Fine needle aspiration of metastatic and hematologic malignancies clinically mimicking pancreatic carcinoma.

The fine needle aspiration (FNA) cytology findings in 19 cases of hematopoietic and metastatic neoplasms that radiographically mimicked primary pancreatic carcinoma are reported. These cases represented 11% of 176 malignant diagnoses in a series of 304 pancreatic FNAs. The cytologic diagnoses included 7 non-Hodgkin's lymphomas, 2 Hodgkin's lymphomas, 6 small cell carcinomas (4 lung, 1 gallbladder, 1 skin), 3 squamous cell carcinomas (2 cervix, 1 esophagus) and 1 hepatocellular carcinoma. In six cases the pancreatic lesion was the initial presentation of malignant disease. These included five lymphomas, which probably involved peripancreatic lymph nodes, and a metastatic small cell carcinoma of pulmonary origin. Recognition of unusual morphologic features of pancreatic carcinoma raised the possibility of extrapancreatic malignancies. Electron microscopy and immunocytochemistry performed on FNA specimens were helpful in selected cases. The FNA diagnosis of hematopoietic and metastatic neoplasms that clinically mimic pancreatic carcinoma prompts appropriate clinical studies and treatment and eliminates the need for open pancreatic biopsy and/or resection.     

Metastatic tumors in fine needle aspiration biopsy of the thyroid

A series of almost 25,000 thyroids examined by fine needle aspiration (FNA) biopsy was reviewed to ascertain the incidence and presentation of metastatic cancers in thyroid FNA samples. Metastatic cancers in FNA samples from the thyroid were identified in 25 cases (0.1%); the primary tumors were carcinomas of the kidney (8 cases), lung (7 cases), breast (5 cases), cervix uteri (1 case) and colon (1 case) and 1 case each of malignant melanoma, malignant pleural mesothelioma and rhabdomyosarcoma. FNA cytology was positive in all 25 cases. In 11 cases, the primary tumor was clinically known at the time of FNA biopsy; of the other 14 cases, cytology suggested that the malignancy was metastatic in only 5. Metastases of renal and mammary adenocarcinomas were almost indistinguishable from follicular and papillary thyroid carcinomas on cytologic grounds. The results demonstrate the rarity of this finding and the difficulty of diagnosing a metastatic tumor in the thyroid by FNA biopsy, in the absence of a clinical history of a prior primary neoplasm.     

Cytologic diagnosis of reactive lymphadenopathy in fine needle aspiration biopsy specimens

Reactive or benign lymphadenopathies were cytologically diagnosed in the aspirates of 62 (23.5%) of 265 cases with enlarged lymph nodes of the head, neck or inguinal region subjected to fine needle aspiration (FNA) biopsy. The cytomorphologic features characteristic of reactive lymphadenopathy are described in detail; some of the cell patterns were suggestive of a specific disease process. The similarities of cells and cell patterns that may pose differential diagnostic problems with malignant lymphomas are pointed out. This study emphasizes the role of FNA cytology in the diagnosis of some benign conditions.     

Lymph node examination by fine needle aspiration in patients with known or suspected malignancy

In a series of more than 2,500 fine needle aspirates from multiple body sites, over 200 were clinically identified as lymph nodes from patients with known or suspected malignancy. The material was obtained using the easily manipulated Aspir-Gun with a 21-gauge or 22-gauge needle and syringe. Of the 200 lymph node specimens, 100 (50%) were cytologically reported as positive for malignancy. Ninety cases had surgical pathology specimens available for comparison with the fine needle aspiration (FNA) specimens. For the 88 of these cases with satisfactory FNA specimens, evaluation of the FNA results showed a predictive value of a positive result of 96.8%. These results compare favorably with those of surgical biopsy. The malignancies present in the lymph nodes included numerous adenocarcinomas from the breast, melanoma and pulmonary small-cell carcinoma. Six cases are briefly presented in which the FNA diagnosis was more problematic. While histologic examination of tissues or organs remains the desirable benchmark of comparison, the appropriate utilization of FNA cytology to guide therapy, particularly in a patient with previously diagnosed malignancy, may obviate the need for an open biopsy. The technique is convenient for patient and physician, useful for outpatients, relatively painless and provides good correlation between cytologic morphology and histopathology.     

