Thyroid papillary microcarcinoma. Is it really a pitfall of fine needle aspiration cytology?

OBJECTIVE: To assess the role of fine needle aspiration (FNA) of the thyroid in the diagnosis of papillary microcarcinoma. STUDY DESIGN: Eight cases of papillary microcarcinoma were diagnosed by fine needle aspiration. On histologic examination they were found to be adjacent to larger nodules of interest. The microcarcinomas were inadvertently sampled when sampling the larger, dominant nodules. RESULTS: None of the eight dominant nodules were papillary carcinoma; seven were benign lesions, and one was an angioinvasive Hürthle cell carcinoma. In three cases the microcarcinomas were situated within the capsule of a hyperplastic nodule. On histologic examination, five cases had multifocal microcarcinomas, with one case having multiple lymph node metastases. Based on the clinical findings and morphologic features, there were no definitive cytologic findings that could distinguish between "incidental" microcarcinoma and clinically significant papillary carcinoma. CONCLUSION: The detection of microcarcinoma by FNA should not be considered a false positive finding since the exact nature of the lesion cannot be determined until complete histologic evaluation reveals it to be truly incidental and clinically insignificant.     

The gray zone in breast fine needle aspiration cytology. How to report on it?

OBJECTIVE: To study the "gray zone" in breast fine needle aspiration cytology in which an unequivocal diagnosis cannot be reached with fine needle aspiration cytology findings. STUDY DESIGN: This study compared cytology and histopathology of 72 breast lesions in which an initial cytologic diagnosis of atypia was given. RESULTS: There were 36 benign (50%) and 36 malignant (50%) histologic biopsy cases in the cytologic atypia group. Anisonucleosis, chromatin and nuclear membrane irregularity, and presence of myoepithelial cells were significantly different in benign and malignant cases. CONCLUSION: The gray zone in breast fine needle aspiration cytology is a broad spectrum that changes from proliferative fibrocystic disease to sclerosing adenosis to malignancy. Diagnosing gray zone pathology as atypical in fine needle aspiration cytology causes no delay in treatment as excisional biopsy is recommended for all equivocal cases.     

Lymphangioleiomyomatosis. Is fine needle aspiration cytodiagnosis possible?

Lymphangioleiomyomatosis is a rare condition characterized by a proliferation of the smooth muscle cells, mainly in the lymphatic system, giving rise to blockage of the thoracic duct with chylothorax and chyloascites. This condition was seen in a 34-year-old woman with an abdominal tumor that was subjected to fine needle aspiration. The cytologic diagnosis of this neoplasm is difficult since the cellularity and the cytologic picture indicate malignancy. The organoid configuration together with the chylus formation gave an important clue to the correct diagnosis, which, however, was not made until after a biopsy was performed and the cytologic and histologic findings were combined. The cytologic, histologic and electron microscopic findings are presented.     

Diagnosis of lymphoma by image-guided needle biopsies: fine needle aspiration biopsy, core biopsy or both?

OBJECTIVE: To determine whether or not concurrent core biopsy adds to results obtained from image-guided fine needle aspiration biopsy (FNAB) in cases of lymphoma. STUDY DESIGN: Twenty-eight FNABs of lymphomas with adjuvant flow cytometry (FC) and concurrent core biopsy were evaluated retrospectively. In each case, completeness of diagnosis by FNAB, including phenotyping and grading, where appropriate, was reviewed. The contribution of core biopsy to the diagnosis in cases where FNAB did not render a complete diagnosis was assessed. Prognostic information not available from the FNAB but obtained from the core biopsy was also evaluated. RESULTS: FNAB with adjuvant FC gave a complete diagnosis, including phenotype and grade, where applicable, in 23 of 28 cases (82%). Core biopsy added to the diagnosis in 3 cases. In 1 case, large B-cell lymphoma was diagnosed on core biopsy when FNAB was unsatisfactory. In the other 2 cases, grade of follicle center cell lymphoma was higher on core biopsy than on FNAB. The addition of the information obtained by core biopsy to that obtained by FNAB raised the diagnostic accuracy to 93%. Core biopsy was used to assess nodularity, which could not be determined on FNAB. Core biopsy was also used to assess prognostic markers by immunohistochemistry (Ki-67 and p53); they were not available with FC. This was done in 11 cases when requested by the oncologist. CONCLUSION: FNAB with adjuvant FC is a useful technique for diagnosing and subtyping lymphomas. However, diagnosis and subclassification are often insufficient. Core biopsy material provides opportunity for obtaining additional diagnostic and prognostic information that may not be easily derived from the FNAB. This allows optimal treatment planning in patients for whom excisional biopsy is contraindicated.     

Computed tomography-guided fine needle aspiration of peripheral lung opacities. An initial diagnostic procedure?

