A study was carried out to test the accuracy and consistency of veterinary pathologists, not specialists in hematopathology, in applying the World Health Organization (WHO) system of classification of canine lymphomas. This study represents an initiative of the ACVP Oncology Committee, and the classification has been endorsed by the World Small Animal Veterinary Association (WASVA). Tissue biopsies from cases of canine lymphoma were received from veterinary oncologists, and a study by pathologists given only signalment was carried out on 300 cases. Twenty pathologists reviewed these 300 cases with each required to choose a diagnosis from a list of 43 B and T cell lymphomas. Three of the 20 were hematopathologists who determined the consensus diagnosis for each case. The 17 who formed the test group were experienced but not specialists in hematopathology, and most were diplomates of the American or European Colleges of Veterinary Pathology. The overall accuracy of the 17 pathologists on the 300 cases was 83%. When the analysis was limited to the 6 most common diagnoses, containing 80% of all cases, accuracy rose to 87%. In a test of reproducibility enabled by reintroducing 5% of cases entered under a different identity, the overall agreement between the first and second diagnosis ranged from 40 to 87%. The statistical review included 43,000 data points for each of the 20 pathologists.

Epidermal growth factor receptor (EGFR) overexpression occurs in a significant percentage of cases of glioblastoma multiforme (GBM), and amplification has been found in approximately 40% of these neoplasms. Controversy exists as to the prognostic significance of EGFR gene amplification: some reports have indicated that amplification is associated with a poor prognosis, while other authors have reported no relationship between gene amplification and prognosis. Some reports have found a poor prognosis to be associated with amplification of the EGFR gene in patients of all ages with GBM, while other authors have found EGFR amplification to be an independent predictor of prolonged survival in patients with GBM who are older than 60 years of age. The authors studied a series of 34 specimens (32 patients) with histologically proven GBM by immunohistochemistry for the presence of EGFR overexpression and by fluorescence in situ hybridization (FISH) for gene amplification of the EGFR gene. Results of these studies and data on patient age, sex, functional status, therapy, and survival were correlated to determine which variables were predictive of survival. p53 expression was also determined by immunohistochemistry and correlated with the other variables and survival.

We reviewed fine-needle aspiration (FNA) samples of metastatic tumor in the pancreas from nonhematologic neoplasms over a 5-year period. In 1,050 total procedures, 20 metastases were diagnosed: 9 renal-cell carcinomas (RCCs), 3 melanomas, 2 pulmonary small-cell carcinomas, 2 breast carcinomas, 1 prostate carcinoma, 1 colon adenocarcinoma, 1 pulmonary squamous-cell carcinoma, and 1 gastrointestinal stromal tumor. A wide range of latency from primary diagnosis was noted; the longest was RCC at 12.6 years (range, 5-28). Sites of involvement were: 13 heads, 4 bodies, and 3 tails. Eighteen cases presented as a solitary mass. The average size was 4.7 cm (range, 1.5-9.8), and a case of RCC (9.8 cm) was the largest. In seven cases, the clinical and radiographic impression was of a pancreatic primary. We conclude that metastases to the pancreas are rarely diagnosed by FNA and may clinically mimic a pancreatic primary.

Fine-needle aspiration (FNA) is a popular method for evaluating pancreatic lesions. There is considerable literature on FNA evaluation of primary pancreatic carcinomas, but few studies address the FNA diagnosis of primary pancreatic lymphoma. We reviewed 14 cases of atypical lymphoid processes diagnosed by FNA during a 5-year period, constituting 1.3% of a total of 1,050 pancreatic FNA cases. The diagnoses were as follows: 6 large B-cell lymphomas, 4 follicular lymphomas, 3 suggestive of lymphoma, and 1 unclassified B-cell lymphoma. Lymphoid neoplasms manifested in older people (mean age, 64.7 years) as a solitary mass in the pancreatic head, mimicking primary carcinoma. Clonality was confirmed by flow cytometry in 11 cases and immunohistochemical analysis on cell block material in 2. Obtaining diagnostic material often required several passes (average, 3.9 passes; range, 1-8 passes). We conclude that primary pancreatic lymphomas rarely are diagnosed by FNA, tend to be high grade, and clinically and radiographically might mimic primary carcinoma.

Abdominal fat pad fine‐needle aspiration biopsy (FNAB) is considered the method of choice for confirmation of systemic amyloidosis. Due to our impression that positive results are rare in our FNA service, we retrospectively analyzed our results. Forty‐five samples collected from 45 patients over 3 yr were reviewed. Of the 7 patients with positive Congo red‐stained FNAB specimens, all 7 (100%) had documented amyloidosis. Of the 33 patients with negative Congo red fat samples, 28 (85%) were disease‐free. Of the 5 patients with inadequate samples, 2 (40%) were later diagnosed with disease. We demonstrate excellent specificity (100%). The positive predictive value, documented in only a few previous studies, is likewise excellent (100%). Sensitivity is low (58%) and inadequacy is high (11%). Improvement in technique, such as concurrent cell block preparation, may help avoid inadequate specimens. Difficulties in confirming amyloidosis also include interpretation of the Congo red stain (pale‐stained amyloid fibrils and collagen birefringence). Diagn. Cytopathol. 2001;24:181–185. © 2001 Wiley‐Liss, Inc.

Thyroid carcinoma showing thymus-like differentiation (CASTLE) is a rare tumor of the thyroid gland or adjacent soft tissues of the neck. Given the comparatively good prognosis of CASTLE, it is crucial to distinguish this neoplasm from other more aggressive thyroid neoplasms that can have similar or overlapping cytomorphological features. However, there is little information about the cytomorphology of CASTLE available in the literature. Here we report the cytomorphology and histology of thyroid CASTLE in a 52-year-old woman and present a review of the literature.

We retrospectively reviewed 74 fine-needle aspiration (FNA) cases of presumptive non-Hodgkin lymphoma (NHL). All the cases had cytology and core-needle biopsy and 53 cases had concurrent flow cytometric analysis. FNA (cytology and flow cytometry) and core-needle biopsy were evaluated independently. FNA was diagnostic of diffuse large B-cell lymphoma (DLBL) in 25% (13/53) of cases and small B-cell NHL in 15% (8/53) of cases, whereas core-needle biopsy was diagnostic of DLBL in 37% (27/74) of cases and small B-cell NHL in 8% (6/74) of cases. Subclassification of small B-cell NHL was reached in 3/6 cases by core-needle biopsy. Insufficient cases were observed in both FNA (47%; 25/53) and core-needle biopsy (28%; 21/74) groups. With the combination of FNA and core-needle biopsy, diagnostic cases of DLBL increased to 43% (32/74) and insufficient samples were reduced to 16% (12/74). There was no clear advantage in the diagnosis and classification of small B-cell NHL by adding core-needle biopsy to FNA (14%; 10/74). We conclude that core-needle biopsy is a useful adjunct to FNA in the diagnosis of DLBL and shall be encouraged. In small B-cell NHL, core-needle biopsy does not add to the diagnostic ability of FNA. Cases insufficient for diagnosis may be seen in both core-needle biopsy and FNA. A combined approach reduces the number of insufficient cases and is recommended in routine FNA practice.

The AFFIRM Study enrolled 4060 predominantly elderly patients with atrial fibrillation to compare ventricular rate control with rhythm control. The patients in the AFFIRM Study were representative of patients at high risk for complications from atrial fibrillation, which indicates that the results of this large clinical trial will be relevant to patient care.