Fine Needle Aspiration Cytology Examination Research Articles

Diagnostic value and health economic evaluation of ultrasound-combined fine-needle aspiration cytology in primary breast cancer

To explore the diagnostic value and health economic evaluation of ultrasound-combined fine-needle aspiration cytology for axillary lymph node status in breast cancer. We reviewed retrospectively collected the data from 2503 cases of biopsy-proved breast cancer (T0-2) at our breast center between May 2005 and June 2010. The diagnostic fees of ultrasound-combined fine-needle aspiration cytology and clinical examination were calculated and assessed with cost-minimization analysis. Ultrasound-combined fine-needle aspiration cytology prevented 10.9 percent of the patients with positive clinical findings from unnecessary sentinel lymph node biopsy and achieved a saving of 155.55 RMB per patient. However, only 29.4 percent of the cases were diagnosed with ultrasonographic abnormal axillary nodes. Ultrasound-combined fine-needle aspiration cytology has great application values. The ultrasonic diagnostic criteria of abnormal axillary nodes should be loosened.

Diagnostic Accuracy of Ultrasonograph Guided Fine-needle Aspiration Cytologic in Staging of Axillary Lymph Node Metastasis in Breast Cancer Patients: a Meta-analysis

To evaluate the diagnostic accuracy of ultrasonograph and fine-needle aspiration cytologic examination (USG-FNAC) in the staging of axillary lymph node metastasis in breast cancer patients. We conducted an electronic search of the literature addressing the performance of USG-FNAC in diagnosis of axillary lymph node metastasis in databases such as Pubmed, Medline, Embase, Ovid and Cochrane library. We introduced a series of diagnostic test indices to evaluate the performance of USG-FNAC by the random effect model (REM), including sensitivity, specificity, likelihood ratios, and diagnostic odds ratios and area under the curve (AUC). A total of 20 studies including 1371 cases and 1289 controls were identified. The pooled sensitivity was determined to be 0.66 (95% CI 0.64-0.69), specificity 0.98 (95% CI 0.98-0.99), positive likelihood ratio 22.7 (95% CI 15.0-34.49), negative likelihood ratio 0.32 (95% CI 0.25-0.41), diagnostic OR 84.2 (95% CI 53.3-133.0). Due to the marginal threshold effect found in some indices of diagnostic validity, we used a summary SROC curve to aggregate data, and obtained a symmetrical curve with an AUC of 0.942. The results of this meta-analysis indicated that the USG-FNAC techniques have acceptable diagnostic validity indices and can be used for early staging of axillary lymph node in breast cancer patients.

Primary lingual tuberculosis, a rare case report

Sir, Lingual tubercular lesions are rare occurrences even in endemic countries like India. The lesions can present in a variety of appearances. They may masquerade as vascular malformations or malignant neoplasm clinically. Cases of lingual tuberculosis have been described from 1888 [1]. There have been occasional reports of lingual tuberculosis since then [2,3]. The clinical diagnosis is often difficult if not impossible as it is rare to suspect especially if it presents as a diffuse swelling. Most often, the diagnosis is made either by fine needle aspiration cytology or histopathological examination of a biopsy from the lesion. In this case, we present a patient who initially complained of a lingual swelling since 3 years. It had been gradually increasing in size and had occasionally ulcerated with minimal bloody discharge. The swelling was over the dorsal aspect of tongue and measured around 2.5x2.5cms in size (Fig. 1). It was firm in consistency with some areas being harder. There were no palpable cervical lymph nodes. Clinically a diagnosis of lymphatic malformation was made and excision biopsy was done (Fig. 2). Histopathological examination revealed numerous caseating epithelioid and giant cells granulomata, containing scanty acid fast bacilli. A final histopathological diagnosis of tuberculous lesion was later made and was supported by a positive PPD test and Mycobacterial culture from a sputum specimen. The patient was started on antituberculous therapy and follow up showed good initial response. Many believe that the rarity of oral tuberculosis is due to the continuous cleansing of the oral mucosa by saliva, the presence of a variable normal flora in addition to the presence of submucosal antibodies which gives the buccal mucosa a normal resistance [4]. The case differs from previously reported cases because the patient presented with a nodular and tumor-like mass which was clinically mistaken for a lymphatic malformation. PRIMARY LINGUAL TUBERCULOSIS, A RARE CASE REPORT PIERWOTNA GRUŹLICA JĘZYKA, RZADKI OPIS PRZYPADKU

