Simona Pigozzi

Cell proliferation of squamous epithelium in gastro-oesophageal reflux disease: correlations with clinical, endoscopic and morphological data

Background  The microscopic assessment of squamous epithelium lesions in gastro‐oesophageal reflux disease (GERD) is subjective. The Ki67 nuclear antigen expressed by proliferating cells provides an objective measure of regeneration in the squamous epithelium.

Immunohistochemistry on old archival paraffin blocks: is there an expiry date?

Few studies have focused on antigen preservation in formalin-fixed and paraffin-embedded (FFPE) tissue in old archival material and additional studies are required, especially considering that these samples are an irreplaceable resource for scientific and clinical research. The purpose of this study is to verify antigen preservation in FFPE tissue samples stored for several decades. From the pathology archives, FFPE blocks were selected dating back to the 1960s, 1970s, 1980s, 1990s, 2000s and 2010. A panel of 12 antibodies was applied and immunoreactivities were compared. While cytoplasmic antigens showed no reduction in immunostaining intensity over time, membrane and nuclear antigens presented reduced staining intensity in older blocks. In particular, the nuclear antigen, Ki67 and CD31 showed the most pronounced antigen decay in the oldest archival blocks. In order to test possible antigen recovery, deep sectioning and lengthening of heat pretreatment were applied. Both strategies partially recover antigenicity, but their simultaneous application shows the best results.

Section detachment in immunohistochemistry: causes, troubleshooting, and problem-solving

Section detachment in immunohistochemistry (IHC) is a common phenomenon, increasing times and costs of diagnosis and research. However, it has poorly been investigated. The aim of this study was to identify the causes of section detachment, with the purpose of defining a quality assured laboratory procedure to minimize detachment frequency. We screened 3349 IHC sections from formalin-fixed paraffin-embedded tissue, identifying 177 cases with section detachment (5.3% of the sample). Detachment regarded mainly samples of surgical breast tissue and IHC procedures in which heat pretreatment was used. Focusing on pre-analytical factors, we investigated seven main critical issues: (1) section aging; (2) section thickness; (3) slide contamination; (4) slide aging; (5) slide brand; (6) “human” influence; and (7) sample size and fixation. Each of these issues was individually investigated to establish their influence on detachment. Targeted experiments were performed by varying section age, thickness, cleanliness, slide brand and age, and sample size and fixation. Finally, to investigate operator-dependent causes, sections were cut by different operators blinded to aim. The most important factors influencing section detachment were demonstrated to be: section thickness, slide aging, slide brand, “human” influence, and size and fixation of samples. The pre-analytical phase, including all the aforementioned issues, should be standardized within a quality assurance program. By adopting these recommendations, we obtained a 34% drop in section detachment. Although section detachment remains difficult to eradicate completely, many other influences can be addressed and corrected in any laboratory leading to an increase in efficiency and cost saving.

Seeds in the appendix: a ‘fruitful’ exploration

Our contribution aims at clarifying and underlining a possible finding which can pose an interesting twist in routine appendix diagnostics: seeds in the appendiceal lumen, their histological aspects and their differential diagnosis with parasites. We work in a training centre with a large referral practice for gastrointestinal pathology and often the most banal cases are those which pose problems to junior or non-expert pathologists. This short study aims at providing simple iconographic tables, which are not at the moment available either in publications or on the web, with the most frequent seeds encountered in our routine practice or sent for second opinion. The real importance of identifying seed type in histological sections, however is in forsensic pathology and forensic botany where the identification of seeds as stomach content may provide important clues for solving major crimes. This article is protected by copyright. All rights reserved.

Quality control in diagnostic immunohistochemistry: integrated on-slide positive controls

Standardization in immunohistochemistry is a priority in modern pathology and requires strict quality control. Cost containment has also become fundamental and auditing of all procedures must take into account both these principles. Positive controls must be routinely performed so that their positivity guarantees the appropriateness of the immunohistochemical procedure. The aim of this study is to develop a low cost (utilizing a punch biopsy—PB—tool) procedure to construct positive controls which can be integrated in the patient’s tissue slide. Sixteen frequently used control blocks were selected and multiple cylindrical samples were obtained using a 5-mm diameter punch biopsy tool, separately re-embedding them in single blocks. For each diagnostic immunoreaction requiring a positive control, an integrated PB-control section (cut from the appropriate PB-control block) was added to the top right corner of the diagnostic slide before immunostaining. This integrated control technique permitted a saving of 4.75% in total direct lab costs and proved to be technically feasible and reliable. Our proposal is easy to perform and within the reach of all pathology labs, requires easily available tools, its application costs is less than using external paired controls and ensures that a specific control for each slide is always available.

A Rare Polypoid Lesion of the Jejunum

An 86-year-old women was admitted to the emergency department for intestinal bleeding, and laboratory analysis revealed anemia. Virtual colonoscopy showed a thickening of the small intestinal bowel wall; abdominal computed tomography revealed a polypoid mass of about 16 mm in the small intestine. Jejunal resection was performed as an elective procedure. Approximately 30 cm of jejunum was resected, and a polypoid mass of 20 mm was observed on the antimesenteric aspect of the intestine. At histology, the polypoid lesion was predominantly submucosal and was composed of a proliferation of tubular structures lined by typical columnar and cuboidal cells, with evidence of mucin secretion but no goblet cells (Figure 1A). The overlying small intestinal mucosa was normal except for in focal areas where intestinal-type epithelium was replaced by lesional glands (Figure 1B). Submucosal glands were occasionally dilated and the stroma showed a proliferation of smooth muscle cells. Lesional glands expressed keratin 7, keratin 19, CA 19.9, MUC-6, and focally MUC-5A. Conversely, the overlying small intestine mucosa expressed keratin 20, CDX-2, and MUC-2 (Figure 2A-F). A diagnosis of jejunal adenomyoma was made. Benign polypoid lesions of the small intestine are very rare, and of these, adenomyoma represents less than 7%. Adenomyoma has been described along the entire small bowel with particular frequency in the periampullary region. Only 27 cases of adenomyoma of the small bowel have, up till now, been described and less than one third are jejunal. Immunohistochemistry shows a typical pancreatobiliary-type phenotype, both with regard to keratin expression (keratin 7, CA 19.9) and mucin production (MUC-5A and MUC-6). The overlying intestinal mucosa showed typical intestinal markers (keratin 20 positive, keratin 7 negative, CDX2 positive, MUC-2 positive). The pathogenesis of adenomyoma is still uncertain, and it is hypothesized to be either a form of hamartoma or an incomplete form of heterotopic pancreas. Although no pancreatic acinar component is normally found, the morphology of the glandular structures, keratin expression, and mucin-type production are suggestive of a pancreatic origin/heterotopia. 604737 IJSXXX10.1177/1066896915604737International Journal of Surgical PathologyPitto et al research-article2015