Cytology of clear cell carcinoma of the female genital tract in fine needle aspirates and ascites

OBJECTIVE: To define the cytomorphologic features of clear cell carcinoma (CCC) of the female genital tract. STUDY DESIGN: The study consisted of four CCCs of the female genital tract in which clinical and histologic confirmation had been done. Cytologic findings were evaluated with May-Grünwald-Giemsa (MGG) stain of three cases of fine needle aspiration (FNA) material and peritoneal fluid cytology. All the FNA materials were obtained from metastatic supraclavicular lymph nodes. RESULTS: We report here the cytomorphologic features of three FNA biopsies and peritoneal fluid cytology from four patients. Primary tumors from patients with aspiration material from supraclavicular lymph nodes were located in the ovary in two patients and vagina in one. The peritoneal fluid cytology was obtained from a patient with uterine cervical tumor. Cytologic findings were similar in all preparations. The cells had abundant, pale, finely vacuolated cytoplasm with indistinct cytoplasmic membranes. The nuclei were round to oval, with fine chromatin. The characteristic feature of CCC of the genital tract was basement membrane-like substance. This hyaline extracellular material stained pinkish to purple-red in MGG preparations and was frequently observed within the cancer cell clusters. In ascitic fluid, psammoma bodies were also observed. CONCLUSION: The cytomorphologic characteristics of CCC of the genital tract are distinctive, and the entity may easily be diagnosed even at metastatic locations.     

Diagnostic value of fine needle aspirates processed by ThinPrep® for the assessment of axillary lymph node status in patients with invasive carcinoma of the breast

X. Jing, E. Wey and C. W. Michael Diagnostic value of fine needle aspirates processed by ThinPrep® for the assessment of axillary lymph node status in patients with invasive carcinoma of the breast Objective: To evaluate the utility of ThinPrep® as an optional specimen processing method for the detection of axillary lymph node metastasis of invasive breast carcinoma. Methods: A computer SNOMED search from the file at our institution between January 2003 and August 2011 retrieved a total of 209 fine needle aspiration (FNA) specimens of axillary lymph nodes prepared by ThinPrep and followed by axillary lymph node biopsy and/or dissection. Original cytological diagnoses and corresponding histological diagnoses were documented. Using the histological diagnoses as the gold standard, the diagnostic parameters including sensitivity, specificity, positive (PPV) and negative predictive values (NPV) and diagnostic accuracy were calculated. Both cytology and histology slides from cyto‐histologically discrepant cases were reviewed. Results: Out of a total of 209 specimens, 193 (92%) had adequate diagnostic material while the remaining 16 specimens (8%) were inadequate for cytological assessment. The diagnostic specimens included 168 invasive ductal carcinomas (IDC), 15 invasive lobular carcinomas (ILC) and 10 mixed carcinomas (IDC and ILC). Excluding 19 cases with malignant cells on FNA in which no residual tumour was found in fibrotic lymph nodes after neoadjuvant therapy (cytology and histology confirmed on review) ThinPrep detected nodal metastasis with an overall sensitivity of 77.5%, specificity of 100%, PPV of 100% and NPV of 53.7%. Diagnostic accuracy was 82.2%. There was no difference in Bloom–Richardson grade or the number or size of metastases between tumours with true‐positive and false‐negative cytology. Sampling error was the sole factor contributing to cyto‐histological discrepancy. Conclusions: ThinPrep is a good alternative to the conventional smear for cytological assessment of axillary lymph node status in patients with invasive breast carcinoma, particularly when specimens are collected at remote sites or when cytologists are not available for assistance during FNA.     

Cytomorphologic features of sebaceous carcinoma on fine needle aspiration

OBJECTIVE: To describe three cases of sebaceous carcinoma metastatic to regional lymph nodes diagnosed by fine needle aspiration (FNA). STUDY DESIGN: FNA was performed using standard techniques. A portion of each specimen was stained with Diff-Quick (Dade, Miami, Florida, U.S.A.); another portion was fixed in 95% ethanol and stained with a modified Papanicolaou stain or fixed in formalin and stained with hematoxylin and eosin. RESULTS: All carcinomas were moderately cellular, with primarily irregular cell clusters. The cytoplasm was finely reticular and contained variable numbers of small vaculoes. Nuclei were centrally located and pleomorphic and contained coarse chromatin. Variably sized but often large nucleoli were seen. Mitotic figures were easily identified. CONCLUSION: Sebaceous carcinoma is a rare but cytologically distinct neoplasm. It frequently metastasizes to regional lymph nodes and may then appear as a mass amenable to FNA. Aspiration cytologists, particularly those who aspirate head and neck lesions, should be familiar with the distinct features of this neoplasm.     