Evaluation of neck swelling by cytological and histopathological examination

Objective: In this study 50 patients of neck swelling were studied to compare the findings with clinical diagnosis and histopathological report for its diagnostic reliability.Methods: This cross sectional study was done in ENT Department of Sher-E-Bangla Medical College Hospital, Barisal, Bangabandhu Sheikh Mujib Medical University and Dhaka Medical College Hospital, Dhaka from July 2006 to December 2006. Fine needle aspiration cytology, MRI, CT scan, and histopathological examination of postoperative specimen of neck swelling, analyzed data presented by various tables, graphs and figures.Results: In the present series 50 cases of neck swelling were studied. Out of these 50 cases 19 were male and 31 were female. The male, female ratio was 1:1.63. Age range was 4 – 60 years with maximum frequency in the 4th decade with the 3rd and 2nd in the following suit. Most of the patient was poor. Clinical, cytological and histopathological diagnosis was available in all the cases. The three sorts of diagnoses were compared with each other. Histopathologically 12 cases were tubercular lymphadenopathy, 12 cases were nodular goiter, 5 cases were Metastatic carcinoma, 5 were thyroid carcinoma and another 5 cases were lymphoma, Rest were benign, congenital and nonspecific inflammatory conditions. Correct diagnosis was made by FNAC in 45 cases. In the rest 5 cases smear were unsatisfactory in 2 cases and gives inconclusive result, remaining 3 were follicular neoplasmand no definitive result were made which were subsequently diagnosed by histopathological examination as a follicular adenoma in 1 and follicular carcinoma in 2. Sensitivity of FNAC in the diagnosis of neck masses were found 91% for tuberculosis, 100% for metastatic carcinoma and also for salivary gland tumour. In case of nodular goiter sensitivity was 92%. But it is only 60% sensitive in case of thyroid malignancy, as FNAC can not demarcate clearly between follicular adenoma and follicular cell carcinoma. But its accuracy in diagnosing papillary carcinoma of thyroid was 100%.Conclusion: FNAC can reduce substantially the need of open biopsy for histopathological examination. Accuracy of FNAC will be improved with relevant information provided by clinicians.DOI: http://dx.doi.org/10.3329/bjo.v18i1.10410 Bangladesh J Otorhinolaryngol 2012; 18(1): 23-29

A SWOLLEN MIDDLE FINGER IN A MIDDLE-AGED FARMER

Hand tumors are not common and a swollen finger poses considerable diagnostic dilemma. We present a case of a middle-aged farmer who had presented with a painless swelling of the middle finger of the right hand without any neurovascular deficit or evidence of metastasis. An X-ray of the finger showed cortical expansion and bony erosion of the proximal phalanx. A fine needle aspiration cytological examination was inconclusive. He underwent a digit amputation in view of subsequent morbidity and chances of recurrence following local excision. Biopsy proved it to be a giant cell tumor of the proximal phalanx. Following six months of treatment he is doing well. We herein highlight an unusual tumor of the finger and its diagnostic and treatment challenges.

Metastatic balloon cell melanoma-a rare differential in the diagnosis of clear cell tumors: Report of two cases

Two patients aged 65 and 66 years old presented with an enlarged inguinal lymph node. Clinically and radiographically, the inguinal mass was considered to be metastatic; however, first patient had no history of primary neoplasm. A fine-needle aspiration (FNA) cytologic examination of inguinal lymph node in both the cases showed numerous discohesive, pleomophic tumor cells with abundant, vacuolated cytoplasm and eccentrically placed round to ovoid nucleus with inconspicuous nucleoli and frequent intranuclear cytoplasmic pseudoinclusions. Pigment was not identified in the FNA of both the cases. Histopathological examination of the inguinal lymph node biopsy confirmed the diagnosis. These features, along with strong immunohistochemical positivity for HMB-45, suggested the diagnosis of metastatic balloon cell melanoma.