OBJECTIVE: To evaluate the results of computed tomography (CT)-guided fine needle aspiration (FNA) cytology following negative fiberoptic bronchoscopy and sputum cytology. STUDY DESIGN: Retrospective study of 64 patients who underwent CT-guided needle aspiration of lung opacities over one year. Following a review of the CT studies, patients were selected according to image characteristics of a primary neoplasm and pleural effusion in cases with pleural lesions. The lesions were classified into three categories--intrapulmonary and peripheral pulmonary, pleuropulmonary and pleural--and were localized and aspirated under CT using a fine needle (22-23 gauge) for obtaining cellular material. Lesions diagnosed as benign on FNA cytology were followed by serial CT scans for a period of two years at six-month intervals. RESULTS: Thirty-nine of 64 (61%) lesions were diagnosed as malignant on FNA cytology and 25 of 64 (39%) as benign. There was one false negative case. There were no serious complications from the procedure. CONCLUSION: FNA under CT guidance may be applied as the initial procedure in the diagnosis of peripheral malignant pulmonary lesions, rendering a high diagnostic yield.     

Fine needle aspiration biopsy of azoospermic testes. Could it replace histologic biopsy?

OBJECTIVE: To evaluate the possibility of replacing histologic biopsy of azoospermic testes by fine needle aspiration (FNA) for diagnostic and management purposes. STUDY DESIGN: Twenty-seven patients were examined under general anesthesia, and 53 testes were biopsied by FNA. Fifty-four testes were biopsied for histologic examination. Histology and cytology of each testis were compared to assess the discrepancy or concordance between the diagnoses. RESULTS: Twenty-seven testes showed complete concordance of cytology and histology, and 13 testes showed a mild degree of discrepancy. A severe degree of discrepancy was seen in 13 testes. In the majority of discrepant cases, FNA biopsy diagnosis was more sensitive in detecting evidence of full or advanced maturation. In one case of discrepancy, the histologic finding was Sertoli cells only, and cytology revealed focal full maturation. In vitro fertilization using sperm from this case was successful. CONCLUSION: FNA biopsy of testes in azoospermia is a fast, reliable and minimally traumatic method. The prospects for utilizing FNA biopsy material in assisted and microassisted fertilization are promising.     

Preoperative fine needle aspiration cytology diagnosis of microcystic adenoma of the pancreas: fact or fiction? A report of 2 cases

BACKGROUND: Microcystic adenoma is an uncommon benign neoplasm involving the pancreas that usually affects older populations. These neoplasms often enlarge to significant sizes, causing symptoms of obstruction and discomfort. CASES: We report 2 cases of microcystic adenoma of the pancreas in which an accurate diagnosis could not be rendered on cytology material alone. Bench fine needle aspiration (FNA) biopsy performed on the resection specimen in one of the cases had a higher cellular yield because a different technique was used to prepare the slide. CONCLUSION: A preoperative diagnosis can be helpful in guiding the care of the patient, thereby increasing the importance of a diagnosis to distinguish between a benign vs. malignant process. These case reports demonstrate the difficulty of obtaining diagnostic cells in microcystic adenoma, highlight the use of FNA to increase cellular yield and emphasize the importance of correlating radiologic findings with aspiration of abundant watery fluid from cystic pancreatic masses to make a definitive diagnosis.     

Fine needle cytology--is aspiration suction necessary? A study of 100 masses in various sites

One hundred consecutive superficial mass lesions in various body sites were sampled by both conventional fine needle aspiration (FNA) and by a fine needle without the application of syringe suction. The latter technique is based on the principle of capillarity and may be termed "fine needle capillary" (FNC) sampling. The two sampling techniques were compared using five objective parameters: (1) the amount of diagnostic cellular material present, (2) the retention of appropriate architecture and cellular arrangement, (3) the degree of cellular degeneration, (4) the cellular trauma and (5) the volume of obscuring background blood and clots. There was no statistically significant difference between the efficacies of the two sampling techniques for any of the parameters studied. FNA sampling was diagnostic in a greater number of cases than was FNC sampling, but this difference was not statistically significant at a level of P = .05. When FNC sampling was diagnostic, it more frequently produced superior-quality material; conventional FNA, although diagnostic in a greater number of cases, mostly produced adequate, rather than superior-quality, material. This trend was not, however, statistically significant at a level of P = .05. These findings differ from those of previous studies (which have shown overall superiority of FNC sampling over conventional FNA sampling) and suggest that the technique of fine needle sampling employed for cytodiagnosis can be left to the personal preference of the operator.     

Fine needle aspiration of the thyroid: can an image processing system improve differentiation?

OBJECTIVE: To differentiate thyroid nodules by means of fine needle aspiration with subsequent computer-aided diagnosis. STUDY DESIGN: Fine needle aspiration biopsies obtained from 137 patients for whom histopathologic diagnosis was available were investigated: 16 hyperplastic nodules (12%), 39 adenomas (28%), 25 follicular thyroid carcinomas (18%), 19 follicular variants of papillary thyroid carcinoma (14%) and 38 papillary thyroid carcinomas (28%). From each stained specimen 100 cell scenes were scanned and analyzed, constituting a total of 62,325 cell images. RESULTS: All the entities described could be well discriminated from each other by automated image analysis methods. Both the diagnosis of tumor type and the differentiation between benign and malignant could be achieved with a sensitivity of .98. CONCLUSION: With only 7-10 calculated cell features (texture line analysis) and classification with decision trees, a tool for high-quality cell image diagnosis is available. Subtypes of cells characterized by the calculated features could be found in all the specimens and could be assigned to the malignancies with high statistical significance. The method increases the relevance of image processing as an additional diagnostic tool for cytologic examination of thyroid nodules.     