Value of the cytologic analysis of fine needle aspiration biopsy specimens in the diagnosis of pancreatic carcinomas

Between 1982 and 1986, 410 preoperative percutaneous fine needle aspiration (FNA) biopsies of the pancreas were performed on 316 patients clinically suspected of having a malignant pancreatic tumor. Of 58 patients with pancreatic carcinomas subsequently confirmed by histologic investigation, the FNA biopsy yielded a cytologically positive diagnosis of carcinoma in 39 cases (67.2%) and suspicious findings in another 5 cases (8.6%). In 14 cases of malignancy (24.1%), the FNA puncture failed to sample material from the tumor; hence, the cytologic evaluation yielded false-negative results. Of 21 patients with inflammatory disorders of the pancreas, cytologically suspicious cells were observed in 5 cases (23.8%); in none of those 5 cases did the histologic examination show any evidence of carcinoma. This indicates that caution should be taken not to cytologically over-diagnose cases of pancreatitis. On the whole, cytology proved to be a valuable method for the diagnosis of pancreatic carcinoma; it provided the highest rate of positive results in comparison with other modern clinical diagnostic methods. Furthermore, cytology may improve the diagnostic results even in those cases with clinically negative or merely suspicious findings. FNA punctures of the pancreas produced no serious complications in this series.     

Fine needle aspiration of follicular variant of papillary thyroid carcinoma presenting with pleural effusion: a case report

BACKGROUND: Malignant pleural effusion in association with mesothelioma, bronchogenic carcinoma and breast carcinoma is common, although less frequently reported with other malignancies. We report a follicular variant of papillary thyroid carcinoma (FVPTC), diagnosed on fine needle aspiration cytology (FNAC) of thyroid and lymph nodes and subsequently proved to have metastasized to the pleural cavity. CASE: A 46-year-old man presented with history of breathlessness, thyroid swelling, pleural effusion and bilateral cervical lymphadenopathy. FNAC of the thyroid swelling and the lymph nodes showed features of FVPTC with cervical lymph node metastasis. Pleural fluid examination led to suspicion of pleural involvement by metastatic deposit, confirmed by subsequent pleural biopsy. CONCLUSION: Thyroid malignancies presenting with pleural effusion are rare. In this case, although pleural fluid cytology suggested involvement of pleura, a definitive diagnosis could be rendered only on pleural biopsy. An ancillary aid, such as immunocytochemistry, could have helped establish pleural involvement on routine pleural fluid cytology alone. This case emphasizes the possible existence of rare cases of FVPTC that may be associated with a dismal prognosis. In our case, initial diagnosis of FVPTC could be made only on correlating FNA features of thyroid aspirate with those of lymph node aspirate.     

Value of Repeating A Nondiagnostic Thyroid Fine-Needle Aspiration Biopsy

ObjectiveTo assess the value of repeating a biopsy when the initial thyroid fine-needle aspiration (FNA) biopsy is nondiagnostic.MethodsBetween 1990 and 2003, 4,311 thyroid FNAs were performed at the Cleveland Clinic Foundation, of which 220 (5%) were nondiagnostic. Among 189 patients whose medical records were available for retrospective review, 106 underwent a repeated FNA (FNA #2), and 14 had a second repeated FNA (FNA #3). Thyroid ultrasonography was used in the evaluation in 113 FNAs.ResultsThe first and second repeated FNAs were diagnostic in 58% (62 of 106 patients) and 50% (7 of 14 patients), respectively. The rate of malignant disease in patients with no repeated FNAs versus 1 or more repeated FNAs was 4.8% (4 of 83) versus 11.3% (12 of 106), respectively. Ultrasound-guided FNA yielded a diagnosis among 33 of 113 biopsies (29.2%), and FNA without ultrasound guidance provided a diagnosis in 30 of 159 biopsies (18.9%). Thus, the use of thyroid ultrasonography significantly improved the likelihood of establishing a diagnosis (P = 0.017). We found that repeating the FNA up to 2 times provides a diagnosis in up to 60% of cases.ConclusionThe overall prevalence of thyroid cancer in patients with nondiagnostic FNA is not trivial—8.5% in our study group of 189 patients. An aggressive approach toward nondiagnostic FNA biopsies is recommended, with performance of at least 2 repeated FNA biopsies, preferably with the help of ultrasound guidance. (Endocr Pract. 2007;13:735-742)     