Monoclonal immunoglobulin protein production in two dogs with secretory B-cell lymphoma with Mott cell differentiation

A 9-year-old castrated male mixed-breed dog and a 7-year-old spayed female Boston Terrier, with clinical histories of a liver mass (dog 1) and bloody vomitus, diarrhea, and weight loss (dog 2), respectively, were referred for further evaluation. At the time of referral, each dog had differing laboratory abnormalities; however, the serum total protein and globulin concentrations were within reference range in both dogs. Cytologic examination of fine-needle aspirates obtained from affected organs (a liver mass [dog 1] and enlarged submandibular lymph node [dog 2]) revealed 2 main nucleated cell types: atypical lymphoid cells and lesser numbers of Mott cells. With the use of serum immunofixation electrophoresis and serum immunoglobulin quantification, a monoclonal immunoglobulin protein was identified in both dogs and a final diagnosis of secretory B-cell lymphoma with Mott cell differentiation (MCL) was made. Both dogs received chemotherapy for their disease. The first dog was euthanized 8.5 months after diagnosis because of acute respiratory distress of unknown etiology, and the second was euthanized 7 days after diagnosis for worsening clinical disease and quality of life. To our knowledge, this report is the first of a secretory form of MCL in dogs. Findings indicate that in dogs with suspect MCL, even in patients that lack characteristic hyperproteinemia or hyperglobulinemia, serum protein content should be fully evaluated for the presence of a monoclonal immunoglobulin protein. Such an evaluation that uses immunofixation electrophoresis and immunoglobulin quantification will aid in the diagnosis of MCL in dogs.

Differentiating Malignant From Benign Thickening of the Gallbladder Wall by the Use of Acoustic Radiation Force Impulse Elastography

The purpose of this study was to determine whether real-time elastography can differentiate gallbladder carcinoma from benign gallbladder wall thickening. Sonographic and real-time elastographic examinations were done in 125 of 2000 consecutive patients who had an increased gallbladder wall thickness of more than 3 mm. Shear wave velocities were determined for a normal gallbladder wall, a benign thickened gallbladder wall, and gallbladder carcinoma, and a value of 2.7 m/s was set as the cutoff to differentiate between benign and malignant wall thickening. Virtual touch and color maps of the gallbladder wall were also obtained. The final diagnosis was confirmed by histopathologic examination of the resected gallbladder or by guided fine-needle aspiration cytologic examination. Statistical analysis was done to determine the sensitivity and specificity of elastography for gallbladder carcinoma and benign wall thickening. Student t test and area under the receiver operating characteristic curve analyses were done to determine the statistical significance of the results. Elastography had sensitivity and specificity of 100% and 91.3%, respectively, for diagnosing gallbladder carcinoma with a mean shear wave velocity of 3.41 m/s (P < .0001) and an area under the curve of 0.92. False-positive findings of acute cholecystitis occurred in 8.5% of cases, which also had an increased shear wave velocity of greater than 2.7 m/s. The overall accuracy of elastography for differentiating gallbladder carcinoma from benign wall thickening was 92.8%. Elastography is an accurate technique for differentiating between benign and malignant gallbladder wall thickening and can be combined with sonography as the prime imaging tool for diagnosing gallbladder carcinoma at an early stage.

Ultrasonographic appearance of lymphomatous infiltration of the abomasum in cows with lymphoma

4 adult Holstein dairy cows were examined for anorexia and decreased milk production. Clinical signs included abdominal distension, normal to decreased ruminal motility, and decreased fecal output. Hypochloremia and high BUN concentration were also noted on serum biochemical analysis. Transabdominal ultrasonography revealed abnormal thickening of the abomasum with pyloric thickening and loss of the typical layered appearance of the pyloric wall. Results of cytologic examination of fine-needle aspirates of the abnormal portion of the abomasum were compatible with a diagnosis of lymphoma in 3 cows. The diagnosis of lymphoma involving the abomasum was confirmed by exploratory laparotomy, necropsy, or slaughterhouse reports. Two cows were euthanatized, 1 died 5 days after the diagnosis, and 1 was sent to the slaughterhouse, but the carcass was discarded because of generalized lymphoma. Transabdominal ultrasonography is a noninvasive portable test that can be useful for the diagnosis of lymphomatous infiltration of the pyloric portion of the abomasum, which may result in obstruction. This can be especially useful to avoid unnecessary treatments when no typical signs of enzootic lymphoma are present. Percutaneous fine-needle aspiration of the abnormally thickened abomasal wall should be performed. These procedures can enable diagnosis of this neoplasm, which has a relatively poor prognosis, thus avoiding the unnecessary costs incurred by exploratory laparotomy.

Is ultrasound alone sufficient for imaging superficial lobe benign parotid tumours before surgery?

