Fine needle aspiration biopsy of Hashimoto's thyroiditis. Sources of diagnostic error.

OBJECTIVE: To determine the accuracy of cytologic interpretation in the diagnosis of Hashimoto's thyroiditis (HT). STUDY DESIGN: At Ottawa Hospital from 1987 to 1994, 1,638 fine needle aspiration biopsies (FNABs) from thyroid were performed. HT was suggested in 184 FNAB samples taken from 157 patients. Of the 184 aspirates diagnosed with HT, 39 had corresponding surgical specimens taken from 31 patients. A retrospective review of these FNABs and surgical pathology slides formed the basis of this study. RESULTS: In 27 (69%) aspirates, HT was diagnosed on both the FNAB and surgical specimens. In 10 of 27 FNABs an associated lesion was not sampled by FNAB. In four of these 10 aspirates some of the cellular features of HT were misinterpreted, and the possibility of an associated neoplasm could not be ruled out. This resulted in four false positive diagnoses. In 12 (31%) FNABs from nine patients, the cytologic diagnosis of HT was not confirmed histologically. These cases included five Hürthle cell adenomas and one case each of follicular adenoma, nodular goiter, macrofollicular adenoma and malignant lymphoma. This resulted in five false negative diagnoses. CONCLUSION: These results support the value of FNAB in the diagnosis of HT. The presence of hyperplastic follicular cells on FNAB samples from HT may mimic a follicular neoplasm and result in a false positive interpretation. Adequate sampling of the thyroid is important, particularly when there is an associated lesion. The diagnosis of lymphocytic thyroiditis should not be made when only a few lymphocytes are present. Finally, pleomorphic Hürthle cells may be present in aspirates from Hürthle cell neoplasms and underdiagnosed as HT, especially when they are associated with a few lymphocytes.     

Fine needle aspiration biopsy of vertebral lesions

OBJECTIVE: To evaluate the accuracy of fine needle aspiration biopsy (FNAB) in the diagnosis of vertebral lesions. STUDY DESIGN: Eighty-nine FNAB cases of vertebral lesions from January 1996 to December 2001 were retrieved from the Allegheny General Hospital laboratory information system. The cases were reviewed and correlated with clinical findings, including previous clinical history, primary site of malignancy and final pathologic diagnosis. RESULTS: ENAB diagnoses were malignant in 43 cases, benign in 35, suspicious in 1, unsatisfactory in 7 and false negative in 3. Previous clinical history included malignancy (37 patients), osteomyelitis and systemic disease (11), and nonspecific or no history (41). In 34 cases (38.2%) both aspirates and core biopsies were available, and the diagnoses correlated in 29/34 cases (85%). Surgical or core biopsies in the unsatisfactory/suspicious group showed malignancy in 4 cases (50%). The sensitivity of FNAB of vertebral lesions was 96%, specificity 100%, positive predictive value 100% and negative predictive value 92%, with no false positive cases. CONCLUSION: FNAB of vertebral lesions is an effective, sensitive and specific procedure in the diagnostic workup of a patient with or without a prior history of malignancy. Surgical pathology examination, including core biopsies of unsatisfactory or suspicious lesions, can further improve the diagnostic yield.     

Fine needle aspiration biopsy of intramammary neurilemoma

A case of benign neurilemoma (schwannoma) arising in the breast is presented, including the fine needle aspiration (FNA) biopsy findings. The aspirate yielded a cellular smear composed of clusters of spindle-shaped cells showing minimal atypia. The absence of mitotic figures and breast epithelium suggested a benign neoplasm. The final diagnosis was established on the excised mass by histopathologic study and the use of special stains. The utility and pitfalls of FNA biopsy in diagnosing this rare entity are discussed.     

