Giant-cell containing neoplasms of the pancreas: an aspiration cytology study

Anaplastic (undifferentiated) carcinoma of pancreas, an uncommon variant: Diagnosed on endoscopic-guided fine needle aspiration

Anaplastic carcinoma of pancreas (ACP) are rare pancreatic neoplasms. They are well known to be associated with more aggressive tumor behavior and less favorable prognosis than usual pancreatic ductal adenocarcinoma. Endoscopic-guided fine needle aspiration (EUS-FNA) is now a widely accepted modality in diagnosis of pancreatic lesions. However, only a few reports are available describing cytological features of anaplastic carcinoma. Here, we report two cases of ACP diagnosed on EUS-FNA.

EUS-guided fine needle biopsy is able to provide diagnosis in rare osteoclast-like giant cells undifferentiated carcinoma of the pancreas: Report of two cases

Undifferentiated carcinoma of the pancreas with osteoclast-like giant cells (UC-OGC) is a rare subtype of pancreatic cancer, accounting for less than 1% of all pancreatic tumors. Preoperative diagnosis is cumbersome as cross-sectional imaging is often not capable to distinguish between UCOGC and other pancreatic tumors such as pancreatic adenocarcinoma, mucinous carcinoma or neuroendocrine tumors and specific tumor markers seem to be lacking. Endoscopic ultrasound r `m(EUS) with tissue acquisition via fine-needle aspiration (FNA) or biopsy (FNB) with microscopic HE staining and immunohistochemistry allows for an accurate diagnosis, thus influencing further treatment. We present herein the cases of two patients with osteoclast-like giant cells tumors of the pancreas diagnosed by EUS-guided fine needle biopsy and perform a literature review on the role of EUS-guided biopsy for diagnosis.

Undifferentiated carcinoma with osteoclast-like giant cells of pancreas on cytology: A case report with review of literature

Undifferentiated carcinoma with osteoclast-like giant cells (UC-OGC) is a rare malignant neoplasm accounting for <1% of pancreatic masses. Very few case reports and small series have described the cytomorphological features of this entity. We report a case of UC-OGC arising in the pancreas presenting with liver metastasis in a 56-year-old man diagnosed by guided fine-needle aspiration cytology (FNAC). A characteristic biphasic pattern comprising of malignant mononuclear cells with scattered bland giant cells were the hallmark features for cytological diagnosis. Our case along with review of cytology literature emphasize the utility of FNAC and the cell block in the diagnosis and management of this rare entity.

Undifferentiated Carcinoma of Pancreas with Osteoclast-Like Giant Cells: One Center’s Experience of 13 Cases and Characteristic Pre-Operative Images

Background

Methods

Results

Conclusion

Cephalic undifferentiated carcinoma with osteoclast-like giant cells arising from the main pancreatic duct: case report and literature review

Undifferentiated carcinoma with osteoclast-like giant cell (UCOGC) is a ductal carcinoma variant with a recently reported more protracted survival and pathognomonic histology comprising two cell populations: the mononuclear tumoral cells and nontumoral multinucleated giant cells. It usually presents as a large heterogenic tumor with mixed solid-cystic components. The tumor develops from the ductal epithelium but the sequence of epithelial changes is often not identified due to the rapid tumoral growth and associated necrotic changes. We report a case of a 76-year-old patient diagnosed with cephalic UCOGC originating in the epithelium of the main pancreatic duct with endoluminal growth and foci of other ductal neoplasms (high-grade pancreatic intraepithelial neoplasia (PanIN) and conventional ductal carcinoma). The particularity of our case consists in the identification of the columnar epithelium conversion, through high-grade PanIN, into UCOGC specific malignant features, in a large size tumor - aspect usually reported in small tumors. Alongside our case we also present a brief literature review of cephalic UCOGC case reports and case series.

SMARCB1/INI1-deficient pancreatic undifferentiated rhabdoid carcinoma mimicking solid pseudopapillary neoplasm: A case report and review of the literature

BACKGROUND

SMARCB1/INI1-deficient pancreatic undifferentiated rhabdoid carcinoma is a very aggressive tumor that is rarely reported in the literature. The tumor has a predominant rhabdoid cell component and different patterns of growth have been reported.