Ultrasound (US) is a valuable technique for the assessment of salivary gland disease and regional nodes. When used in combination with fine needle aspiration cytology (FNAC) or core biopsy it has a high sensitivity and specificity in the diagnosis of tumours. The role of additional cross-sectional imaging (computed tomography (CT) or magnetic resonance (MR)) to help with the diagnosis of benign parotid tumours is questionable except when there is deep lobe extension or the suggestion of malignancy. We investigated 37 FNAC-confirmed benign parotid tumours in patients who had undergone both US and CT or MRI investigations, to find out whether cross-sectional imaging had provided any further useful diagnostic information before operation. Three patients had bilateral Warthin tumours. Tumours ranged in size from 11 to 45mm (mean 22). Of the 37 patients 35 (95%) had a clearly delineated mass in the superficial lobe of the parotid on US and no further information was gained from additional CT or MRI. On US 34 patients (92%) had features suggestive of a benign tumour, and three had features suggestive of malignancy but these were found to be benign on FNAC and after operation. CT or MRI confirmed these suspicious findings. In two different patients the deep margin was not visible on US (suggestive of deep lobe extension) and this was confirmed on MRI. The mean time delay between US and CT or MRI was four weeks (range 1–44). These results suggest that additional imaging is not required in most patients with a sonographically and FNAC confirmed benign lesion confined to the superficial lobe of the parotid and confirmed by FNAC or biopsy examination.

Paraneoplastic leukocytosis in a dog with a renal carcinoma

A 7-year-old male German Shepherd dog in poor body condition had a 3-month history of intermittent hematuria. Nonregenerative anemia, mild leukocytosis, marked hypoalbuminemia, and hematuria were observed. Subsequently, marked neutrophilia and moderate monocytosis were noted; anemia, hypoalbuminemia, and hematuria persisted; and the dog developed disseminated intravascular coagulation. Ultrasonographic examination of the abdomen revealed the presence of an enlarged and irregularly shaped right kidney with a large area of cavitation, and a nephrectomy was performed 30 days after initial examination. Cytologic examination of fine-needle aspirates and imprints of the right kidney revealed a neoplastic cell population suggestive of renal carcinoma. The histopathologic diagnosis was chromophobic cystic-papillary renal carcinoma. The tumor cells expressed granulocytic/macrophage-colony-stimulating factor (GM-CSF), detected by immunohistochemical staining, and elaboration of GM-CSF by the tumor may have mediated the leukocytosis in this dog. Following excision of the tumor, neutrophil and monocyte counts were only mildly increased. The dog died 135 days after initial presentation, and a necropsy was not permitted. Paraneoplastic neutrophilic leukocytosis is an uncommon finding and may be caused by elaboration of CSF by neoplastic cells.

Assessment of lymphatic drainage patterns and implications for the extent of neck dissection in head and neck melanoma patients

The aim of this study is to evaluate lymphatic drainage with sentinel node location data in patients with head and neck cutaneous melanoma, and to determine the implications for the extent of therapeutic neck dissections. Sixty-five patients with head and neck cutaneous melanoma without evidence of regional metastases at ultrasound guided fine needle aspiration cytology examination were included. Lymphatic drainage patterns were investigated using planar and dynamic lymphoscintigraphy, and SPECT/CT. Biopsy of sentinel nodes was guided by images and gamma probe. The incidence of discordant sentinel nodes was determined by comparing actual drainage patterns to "O'Briens map" and to the treatment guidelines of The Netherlands Cancer Institute. Sentinel node identification was successful in 98% of the patients. Fifteen patients (23%) were diagnosed with a tumor-positive sentinel node. Two sentinel node-negative patients (3%) developed a regional lymph node metastasis (false-negative ratio: 12%). Twenty-three percent of the harvested sentinel nodes were discordant according to "O'Brien's map," while 14% were discordant according to the treatment guidelines of The Netherlands Cancer Institute (P < 0.001). Almost a quarter of head and neck melanomas metastasize outside clinically predicted neck levels. Neck surgery guidelines of The Netherlands Cancer Institute provide for a smaller number of discordant sentinel nodes.

