Fine-needle aspiration of fibrous dysplasia of bone: a worthwhile endeavor or not?

Fine-needle aspiration (FNA) is a minimally invasive technique which is enjoying ever-increasing popularity in the initial diagnosis of many pathologic processes. However, FNA diagnosis of neoplasms occurring within bones is less commonly employed and is not the preferred method in some types of bony lesions. Fibrous dysplasia is a primary neoplasm of bone for which it is not yet clear whether FNA can reliably yield adequate diagnostic material. Review of data from 82 cases of fibrous dysplasia diagnosed between 1990 and 2006 yielded six cases, in which diagnosis was initially attempted by FNA prior to open biopsy and surgical resection. Corresponding cytologic, histologic, and imaging characteristics of the cases were reviewed. Of the six cases in which initial diagnosis was attempted by FNA, only two of six (33%) yielded adequate diagnostic material. Smears of aspirated material in all cases contained nonspecific elements, including fragments of benign host bone and cartilage, bland stromal cells, adipocytes, blood, and debris. Importantly, the two positive FNA cases were dependent on the concurrent core needle biopsy (all smears of aspirate material were nondiagnostic). Even with image guidance, FNA is insufficient to obtain diagnostic material for cases of suspected fibrous dysplasia of bone. Core needle biopsy at least is recommended to obtain adequate material, and to reduce the risk of misdiagnosis due to sampling error.

Molecular diagnostic testing as an adjunct to morphologic evaluation of pancreatic ductal system brushings: potential augmentation for diagnostic sensitivity.

Malignancies arising from the pancreatic and biliary ductal systems present the gastroenterologist and pathologist with diagnostic challenges. Tumors of the pancreatic and/or biliary ductal system may present as either duct strictures or mass lesions. When lesions present as strictures without associated demonstrable masses, brushing cytology may represent the only reasonable diagnostic technique aside from open biopsy. Diagnostic sensitivities for brushing cytology have ranged from 18 to 90%. Positive diagnoses of malignancy are of great clinical value but a negative result is of relatively little clinical aid when the radiographic or clinical findings are suspicious for a malignancy.A variety of techniques have been used in an attempt to improve diagnostic sensitivity for brushing cytology. These have included immunohistochemistry and various molecular diagnostic techniques. Using the high resolution melting curve technique, we performed mutational analysis on 20 bile duct brushing specimens for mutations in p53, K-ras, BRAF, and EGFR genes. Eleven specimens had corresponding surgical specimens, which were similarly analyzed. Our series included twelve adenocarcinomas, one islet cell tumor, one case of dysplasia, and six benign cases. K-ras mutations were found in cytology specimens of 3 out of 12 malignancies. No EGFR or B-raf mutations were detected and only a single p53 mutation in an adenocarcinoma was detected in the corresponding cytology specimen. No mutations were detected in benign lesions or in the dysplasia. Only 8% of specimens from adenocarcinomas had p53 mutations and only 33% of cases had K-ras mutations. Mutational analysis did not appear to improve the cytologic detection of adenocarcinoma by bile duct brushings.