Behavioral diversity in populations of free-ranging chimpanzees in Africa: is it culture?

Behavioral differences exist among populations of wild chimpanzees (Pan troglodytes, Hominoidea) across Africa. Deciding if these are cross-cultural differences demands careful interpretation and rigorous scrutiny. Even standard patterns like social grooming may show variation in detail between neighboring populations. Some patterns of tool use, such as using hammers to crack nuts, also vary across far western Africa. At least 37 populations of free-ranging chimpanzees show tool use, and 14 show at least one habitual pattern of tool use. Regional differences exist among the three subspecies or geographical races of chimpanzees. Convincing empirical demonstration of social customs and traditions in non-human species is problematical, and even something so simple in principle as innovation is hard to show in practice. However, culture need not depend on imitation, teaching, or language, either in humans or in other species.     

Fine needle aspiration of borderline ovarian lesions. Is It useful?

Borderline ovarian tumors are a low grade form of epithelial ovarian carcinoma with a low rate of growth and a low potential to invade or metastasize. According to the new World Health Organization classification, these tumors are placed between clearly benign and obviously malignant tumors because they exhibit some, but not all, of the morphologic features of malignancy. For a distinction between borderline lesions and cystadenomas or carcinomas, 2 criteria are of the utmost importance: presence of nuclear atypia and absence of stromal invasion. The pathologic subtype ofperitoneal implants is probably one of the main prognosticfactors in patients with serous tumors of low malignant potential, while the prognostic value of micropapillary serous carcinoma in patients with noninvasive implants remains debatable. Although fine needle aspiration (FNA) is the most accurate diagnostic method in cytopathology, its value in the diagnosis of borderline lesions is limited, mainly because of its inability to establish the absence of stromal invasion. The diagnostic accuracy of RNA can be improved by supplementing cytologic examination with such diagnostic techniques as immunocytochemistry and cytometry.     

Limb regeneration in axolotl: is it superhealing?

The ability of axolotls to regenerate their limbs is almost legendary. In fact, urodeles such as the axolotl are the only vertebrates that can regenerate multiple structures like their limbs, jaws, tail, spinal cord, and skin (the list goes on) throughout their lives. It is therefore surprising to realize, although we have known of their regenerative potential for over 200 years, how little we understand the mechanisms behind this achievement of adult tissue morphogenesis. Many observations can be drawn between regeneration and other disciplines such as development and wound healing. In this review, we present new developments in functional analysis that will help to address the role of specific genes during the process of regeneration. We also present an analysis of the resemblance between wound healing and regeneration, and discuss whether axolotls are superhealers. A better understanding of these animals' regenerative capacity could lead to major benefits by providing regenerative medicine with directions on how to develop therapeutic approaches leading to regeneration in humans.     

Stability and value of male care for offspring: is it worth only half the trouble?

Models of parental investment often assume a trade-off for males between providing care and seeking additional mating opportunities. It is not obvious, however, how such additional matings should be accounted for in a consistent population model, because deserting males might increase their fertilization success at the cost of either caring males, other deserting males or both. Here, we present a game theory model that addresses all of these possibilities in a general way. In contrast to earlier work, we find that the source of deserting males' additional matings is irrelevant to the evolutionary stability of male care. We reject the claim that fitness gains through male care are intrinsically less valuable than those through desertion, and that the former must therefore be down-weighted by 1/2 when compared with the latter.     

Evolution of host specificity in fleas: is it directional and irreversible?

Evolutionary trends in the evolution of host specificity have been the focus of much discussion but little rigorous empirical testing. On the one hand, specialization is often presumed to lead irreversibly into evolutionary dead ends and little diversification; this would mean that generalists might evolve into specialists, but not vice versa. On the other hand, low host specificity may limit the risk of extinction and provide more immediate fitness benefits to parasites, such that selection may favour evolution toward a generalist strategy. Here, we test for directionality in the evolution of host specificity using a large data set and phylogenetic information on 297 species of fleas parasitic on small mammals. The analyses determined whether host specificity, measured both as the number of host species exploited and their taxonomic diversity, was related to clade rank of the flea species, or the number of branching events between an extant species and the root of the phylogenetic tree (i.e., the total path length from the root of the tree to the species). Based on regression analyses, we found positive relationships between the number of host species used and clade rank across all 297 species, as well as within one (Hystrichopsyllidae) of four large families and one of seven large genera investigated separately; in addition, we found a positive relationship between the taxonomic diversity of host species used and clade rank in another of the seven genera. These results suggest a slight evolutionary trend of decreasing host specificity. Using a much more conservative likelihood ratio test, however, a random walk, or null model, of evolution could not be discarded in favour of the directional trends in all cases mentioned above. Still, these results suggest that host specificity may have tended to decrease in many flea lineages, a process that could have been driven by the benefits of exploiting a wide range of host species.