Manifestations of tuberculosis in HIV/AIDS patients and its relationship with CD4 count

Background:HIV/AIDS pandemic is responsible for the resurgence of TB worldwide, resulting in increased morbidity and mortality. HIV and Mycobacterium tuberculosis have a synergistic interaction; each propagates progression of the other. Coinfection with HIV infection leads to difficulties in both the diagnosis and treatment of tuberculosis, increase risk of death, treatment failure and relapse.Objective:The aim of the present study is to study the clinical, radiological profile of pulmonary and extrapulmonary tuberculosis (EPTB) in HIV-seropositive patients and their relationship to CD4 counts.Materials and Methods:It was a prospective study conducted over a period of 1 year in the department of medicine, Indira Gandhi Medical College, Shimla. We examined 87 HIV-infected patients with associated tuberculosis recruited from the department of medicine and antiretroviral center and were subjected to thorough clinical examination, X-ray chest, tuberculin testing and sputum examination for AFB and necessary relevant investigations for EPTB.Results:Most common affected age group was 31-40 years. EPTB is the commonest form of TB in our study detected in 65 patients. Commonest EPTB was CNS tuberculosis. Disseminated tuberculosis was only found in patient with CD4 count less than 200/cmm. Majority of lymph node TB was diagnosed by fine needle aspiration cytology (FNAC) examination. All patients with AFB-positive lymph node had CD4 count below 200/cum.Conclusions:The results of this study provide information regarding the various forms of TB and their presentation in HIV-infected persons. Early diagnosis of tuberculosis and prompt institution of antitubercular treatment (ATT) reduces mortality and morbidity significantly. In resource-poor areas, the diagnosis can be established with cytological/biochemical analysis of fluid, histopathological examination and ZN staining of tissue coupled with radiological features and response to ATT. Therefore, adequate knowledge of the manifestations of tuberculosis in HIV-infected patients is absolutely necessary for optimal management and to reduce mortality and morbidity.

Thymoma with Coexisting Undifferentiated Pleomorphic Sarcoma: A Case Report

We report here a case of thymoma simultaneously associated with undifferentiated pleomorphic sarcoma. A 45-year-old male presented with axillary lump. Radiographic studies showed a mediastinal mass. On fine needle aspiration cytology and histopathological examination, a diagnosis of thymoma with coexisting undifferentiated pleomorphic sarcoma was made. Although thymomas are associated with many extrathymic malignancies, it's association with undifferentiated pleomorphic sarcoma is rare. This case is being reported on to reinforce that clinicians should bear in mind the possibility of extrathymic malignancies in patients with thymomas.

Comparative Study between Breast Cytology and Histology in Saudi Females

The objective of this study is to outline the pattern of breast lesions in Saudi Arabian females who are diagnosed by Fine Needle Aspiration Cytology for a clinically palpable breast mass, and to determine the level of diagnostic accuracy in cytology with subsequent histological comparison whenever possible. A retrospective clinical study targeting 312 Saudi female patients being evaluated for clinically palpable breast mass that were performed and reported at King Abdulaziz University Hospital, Jeddah from 2000 to 2009. This result indicated that while fibroadenoma is the most frequent benign tumor, infiltrating duct carcinoma is the most common malignant tumor in Saudi Arabian females on Fine Needle Aspiration Cytology and histological examination. Based on this, the overall distribution of breast diseases was as follows: inflammatory lesions were 8.65%, benign lesions were 45.83%, highly suspicious/atypical lesions were 8.33%, malignant lesions were 30.76% and unsatisfactory smears were 6.41%. Analysis of histological correlation in patients revealed a sensitivity of 91.58% and a specificity of 97.75%. False negative fraction was of 4.59% which on histology turned out to be infiltrating duct carcinomas. Causes of cytohistological discrepancy were outlined in order to increase awareness of such conditions.

A Case of Cervical Actinomycosis Misdiagnosed to Malignant Tumor

Actinomyces are gram positive anaerobes which exist as normal flora in the oral and diges tive tract. Actinomycosis is a very rare subacute or chronic infectious disease that causes sinus fistula, tract or abscess due to the invasion of surrounding soft tissue when normal mu cosa is damaged by inflammation. Clinically, it is categorized into cervicofacial, thorax, abdomen, pelvis, and systemic infection, in which cervicofacial infection accounts for 50% of all actinomycosis. With various nonspecific clinical manifestations and uncertain results of fine needle aspiration cytology and culture examination, treatment may be difficult since it may be misdiagnosed as malignancy or tuberculosis. Along with literature, we present a case of a 57-year old male patient with cervical actinomycosis in the submandibular mass, which was mistaken for malignancy. � Korean J Otorhinolaryngol-Head Neck Surg 2011;54:427-30 Key WordsZZCervicofacial actinomycosis ㆍMalignant neoplasms.