Fine needle aspiration biopsy of hepatic focal fatty change. A report of two cases

BACKGROUND: In rare instances, hepatic steatosis produces a circumscribed, nodular lesion described as focal fatty liver change (FFLC). The ultrasonographic and computed tomographic patterns are those of an isointense or hyperechoic nodule, sometimes simultating metastasis. CASES: Fine needle aspiration biopsy was performed under ultrasonographic control in two men aged 65 and 67 years who had previously undergone emicolectomy and gastrectomy for adenocarcinoma. Routine hepatic ultrasound showed solitary nodules, of 3 and 4 cm in diameter. The microscopic patterns were similar and highly cellular in both cases. Cells were isolated or organized in sheets and characterized by large, intracytoplasmic, clear vacuoles that displaced nuclei to the periphery of the cells, flattening them against the cytoplasmic membrane and giving these cells a signet-ring appearance. Nuclei were generally round and nucleolated or dense and hyperchromatic when flattened onto the cytoplasmic membrane. Normal hepatocytes were interspersed in the background, and in some areas of the slides hepatocytes with one or more small intracytoplasmic vacuoles with cytologic features intermediate between those of vacuolated cells and normal hepatocytes were present. Digested periodic acid-Schiff staining, performed on destained, fixed smears, gave negative results. The cytologic diagnosis was FFLC. Clinical and echographic follow-up confirmed the cytologic diagnosis. CONCLUSION: The ultrasonographic and microscopic features of FFLC may mimic those of metastasis. A proper cytologic diagnosis may contribute to the diagnostic workup of these rare lesions.     

Fine needle aspiration biopsy in uveal melanoma

Fine needle aspiration (FNA) biopsies were performed in a series of patients with uveal tumors. Cytopathologic examination established the correct diagnosis in 26 of 29 uveal melanomas. FNA biopsy was able to exclude the diagnosis of a malignant neoplasm in five nonmelanoma tumefactions. Histologic and FNA cytologic typing of melanomas as epithelioid or predominantly spindle cell showed good agreement, with the same classifications made in 14 of 18 cases. FNA biopsy specimens also proved to be adequate for DNA-content and cell-cycling studies. The cessation of cell cycling in successfully irradiated melanomas may be useful in establishing the postradiation status of tumors that have questionable growths after therapy, as was shown using FNA samples in three such cases in this study. The results of this study show that FNA biopsy is a useful diagnostic adjunct in patients with atypical lesions that require therapy.     

Fine needle aspiration biopsy of orbital meningioma. Report of a case

A case of orbital neoformation in a 28-year-old man is described. The cytohistologic diagnosis on fine needle aspiration biopsy specimens was meningioma; this was later confirmed by histologic study of surgical fragments. The cytohistologic features of the aspirated material (nuclear pseudoinclusions, psammoma bodies and cells arranged in whorls) allowed a rapid, reliable, ambulatory diagnosis to be formulated with an advantageous cost/benefit ratio.     

Fine needle aspiration biopsy cytology of renal oncocytoma

The cytologic appearance of cells in fine needle aspiration biopsies of two cases of well-differentiated renal oncocytoma (grade 1) and one case of moderately well differentiated renal oncocytoma (grade 2) is presented. In grade 1 renal oncocytoma, the tumor cells were seen mainly singly or in small clusters; they were round or polygonal, with abundant granular and eosinophilic cytoplasm and small, regular, round, hyperchromatic nuclei. Aspirated cells from the grade 2 renal oncocytoma were seen mainly in large sheets. These cells were polygonal, with eosinophilic, granular cytoplasm and slightly irregular vesicular nuclei with prominent nucleoli.     