Posters. P19 Cervical carcinoma with metastases to the tympanic membrane: an unusual presentation

Introduction Fine needle aspiration (FNA) is a well‐established diagnostic technique which is frequently used to diagnose head and neck neoplasms. Clinical decisions concerning treatment of malignant salivary gland tumours, the extent of surgery and advisability of pre‐operative irradiation can be helped by prior knowledge of tumour type. Aim The aim of this study was to do an audit of all salivary gland FNAs carried out in Beaumont Hospital over a 14‐year period. Methods All salivary gland FNAs between 1989 and 2002 were reviewed. Where available, the corresponding follow‐up histological specimens were studied. Results During this 14‐year period, 305 patients with salivary gland lesions had FNA of the lesion performed. The total number of aspirates performed was 343. Of these, 184 had histologies available for follow‐up. Eighty‐nine aspirates were reported as inadequate; 89 as inflammatory, normal or consistent with cyst contents. One hundred and thirteen aspirates were diagnosed as a benign entity. Thirty‐three aspirates were reported as malignant (21 of which were felt to be primary to the salivary gland and 12 metastatic). Sixteen cases were called suspicious. Good correlation between FNA findings and histology was seen in the majority of cases (145 of 183). Some diagnostic problem areas were identified. These included the following: lymphomas (seven called benign on FNA), Warthin's tumour (seven not diagnosed or misdiagnosed on FNA) and mucoepidermoid carcinoma (one reported as pleomorhic adenoma and one as benign/cystic on FNA). Seven pleomorphic adenomas were not diagnosed on FNA pre‐operatively, predominantly due to inadequacy of the specimen. Three other malignancies (acinic cell carcinoma, lymphoepithelial carcinoma and carcinoma ex‐pleomorphic adenoma), while not diagnosed on FNA, were called suspicious, with re‐biopsy advised. Conclusion FNA cytology of salivary glands is an accurate method for evaluation of both benign and malignant lesions, enabling optimum surgical and adjuvant therapy decision‐making pre‐operatively. Well‐defined problem areas are identified and, therefore, clinicopathological correlation is required in these cases.     

Diagnostic value of lymph node fine needle aspiration cytology: an institutional experience of 387 cases observed over a 5-year period

Lymph node fine needle aspiration (LNFNA) cytology is valuable in solving the diagnostic problems of clinical adenopathy. The usefulness of the procedure in the staging and diagnosis of various malignant and lymphoproliferative tumours, as well as its role in distinguishing reactive hyperplastic lymph nodes from lymphoma, has been documented in the literature generally on an individual basis. We report our cumulative 5 year experience of LNFNA representing 387 cases. Approximately half (n = 182) were diagnosed as either metastatic carcinoma or melanoma; in 54 cases (30%) excisional biopsy or tissue study was performed to confirm the diagnosis; there was only one false-positive diagnosis of a metastatic squamous carcinoma rendered on a submandibular lymph node. Sixty-one lymphoma cases were successfully diagnosed via LNFNA with no false positives; concurrent flow cytometry was utilized in 51% (n = 31) of the 61 cases and supported the cytologic diagnosis of lymphoma in 27 of the 31 cases (87%). A benign or reactive lymph node process was also diagnosed via LNFNA alone or in combination with flow cytometry in 48 cases with only five false negatives, which included four cases of mantle cell lymphoma and one case of melanoma. Unsatisfactory cases accounted for 12%, and represented specimens obtained by 'Wang needle' or other emerging techniques. Our study demonstrates that LNFNA can be an accurate, economical and rapid diagnostic procedure.     

