cases of CD. Only cases with both duodenal and esophageal biopsies in pediatric patients were included. A total of 120 patients who met these criteria were included as the disease group. We also selected 100 patients with no clinical suspicion of CD and included them as a control group. Slides were reviewed using established criteria for diagnosis of both conditions. Duodenal biopsies were categorized as positive, negative, and suspicious for CD, whereas esophageal biopsies were classified as either positive or negative for esophageal eosinophilia (EE). Serologic and clinical data were additionally collected. Results: Sixty-two (62) cases were considered positive for CD in the disease group; among those 4 (6.5%) showed EE. In the control group, 91 cases were negative for CD, histologically, and 7 of those had EE (7.7%). Although 6 patients in the control group were histologically suspicious for CD, none of them had evidence of EE. Conclusions: Our findings show that, in our patient population, patients with CD are not more likely to have EE than patients undergoing upper endoscopy for other reasons. Therefore, we suggest that the association between CD and EE is likely incidental and not causal.

Incidental prostate cancer diagnosed at radical cystoprostatectomy for bladder cancer: disease-specific outcomes and survival

Background The current standard of care for men with muscle-invasive bladder cancer is radical cystoprostatectomy (RCP). One-third of RCP specimens demonstrate incidental prostate cancer, primarily reported in small series with limited follow-up. The aim of this study is to report mature outcomes, including patterns of failure and disease-specific recurrence rates, and survival, for a large cohort of men with incidental prostate cancer at RCP performed at a tertiary referral center. Methods This retrospective study describes cancer control and survival rates for men who underwent RCP for bladder cancer and were found incidentally to have prostate cancer. Analysis of patient-, tumor-, and treatment-specific factors were analyzed for association with disease control and survival endpoints. Results Between 2002 and 2010, 94 patients with incidental discovery of prostate cancer postRCP were identified for inclusion in this study. Forty-five patients (45%) underwent RCP for recurrent (rather than initial presentation of) bladder carcinoma. At a median follow-up of 40.3 months (71.2 months for survivors; range, 8.9–155.5 months), 42 patients were alive without recurrence and 52 patients had died (25 associated with disease). The estimated 5-year bladder cancer disease-free, urinary tract malignancy disease-free, and prostate specific antigen (PSA) relapse-free survivals were 76% [95% confidence interval (CI), 65–84%], 64% (52–74%), and 97% (79–100%), respectively. The estimated 5-year urinary tract malignancy-specific and overall survivals were 61% (49–71%) and 52% (41–62%), respectively. Univariate analysis demonstrated associations between pathologic T/N-stage and nodal ratio with bladder cancer disease-free, urinary tract malignancy disease-specific, and overall survivals, with patient age at diagnosis as an additional adverse factor associated with overall survival. Multivariate analysis confirmed pN-stage and age as independently associated with worse survival. Conclusion For men undergoing RCP for bladder cancer, the present study suggests that incidentally discovered prostate cancers, irrespective of pathologic stage, Gleason score, or clinical significance, do not impact 5-year disease control or survival outcomes.

Expression of cadherin 17 in well-differentiated neuroendocrine tumours.

Cadherin 17 (CDH17) is expressed primarily in normal intestinal epithelium and digestive tract tumours, and has limited expression in other neoplasms. The aims of this study were to examine CDH17 expression in well‐differentiated neuroendocrine tumours (WDNETs) from various primary sites, representing the foregut, midgut, and hindgut, and tumours metastasizing to the liver, and to correlate the differences between the expression of CDH17, CDX2, and thyroid transcription factor 1 (TTF1).

Oncocytoma-Like Renal Tumor With Transformation Toward High-Grade Oncocytic Carcinoma A Unique Case With Morphologic, Immunohistochemical, and Genomic Characterization

