Solitary epithelial cells in B cell gastric MALT lymphoma.

BACKGROUND: Gastric mucosa associated lymphoid tissue (MALT) lymphoma is a low grade B cell lymphoma histologically characterised by neoplastic B cells surrounding follicles in a marginal zone pattern and selectively infiltrating epithelium to form characteristic lymphoepithelial lesions. AIMS: To identify solitary epithelial cells in gastric MALT lymphoma and investigate their nature. METHODS: Anonymised endoscopic biopsies from eight B cell gastric MALT lymphomas and 10 control biopsies from chronic atrophic gastritis were selected. The numbers of solitary cytokeratin positive epithelial cells were assessed both semiquantitatively and quantitatively in immunostained sections. Chromogranin A expression was studied in sections consecutive to those stained for cytokeratin. RESULTS: Statistical analysis of the quantitative data confirmed that solitary epithelial cells were significantly more common in the lymphomas. The study of consecutive sections showed that the single cells express chromogranin A. CONCLUSIONS: The presence of solitary, cytokeratin positive epithelial cells within the neoplastic infiltrate is a characteristic feature of gastric B cell lymphoma. These solitary epithelial cells are of neuroendocrine origin.

Uterine tumour resembling an ovarian sex cord tumour.

Endometrial stromal sarcomas account for 0.25% of all uterine malignancies. These tumours were originally divided into low grade and high grade stromal sarcomas, but the recent World Health Organisation classification (2003) recognises low grade stromal sarcoma and undifferentiated endometrial sarcoma. Low grade sarcomas may exhibit other forms of differentiation, including smooth muscle and sex cord differentiation. In the latter form, the tumour contains epithelial-like or sex cord-like elements often with epithelioid appearance, arranged in nests, cords, trabeculae, solid, or tubular structures. If this element predominates, the tumour is considered to be a uterine tumour resembling ovarian sex cord tumour, and may cause diagnostic difficulties. This case report describes the histological and immunohistochemical features of a uterine stromal sarcoma showing exclusively a pattern reminiscent of ovarian sex cord tumour.

Squamous cell carcinoma arising in a tall cell papillary carcinoma of the thyroid.

Transformation of differentiated thyroid cancer into poorly differentiated carcinoma is rare. This report describes a case in which preoperative fine needle aspiration suggested a squamous cell carcinoma whereas needle core biopsy favoured an undifferentiated carcinoma of probable thyroid origin. Histology of the subsequent total thyroidectomy specimen revealed a biphasic tumour comprising areas of tall cell papillary carcinoma merging with moderately to poorly differentiated squamous cell carcinoma. The immunohistochemical findings are discussed in detail.

Specificity of lymphoreticular accumulation of prion protein for variant Creutzfeldt-Jakob disease.

BACKGROUND: Immunocytochemical accumulation of prion protein (PrP) in lymphoid tissues is a feature of variant Creutzfeldt-Jakob disease (vCJD) that has been used both to aid in the diagnosis of patients and as a basis of large scale screening studies to assess the prevalence of preclinical disease in the UK. However, the specificity of this approach is unknown. AIM: To assess the specificity of lymphoreticular accumulation of PrP for vCJD by examining a range of human diseases. METHODS: Paraffin wax embedded lymphoreticular tissues from patients with several reactive conditions (58 cases), tumours (27 cases), vCJD (54 cases), and other human prion diseases (56 cases) were assessed. PrP accumulation was assessed by immunocytochemistry using two different monoclonal anti-PrP antibodies and a sensitive detection system. RESULTS: All cases of vCJD showed widespread lymphoreticular accumulation of PrP; however, this was not seen in the other conditions examined. CONCLUSION: Lymphoreticular accumulation of PrP, as assessed by immunocytochemistry, appears to be a highly specific feature of vCJD.

[Helocobacter heilmannii (Gastrospirillum hominis)-associated gastritis: first reported cases in Hungary]. / Helicobacter heilmannii (Gastrospirillum hominis) asszociált gastritis: az elsö Magyarországon leírt esetek.

We found a tightly coiled bacterium, Helicobacter heilmannii that is distinct from Helicobacter pylori in the gastric mucosal biopsy of a 55-year-old man and a 30-year-old woman, both of whom had previous history of intermittent epigastric pain. The organisms were distributed in the antral mucosa, which was endoscopically interpreted as demonstrating chronic gastritis in one case, and being normal in the other. Histologically, the affected mucosa presented a mild chronic gastritis without activity and a moderate chronic gastritis with marker activity, respectively. The bacteria seen on haematoxylin eosin stained slides were strongly Giemsa positive, and were also visualized with Warthin-Starry stain. They were negative with the anti-Helicobacter pylori immunohistochemistry, although a few spots of staining could represent some cross reaction. Electron microscopy revealed fragments of bacterium, with its characteristic spiral shape and length of 4-7 mm in the plane of the section. One of the patient was treated medically and the control examination revealed normal antral mucosa without spiral bacteria. Detection of these organisms may provide a new insight into the pathogenesis of human gastritis.