Fine needle aspiration cytodiagnosis of nasopharyngeal carcinoma in cervical lymph nodes. A study of 40 cases

The cytologic features of fine needle aspiration (FNA) samples of 40 metastatic nasopharyngeal carcinomas in cervical lymph nodes were reviewed. FNA was performed with 21-gauge or 23-gauge needles; the FNA smears were stained with the Papanicolaou stain or with hematoxylin and eosin. Several typical cytologic features were noted. All cases showed the presence of clusters of cohesive tumor cells, most of which were undifferentiated. Medium-sized oval vesicular nuclei were present in 85% of the cases; all cases had prominent nucleoli. The cytoplasm was generally pale, with ill-defined boundaries in 87.5% of the cases. Mitoses were present in 75% of the cases. Mature lymphocytes were intermingled with tumor cells in all cases. The cytologic features correlated with the histologic features in surgical biopsies of the nasopharynx and lymph nodes. The results show that FNA of cervical lymph nodes can aid in the diagnosis of otherwise occult nasopharyngeal carcinoma and in detecting residual or recurrent nodal disease in patients with nasopharyngeal carcinoma who had undergone treatment.     

Fine needle aspiration cytology of neuroblastoma, including peripheral neuroectodermal tumor, with immunocytochemical and ultrastructural confirmation

Eleven fine needle aspiration (FNA) biopsies were performed on seven children with neuroblastoma, including one patient with a congenital neuroblastoma and another with a peripheral neuroblastoma of the thoracopulmonary region. FNA cytology made the primary diagnosis of neuroblastoma in four of the seven cases. The other biopsies documented local recurrences and metastases to liver, lymph nodes, orbit and breast. The cytologic features included varying numbers of small primitive cells with scanty cytoplasm, poorly to well-formed pseudorosettes, cell processes, a fibrillary matrix and multinucleated ganglion cells. Five of the seven patients had electron microscopic (EM) examination of the FNA specimen, which in all cases confirmed the diagnosis. Batteries of immunoperoxidase stains were performed on all 11 aspirates with variable results. Staining for neuron-specific enolase was positive in four of the five neoplasms tested, although strongly positive in only three of the cases. Staining for neurofilament markers was positive in only two of five tumors. Studies for cytokeratin markers (AE1/3), low-molecular-weight cytokeratin (35BH11), hematopoietic markers (T29/33), immunoglobulin light chains and myoglobin were negative. One case was positive for vimentin. This study attests to the value of FNA cytology in suggesting a correct diagnosis of either primary, recurrent or metastatic neuroblastoma in children. Selective use of immunoperoxidase stains and EM on the aspirates may be of value.     

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA): experience of an academic centre in the USA

S. Zhang, D. V. S. DeFrias, R. Alasadi and R. Nayar
Endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA): experience of an academic centre in the USA Objectives: Endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) has become widely accepted as an effective modality for obtaining tissue for primary diagnosis and staging. We have been using EUS‐FNA since July 2001 and herein we summarize our experience over a 5‐year period. Methods: A computer‐based search for in‐house EUS‐FNA was performed in the pathology database from July 2001 to October 2006. To calculate the sensitivity, specificity and accuracy of EUS‐FNA, the cytology diagnosis was compared with the surgical follow‐up. Results: A total of 951 EUS‐FNAs were performed during the study period and included 279 pancreatic solid lesions, 186 pancreatic cyst lesions, 249 lymph node aspirations, 111 gastrointestinal (GI) tract submucosal lesions, and 126 miscellaneous lesions. EUS‐FNA had a very high sensitivity and accuracy for solid pancreatic lesions (94.7 and 97.7%, respectively), low sensitivity and accuracy but high specificity (47, 64.8 and 95%, respectively) for cystic lesions. Cyst fluid carcinoembryonic (CEA) levels were significantly higher in mucinous neoplasms than non‐neoplastic cysts. EUS‐FNA also had very high sensitivity and specificity for detecting metastatic carcinoma in lymph nodes (95 and 100%, respectively). GI submucosal spindle cell tumours were further classified with immunohistochemical stains performed either on a cell block or a core biopsy obtained via EUS guidance. Conclusions: EUS‐FNA has a very high sensitivity and accuracy for pancreatic solid lesions, but the sensitivity for cystic lesions is generally low. Cyst fluid chemical analysis for CEA is helpful, but the overlap between mucinous neoplasm and non‐neoplastic cysts is significant. Recognizing GI contamination is important and immunohistochemical stains are useful for GI submucosal spindle cell lesions.     