CASE SUMMARY

A 59-year-old woman presented with diffuse abdominal pain, increasing in severity and accompanied by weight loss, nausea, and vomiting. Imaging showed a pancreatic head mass. Fine needle aspiration demonstrated atypical epithelioid cells with a pseudopapillary growth pattern suggestive of solid pseudopapillary neoplasm. The excised neoplasm showed monotonous epithelioid and focally spindle cells with pseudopapillary structures, rhabdoid features, and loss of SMARCB1 protein expression with wild-type KRAS, consistent with a SMARCB1/INI1-deficient undifferentiated rhabdoid carcinoma. The patient’s condition deteriorated rapidly following surgery and she expired 3 mo post operation.

CONCLUSION

In this article, we report the first case of SMARCB1/INI1-deficient undifferentiated pancreatic rhabdoid carcinoma mimicking solid pseudopapillary neoplasm.

A Case Report Presenting an Undifferentiated Pancreatic Carcinoma with Osteoclastic-Like Giant Cells with an Unusual Indolent Course

BACKGROUND Undifferentiated pancreatic carcinoma with osteoclast-like giant cells represents less than 1% of pancreatic cancers. Histogenesis and prognosis are still debated. Three subtypes are defined by the World Health Organization: osteoclastic, pleomorphic, and mixed. The differential diagnosis of a pancreatic tumor with giant cells varies from a benign osteoclastoma to an undifferentiated pancreatic carcinoma with osteoclastic-like cells. The specimen should be carefully examined to rule out conventional pancreatic adenocarcinoma even in the presence of the giant cells. CASE REPORT A 77-year-old male was diagnosed with a pancreatic tail tumor with osteoclastic like cells revealed by a biopsy done by echo-endoscopy; the patient was lost to follow up for 24 months before he was admitted to our institute for severe abdominal pain. A computed tomography showed the same lesion without progression. He was operated on using laparoscopic distal pancreatectomy with splenectomy. Pathology analysis revealed the presence of osteoclast-like giant cells without pleomorphic cells. Mutated KRAS on molecular study confirmed the diagnosis of undifferentiated pancreatic carcinoma with osteoclast-like giant cells. The patient was in good performance status and disease-free 19 months after surgery without any sign of progression. CONCLUSIONS Undifferentiated pancreatic carcinoma with osteoclast-like cells has a challenging pathology diagnosis. Molecular and immunostaining are essential to diagnosis. The absence of pleomorphic cells in the present case has classified it into the osteoclastic subtype. Further cases and studies are needed to confirm the heterogeneity of the malignant course between subtypes.

Cytopathology of anaplastic carcinoma of the pancreas: Review of a rare entity and description of a variant with signet ring cell features

Anaplastic carcinoma of the pancreas (ACP) is a rare and aggressive variant of pancreatic ductal adenocarcinoma (PDAC). Several studies have attempted to characterize this subtype through case series or single case reports; however, ACP remains underrecognized by cytopathologists in particular, and often lumped under the umbrella of classic PDAC. Here, we review the most up to date data that literature provides about ACP, to bring familiarity with this entity to the cytopathology practice, and to elucidate the role cytopathologists can play in recognizing and diagnosing this subtype on pancreatic aspiration biopsy, before surgical resection. We also describe a rare case of ACP, demonstrating signet ring cell features, that was diagnosed on fine needle aspiration of a pancreatic mass.

Sarcomatoid carcinoma of the pancreas: A case report

BACKGROUND

Sarcomatoid carcinoma of the pancreas (SCP) is a rare and aggressive epithelial tumor that has both epithelial and mesenchymal features. It is characterized by sarcomatous elements with evidence of epithelial differentiation. And the term “sarcomatoid carcinoma” is often confused with “carcinosarcoma”.

CASE SUMMARY

We present a case of SCP with lymph node metastasis in a 59-year-old male patient. He had experienced darkening of the urine, scleral icterus, and fatigue for 4 weeks. Computed tomography and magnetic resonance imaging revealed a mass in the pancreatic head, and laboratory tests revealed elevated serum bilirubin levels. The patient underwent pancreaticoduodenectomy after biliary decompression. Histologically, spindle cells with marked nuclear atypia and brisk mitotic activity arranged in a storiform or fascicular pattern were present in the bulk of the tumor. Immunohistochemical analysis found that the spindle cells exhibited strong diffuse positivity for epithelial markers, indicative of epithelial differentiation. Accordingly, the pathologic diagnosis of the pancreatic neoplasm was SCP.

CONCLUSION

Although sarcomatoid carcinomas and carcinosarcomas have different pathologic features, both have epithelial origin.