Primary leiomyosarcoma of the breast treated by partial resection of the breast including nipple and areola: Report of a case

A 46-year-old female patient presented with a tumor measuring 0.5 cm in diameter under the areola of the breast. Because no definite malignancy was found with inspection and palpation, imaging analysis, or with a fine-needle aspiration cytology examination, follow-up observation was recommended. When the patient visited the hospital 6 months later, the mass was 0.9 cm in diameter. The tumor was excised and histopathologically diagnosed as a leiomyosarcoma. Subsequently, the patient underwent a partial resection of the breast, including the nipple and areola. A follow-up examination revealed no evidence of distant metastasis or local recurrences 8 years 4 months after the surgery. Primary leiomyosarcoma of the breast is extremely rare. Only 33 cases, which are reviewed in the present study, have been previously reported in the literature.

Pancreatic cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up

Pancreatic cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up S. Cascinu, M. Falconi, V. Valentini & S. Jelic On behalf of the ESMO Guidelines Working Group* Department of Medical Oncology, Universita Politecnica delle Marche, Ancona; Department of Surgery and Gastroenterology, University of Verona, Verona; Department of Radiotherapy, Universita Cattolica del Sacro Cuore, Rome, Italy; Internal Medicine Service, Institute of Oncology and Radiology, Belgrade, Serbia

Microfilaria in cytology smears from upper arm swelling

Sir, Filariasis is endemic in tropical countries such as India, China, Indonesia, parts of Asia and Africa.[1] The adult filarial worms reside in the lymphatic system from where the gravid female releases large number of microfilaria which may pass through the thoracic duct and pulmonary capillaries into the peripheral blood, and occasionally, microfilaraemia may be found in the infected patient. Microfilaria have been reported in variable locations like epididymis,[2] thyroid,[3] breast[4] and in variable specimens like bronchial washings, urine[5] and ovarian fluids.[6] Many of the cases reported have been incidental findings on fine needle aspiration cytology (FNAC) examination. Microfilaria of Wuchereria bancrofti are identified morphologically by the presence of hyaline sheath, length of cephalic space and presence of nuclei from head to tail, with tip free from the nuclei. It is common to find microfilaria in axillary lymph nodes;[7] however, to find them in a cystic swelling in the upper arm is very rare. We present an interesting case of an 18-year-old boy who presented with a cystic swelling on the medial aspect of the upper arm of 1 week duration, and was referred to the pathology department for FNAC. The swelling measured 2.5 × 1.0 cm and FNAC yielded straw colored fluid, Giemsa stained smears prepared from which showed numerous microfilaria of Wuchereria bancrofti in a clear background [Figure 1]. On further investigation, eosinophilia and microfilaraemia were found in the peripheral blood film. Prompt therapy was started which led to the resolution of the infection. Figure 1 FNAC smear shows microfilaria of Wuchereria bancrofti (tail tip free of nuclei) in a clear background (Giemsa, ×400) In conclusion, we emphasize the importance to consider filariasis in differential diagnosis in unusual cystic swellings, especially in endemic countries.

Diffusion‐weighted images differentiate benign from malignant thyroid nodules

To reveal the possible role of diffusion-weighted images (DWI) in the differential diagnosis of benign and malignant thyroid nodules by comparing the results of fine-needle aspiration cytology (FNAC). In an 18-month period (December 2005 to May 2007), 27 cases with benign thyroid nodules with a total of 52 benign nodules, nine cases with thyroid gland malignancy, and 24 healthy control cases were included in the study. Cases that were indicated to undergo to FNAC examination and sent by a clinician for biopsy to the radiology unit were included in the study to assess the cytopathologic confirmation of the clinic, ultrasonographic, and magnetic resonance imaging (MRI) findings. The mean apparent diffusion coefficient (ADC) values of thyroid nodules were 2745.3 +/- 601.1 x 10(-6) mm(2)/s (1605-3899 x 10(-6)mm(2)/s) in the benign group and 695.2 +/- 312.5 x 10(-6)mm(2)/s (165-1330 x 10(-6)mm(2)/s) in the malignant group. Normal thyroid tissues had mean ADC values of 1344.1 +/- 276.4 x 10(-6) mm(2)/s (1015-1764 x 10(-6)mm(2)/s). The ADC values of three subgroups were significantly different (P = 0.0001). A reduced ADC was observed in most types of malignant tumors due to the consequent decrease of the extracellular extravascular space. Our preliminary results showed that ADC values of nodules may provide useful data about the nature of a thyroid nodule.