Fine needle aspiration biopsy of precursor B-cell lymphoblastic lymphoma presenting as a sacral mass. A case report

BACKGROUND: Lymphoblastic lymphoma (LBL) is a high grade, aggressive neoplasm, usually presenting in children and young adults. Precursor B-cell LBL is uncommon and may present with cutaneous or, less likely, bone lesions. This case represents the first reported presentation of LBL as a sacral lesion and was only the second fine needle aspiration biopsy (FNAB) of LBL presenting as a bony mass. CASE: A 50-year-old man presented with a 3-month history of a 7 x 5 x 4-cm mass in the sacral region. The mass was radiologically described as an expansile one with lytic bone destruction. Diagnosis of a chordoma was radiologically favored. Computed tomography (CT)-guided FNAB, with flow cytometry and cytochemical staining, was used to make the diagnosis of precursor B-cell LBL. CONCLUSION: FNAB was instrumental in reaching this unusual diagnosis in a patient who was free of disease after chemotherapy.     

Fine needle aspiration biopsy in the diagnosis of intrathoracic masses.

During a 3.5-year period (January 1, 1987, to June 30, 1990) 420 percutaneous fine needle aspiration (FNA) biopsies were performed on 390 patients (309 males, 81 females) suffering from one or more intrathoracic, radiologically visible lesions. Aspirations were carried out using 21- or 23-gauge Chiba needles under fluoroscopic or computed tomographic control. The aspirates were used to make minibiopsies and cytologic smears. Diagnosis was possible in 373 cases (95.64%): on the first pass in 344 cases, on the second in 28 cases and on the third in 1. In 17 cases (4.36%) the aspirate was inadequate for diagnosis. There were complications in 10 cases (2.56%) (9 pneumothorax and 1 hemophtysis) requiring intensive care. The 373 percutaneous FNA biopsy diagnoses included 256 malignant tumors (68.63%), of which 234 were primary and 22 were secondary, and 117 benign lesions (31.37%), 5 of them neoplastic and 112 nonneoplastic. Three hundred two of 373 percutaneous FNA biopsy diagnoses were followed (80.96%). One hundred twenty-three follow-ups were histologic (40.73%), including secondary tumors, which could be compared with the primary histotype. Twenty-eight follow-ups were cytologic (9.27%), and 151 were clinical (50.00%), using progression of the disease or the beginning of chemoradiotherapy as a criterion for malignancy and a stable condition or regression of the lesion with nononcologic medical treatment as a criterion for benignity. Percutaneous FNA biopsy diagnoses were confirmed in 288 cases (221 true positives and 67 true negatives) and unconfirmed in 14 (1 false positive and 13 false negatives). Specificity, sensitivity, negative predictive value, positive predictive value and total diagnostic accuracy were, respectively, 98.52, 94.44, 83.75, 99.54 and 95.36%. The histologic typing accuracy of percutaneous FNA biopsy on 70 specimens of surgically removed malignant epithelial neoplasias was 70.00%. These results confirm that percutaneous FNA biopsy is a reliable method of diagnosing intrathoracic masses and reduces the need for diagnostic thoracotomy.     

Fine needle aspiration biopsy of intraparotid schwannoma. A case report

BACKGROUND: Intraparotid schwannoma of the salivary gland is a rare entity. Review of the literature revealed one previous report describing its cytologic features. CASE: A 22-year-old man had a slowly growing, painless mass in the left parotid gland. Fine needle aspiration biopsy, performed prior to surgical excision, showed several tissue fragments consisting of uniform, spindle-shaped neoplastic cells with cigar-shaped nuclei and scant, ill-defined cytoplasm. Some of the neoplastic cells were clustered in typical arrangements of Verocay bodies. In addition, lymphocytes and foamy histiocytes were found. A diagnosis of schwannoma was made. Pathologic evaluation of the resected parotid mass supported the diagnosis. CONCLUSION: The diagnosis of intraparotid schwannoma can be made by examining cytologic material containing the characteristic Verocay bodies. The correct cytologic diagnosis of this entity helps to rule out morphologically similar primary salivary gland neoplasms and thereby permits the appropriate surgical procedure to ensue.     