Cytology of metastatic neuroendocrine (Merkel-cell) carcinoma in pleural fluid. A case report

A case of Merkel-cell (neuroendocrine) carcinoma of the skin with extensive metastases, including pleural effusion, occurring over 20 years after primary resection and treatment, is reported. The histologic appearance of the primary neoplasm was identical to that seen in the biopsy specimens of the metastatic carcinoma involving the great toe and inguinal lymph nodes and to that of the residual neoplasm tissue found at necropsy. Electron microscopic examination of a lymph node metastasis demonstrated cytoplasmic microfilaments and numerous dense-core, peripheral, neurosecretory granules, as previously described in Merkel-cell carcinoma. Cytologic examination of a pleural fluid specimen demonstrated numerous small malignant cells closely resembling the cells seen in the histopathologic sections from the surgical and necropsy tissues involved by metastatic carcinoma. This is the first report of the cytologic findings in a patient with Merkel-cell carcinoma metastatic to the pleural cavity.     

Cytology of mesothelioma of the tunica vaginalis metastatic to the lung

The case of a 63-year-old man with malignant mesothelioma of the tunica vaginalis testis confirmed by electron microscopy is presented. The tumor recurred in the scrotal skin and subsequently metastasized to the inguinal and retroperitoneal lymph nodes. Four and a half years after the original diagnosis, pulmonary metastases were discovered by cytologic examination of bronchial washings and confirmed by transbronchial lung biopsy. The cytologic features of the metastatic malignant mesothelial cells are described and compared to those of mesothelioma cells in body cavity fluids. The role of cytology in the early detection of such tumors is discussed.     

Fine needle aspiration of breast masses. An analysis of 276 aspirates

A study of 276 consecutive fine needle aspirations (FNAs) of the breast in 240 cases is presented. Of these cases, 108 underwent subsequent biopsy of the breast; correlations between the FNA cytology and the surgical pathology findings revealed that FNA had a sensitivity of 79.4%, a specificity of 100% and a predictive value of a positive diagnosis of 100%. The overall diagnostic accuracy was 92.4%. These results are compared with those in other published series, and the pitfalls in and methods of improvement of breast FNA are discussed.     

Diagnostic utility of fine needle aspiration (FNA) cytology in HIV-infected patients with lymphadenopathy

reid a. j. c., miller r. f. and kocjan g. i. (1998) Cytopathology 9, 230–239
Diagnostic utility of fine needle aspiration (FNA) cytology in HIV-infected patients with lymphadenopathy
Sixty-five FNA cytology procedures were performed on lymph nodes in 52 HIV⁺ patients. Cervical lymph nodes were the commonest site of FNA cytology investigation (54%). The diagnoses were persistent generalized lymphadenopathy (38%), infection (17%), and malignancy (11%). Diagnosis could not be rendered in 25% of FNA cytology due to inadequate sampling. Of those with infection, mycobacterial disease was the commonest cause (91%), the diagnosis of which was enhanced by concurrent microbiological examination. Non-Hodgkin's lymphoma was the commonest malignancy. Sixteen lymph node FNA cytologies had subsequent tissue biopsy. There were two false-positive and four false-negative FNA cytologies. FNA cytology in HIV⁺ patients is most useful in the diagnosis of infection, obviating the need for tissue biopsy and allowing prompt initiation of treatment.     

Asymptomatic esophageal squamous cell carcinoma masquerading as a rare primary pancreatic carcinoma. Diagnosis by percutaneous fine needle aspiration

An unusual case of asymptomatic squamous cell carcinoma of the esophagus metastatic to the pancreas, mimicking a rare primary pancreatic neoplasm, is reported. Percutaneous fine needle aspiration (FNA) biopsy of a pancreatic lesion showed squamous cell carcinoma, which in the pancreas is virtually always metastatic in origin. This prompted a search for an occult primary elsewhere, resulting in the discovery of an esophageal neoplasm, which in itself is one of the least likely sources of pancreatic metastases. FNA biopsy was thus a useful and accurate diagnostic tool in establishing the true nature of the pancreatic neoplasm, sparing the patient unnecessary pancreatic surgery, with its attendant morbidity and hospital costs.