No abstract

Acinar cell carcinoma is a rare malignant epithelial neoplasm with predominantly exocrine acinar differentiation and is seen primarily in older men (mean age, 62 years). The presenting symptoms are usually non-specific, and jaundice is often not present. Symptoms relating to the overproduction and release of lipase into the circulation are present in 10-15% of patients. Characteristic cytomorphologic features include a population of cells with minimal pleomorphism, eccentrically placed nuclei with a single prominent nucleoli and moderate hyperchromasia. The cytoplasm is finely granular, and the background may contain granular debris secondary to cytolysis. A significant proportion of the cases also have a minor neuroendocrine component or scattered neuroendocrine cells. Approximately 50% of patients have metastatic disease at presentation, often restricted to the regional lymph nodes and liver. The prognosis is poor, only slightly better than that of pancreatic ductal adenocarcinoma.

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase demonstrating activating mutations in several malignancies including a subset (1-5%) of non-small cell lung carcinomas (NSCLC). Prior work examining, the histologic features of these tumors found a spectrum of findings, notably a solid/acinar pattern, as well as a mucinous cribriform pattern. We present the first study to date describing the cytomorphology of NSCLC harboring ALK rearrangements. A retrospective database search was conducted to identify cytologic specimens of NSCLC demonstrating ALK rearrangement. Cytogenetic analysis was performed with fluorescence in situ hybridization. A total of 12 patients were identified, 10 with available material. Cellular morphology and smear background was evaluated in the study group, as well as control cases lacking ALK rearrangement. A total of 25 specimens from 10 patients were obtained. Five patients never smoked, and four patients had a remote smoking history. ALK rearrangements were identified in cells with unique cytologic characteristics. All cases demonstrated moderate to poor differentiation with a predominance of single cells showing anisonucleosis and frequent intracytoplasmic neutrophils. The control cases showed cells with smaller, less pleomorphic nuclei, and smaller nucleoli with more clusters/tissue fragments. Several unique cytomorphologic features were consistently identified in the study population relative to the control population and include a prominence of single, markedly enlarged tumor cells with plasmacytoid features and anisonucleosis, as well as intracytoplasmic neutrophils. Larger studies are warranted to confirm our preliminary findings, as these features may help establish a more cost-effective means to select patients being tested for ALK mutational analysis.

Aim  Colonoscopy to detect and remove polyps has contributed to a reduction in colorectal carcinoma. Three‐year follow up is recommended for patients considered to be at high risk (at least three adenomas, adenoma ≥ 1 cm, villous or high‐grade features). Our study focused on patients diagnosed with high‐grade dysplasia with regard to initial management and follow up. Method  A search of patients who had had endoscopic removal of a high‐grade adenoma was carried out. Patients with the following were excluded: follow up of < 1 year, polyposis syndromes, prior colon cancer and a diagnosis of adenocarcinoma within 6 months following initial diagnosis. Results  Eighty‐three patients treated between 1999 and 2007 for high‐grade dysplasia (HGD) in a colorectal adenoma were identified. Over a median follow‐up period of 4 years, 53 (64%) developed further adenomatous polyps. Among these, 7% had an adenoma with HGD or an adenocarcinoma. In all these patients, the initial high‐grade adenoma was > 1 cm in diameter. Initial follow‐up colonoscopy was performed on average 7 months following the initial diagnosis. Ten per cent of patients underwent prophylactic segmental resection, and 6% received argon laser therapy. Conclusion  The study demonstrates that patients who have a colorectal adenoma > 1 cm with HGD may be at high risk of developing further adenomas with HGD or carcinoma. Close follow up is warranted.

Acinar cell carcinoma of the pancreas is rare, accounting for less than 1% of carcinomas arising in the exocrine pancreas. Patients are typically between the fifth and seventh decade of life and show a 2:1 male predominance. Symptoms tend to be nonspecific, and approximately 50% of the patients have metastases at the time of presentation. There have been recent case reports of acinar cell carcinoma showing both intraductal and/or papillary patterns of growth that could potentially be mistaken for intraductal neoplasia. The cases reported up to date presented as solitary nodules. The authors describe the first case of acinar cell carcinoma with both intraductal and tubuloglandular growth diffusely involving the pancreas. In addition, the authors review the published cases reporting acinar cell carcinoma with intraductal and/or papillary growth patterns.