AbstractRenal oncocytoma is a benign tumor with characteristic histologic findings. We describe an oncocytoma-like renal tumor with progression to high-grade oncocytic carcinoma and metastasis.A 74-year-old man with no family history of cancer presented with hematuria. Computed tomography showed an 11 cm heterogeneous multilobulated mass in the right kidney lower pole, enlarged aortocaval lymph nodes, and multiple lung nodules. In the nephrectomy specimen, approximately one third of the renal tumor histologically showed regions classic for benign oncocytoma transitioning to regions of high-grade carcinoma without sharp demarcation.With extensive genomic investigation using single nucleotide polymorphism-based array virtual karyotyping, multiregion sequencing, and expression array analysis, we were able to show a common lineage between the benign oncocytoma and high-grade oncocytic carcinoma regions in the tumor. We were also able to show karyotypic differences underlying this progression. The benign oncocytoma showed no chromosomal aberrations, whereas the high-grade oncocytic carcinoma showed loss of the 17p region housing FLCN (folliculin [Birt–Hogg–Dubé protein]), loss of 8p, and gain of 8q. Gene expression patterns supported dysregulation and activation of phosphoinositide 3-kinase (PI3K)/v-akt murine thymoma viral oncogene homolog (Akt), mitogen-activated protein kinase (MAPK)/extracellular-signal-regulated kinase (ERK), and mechanistic target of rapamycin (serine/threonine kinase) (mTOR) pathways in the high-grade oncocytic carcinoma regions. This was partly attributable to FLCN underexpression but further accentuated by overexpression of numerous genes on 8q. In the high-grade oncocytic carcinoma region, vascular endothelial growth factor A along with metalloproteinases matrix metallopeptidase 9 and matrix metallopeptidase 12 were overexpressed, facilitating angiogenesis and invasiveness.Genetic molecular testing provided evidence for the development of an aggressive oncocytic carcinoma from an oncocytoma, leading to aggressive targeted treatment but eventual death 39 months after the diagnosis.

A simple and cost-effective method of DNA extraction from small formalin-fixed paraffin-embedded tissue for molecular oncologic testing

BackgroundExtraction of DNA from formalin-fixed, paraffin-embedded (FFPE) tissue is a critical step in molecular oncologic testing. As molecular oncology testing becomes more important for prognostic and therapeutic decision making and tissue specimens become smaller due to earlier detection of suspicious lesions and the use of fine needle aspiration methods for tissue collection, it becomes more challenging for the typical molecular pathology laboratory to obtain reliable test results. We developed a DNA extraction method to obtain sufficient quantity and high quality genomic DNA from limited FFPE tissue for molecular oncology testing using a combination of H&E stained slides, a matrix capture method and the Qiagen DNA column.MethodsThree DNA extraction methods were compared: our standard procedure of manually scraping tissue from unstained slides followed by DNA extraction using the QIAamp FFPE column (Qiagen, Valencia, CA), a glue capture method (Pinpoint Solution, Zymo Research Corp, Inc) on H&E stained slides followed by DNA extraction using either the QIAamp column or the column included with the Pinpoint kit (Zymo Research). The DNA extraction protocol was optimized. Statistical analysis was performed using the paired two-sample student’s t-test.ResultsThe combination of the matrix capture method with the QIAamp column gave an equivalent amount of DNA as our standard extraction method using the unstained slides and a 4.6-fold higher DNA yield than using the Zymo column included in the Pinpoint Slide Solution kit. Several molecular tests were performed and DNA purified using the new method gave the same results as for the previous methods.ConclusionsUsing H&E stained slides allows visual confirmation of tumor cells during microdissection. The Pinpoint solution made removal of specific tissue from the slides easier and reduced the risk of contamination and tissue loss. This DNA extraction method is simple, cost-effective, and blends with our current workflow requiring no additional equipment.

Head and Neck Tumors

Molecular testing for head and neck squamous mucosal lesions and salivary gland tumors is becoming part of routine practice. Viral oncogenesis is implicated in both head and neck squamous cell carcinoma and nasopharyngeal carcinoma. Human papillomavirus (HPV) is detected in a majority of oropharyngeal squamous cell carcinomas and is associated with improved response to treatment. Detection of Epstein Barr Virus (EBV) in nasopharyngeal carcinoma is diagnostically useful. For salivary gland tumors, characteristic translocations with resultant fusion oncogenes have been identified. These genetic rearrangements can be detected by fluorescence in situ hybridization (FISH) testing and have diagnostic utility. These oncogenes also provide hope as therapeutic targets. ERBB2 (HER2) is one therapeutic target that has a role in salivary duct carcinoma. A subset of this tumor overexpresses ERBB2, and stabilization of disease has been reported with trastuzumab therapy.