Myoepithelioma of the salivary glands. Fine needle aspiration biopsy findings

OBJECTIVE: To evaluate the cytologic findings and pitfalls in the diagnosis of myoepithelioma of the salivary glands. STUDY DESIGN: Smears from 7 cases of myoepithelioma of the salivary glands, 3 plasmacytoid, 2 spindle and 2 mixed types, all histologically confirmed, were evaluated with special attention to cytologic features that may be helpful for the diagnosis. RESULTS: A correct cytologic diagnosis was not made in any of the cases. Three were diagnosed as plasmacytomas or cellular pleomorphic adenomas, 2 as benign spindle cell tumors and 2 as cellular pleomorphic adenomas. Mitoses and marked pleomorphism were absent. Nuclear striations were noted frequently. CONCLUSION: Diagnosis of myoepithelioma was difficult on fine needle aspiration smears. Nuclear striations (zebra lines) were noted in 5 cases. This finding is not reported in previously published papers.     

Fine needle aspiration biopsy diagnosis of mucoepidermoid carcinoma. Statistical analysis

Fine needle aspiration (FNA) biopsy is an increasingly popular method for the evaluation of salivary gland tumors. Of the common salivary gland tumors, mucoepidermoid carcinoma is probably the most difficult to diagnose accurately by this means. A series of 96 FNA biopsy specimens of salivary gland masses, including 34 mucoepidermoid carcinomas, 51 other benign and malignant neoplasms, 7 nonneoplastic lesions and 4 normal salivary glands, were analyzed in order to identify the most useful criteria for diagnosing mucoepidermoid carcinoma. Thirteen cytologic criteria were evaluated in the FNA specimens, and a stepwise logistic regression analysis was performed. The three cytologic features selected as most predictive of mucoepidermoid carcinoma were intermediate cells, squamous cells and overlapping epithelial groups. Using these three features together, the sensitivity and specificity of accurately diagnosing mucoepidermoid carcinoma were 97% and 100%, respectively.     

Fine needle aspiration biopsy of epithelioid angiomyolipoma. A case report

BACKGROUND: Epithelioid angiomyolipoma (AMYL) is a variant of angiomyolipoma characterized by sheets of epithelioid cells that may mimic renal cell carcinoma. This is the first report describing the fine needle aspiration biopsy features of this lesion. CASE: A 47-year-old man with a history of epithelioid angiomyolipoma of the kidney treated with nephrectomy nine months previously presented with a recurrent retroperitoneal mass and multiple nodular liver lesions. Fine needle aspiration biopsy of one of the liver lesions showed fragments and sheets of noncohesive epithelioid cells with thin cytoplasm, markedly atypical nuclei, and scattered bizarre and multinucleated forms. The epithelioid cells focally expressed HMB-45 and were nonimmunoreactive, with epithelial markers. CONCLUSION: Epithelioid AMYL may pose differential diagnostic problems with high grade carcinoma, especially renal cell, hepatocellular and metastatic carcinoma. An awareness of this entity and its characteristic cytologic features and immunoreactivity with HMB-45 is helpful in its identification.     

Fine needle aspiration biopsy of hepatocellular carcinoma. Some unusual features.

The cytologic features of fine needle aspiration smears from 28 hepatocellular carcinomas (HCC) were reviewed. All aspirations except one were guided. There were 14 well-, 11 moderately and 3 poorly differentiated HCC. The better-differentiated HCC were characterized by similarity of the tumor cells to hepatocytes (83%), cohesive cell clusters with a trabecular arrangement (72%) and presence of sinusoidal endothelial cells (66%). Other features included bile production (38%), atypical hepatocytic naked nuclei (52%), acinar formation (31%), intracytoplasmic vacuoles (14%) and abnormal vascular patterns (14%). Poorly differentiated HCC showed dyshesive pleomorphic cells. Unusual cytologic features from a well-differentiated HCC with fatty change and an HCC with a prominent acinar component are described. The identification of fatty change in dissociated well-differentiated hepatocytes or cytologic features suggestive of an adenocarcinoma do not preclude the diagnosis of HCC. The usefulness of cell blocks is emphasized.