Anaplastic carcinoma of the pancreas diagnosed by endoscopic ultrasound-guided fine-needle aspiration: a case report and review of the literature

Background

Anaplastic carcinoma of the pancreas is a rare pancreatic neoplasm with a poor prognosis. It is classified as a variant of ductal adenocarcinoma, but the clinical features and treatment of it remain unknown because of its rarity and aggressiveness. Endoscopic ultrasonography and endoscopic ultrasound-guided fine-needle aspiration are useful techniques for the diagnosis of pancreatic tumors with high sensitivity and specificity.

Case presentation

A 72-year-old Japanese woman presented with a diagnosis of acute pancreatitis, and a cystic lesion with slightly high density area was observed by computed tomography in her pancreatic head. In addition, endoscopic ultrasound revealed a heterogeneous lesion. Endoscopic ultrasound-guided fine-needle aspiration showed pleomorphic atypical cells. We diagnosed anaplastic carcinoma of the pancreas. We resected the lesion, and she has shown no sign of recurrence for > 6 months. There are few reports of anaplastic carcinoma of the pancreas diagnosed by endoscopic ultrasound-guided fine-needle aspiration and treated by surgery. Our analysis indicates that anaplastic carcinoma of the pancreas is more likely than typical ductal carcinomas to have cystic lesions with the tumor.

Conclusions

We report a case of anaplastic carcinoma of the pancreas diagnosed by endoscopic ultrasound-guided fine-needle aspiration and subsequently resected with a clear margin. We speculate that anaplastic carcinoma of the pancreas is more likely to have cystic changes than pancreatic ductal adenocarcinoma. When we diagnose pancreas tumor as having cystic changes, anaplastic carcinoma of the pancreas should be considered one of the differential diagnoses.

Citología por punción-aspiración con aguja fina guiada por ultrasonido endoscópico en el diagnóstico de adenocarcinoma ductal de páncreas

El cáncer de páncreas es la cuarta causa de muerte por cáncer en los Estados Unidos; en el mundo se asocia con 227.000 muertes anuales, aproximadamente. Es producto de múltiples factores, siendo el tabaquismo el principal factor de riesgo.La punción-aspiración con aguja fina guiada por ultrasonido endoscópico es una técnica muy eficaz en el diagnóstico de lesiones neoplásicas del páncreas. El diagnóstico citológico mediante esta técnica debe hacerse según los lineamientos para el sistema pancreático-biliar de la Papanicolaou Society of Cytopathology. Dichos lineamientos incluyen las indicaciones, las técnicas, la terminología y la nomenclatura, así como los estudios auxiliares, el manejo posterior al procedimiento y los criterios citológicos para el diagnóstico.La especificidad de una interpretación positiva o maligna para la punción-aspiración pancreática con aguja fina, es de 90 a 95 % en la mayoría de los estudios.

Pancreatic undifferentiated rhabdoid carcinoma: KRAS alterations and SMARCB1 expression status define two subtypes

Pancreatic undifferentiated carcinoma is a heterogeneous group of neoplasms, including pleomorphic giant cell, sarcomatoid, round cell, and rhabdoid carcinomas, the molecular profiles of which have so far been insufficiently characterized. We studied 14 undifferentiated carcinomas with prominent rhabdoid cells, occurring as advanced tumors in seven females and seven males aged 44-96 years (mean: 65 years). Histologically, 10 tumors qualified as pleomorphic giant cell and 4 as monomorphic anaplastic carcinomas. A glandular component, either in the primary or in the metastases, was seen in 5 out of 14 tumors (4 out of 10 pleomorphic giant cell and 1 out of 4 monomorphic anaplastic subtypes, respectively). Osteoclast-like giant cells were absent. Immunohistochemistry revealed coexpression of cytokeratin and vimentin, and loss of membranous β-catenin and E-cadherin staining in the majority of cases. Nuclear SMARCB1 (INI1) expression was lost in 4 out of 14 cases (28%), representing all 4 tumors of the monomorphic anaplastic subtype. FISH and mutation testing of KRAS revealed KRAS amplification in 5 out of 13 (38%) and exon 2 mutations in 6 out of 11 (54%) successfully analyzed cases. A strong correlation was found between KRAS alterations (mutation and/or copy number changes) and intact SMARCB1 expression (7 out of 8; 87%). On the other hand, loss of SMARCB1 expression correlated with the absence of KRAS alterations (3 out of 5 cases; 60%). The results suggest that rhabdoid phenotype in pancreatic undifferentiated rhabdoid carcinomas has a heterogeneous genetic background. SMARCB1 loss is restricted to the anaplastic monomorphic subtype and correlates with the absence of KRAS alterations, whereas the pleomorphic giant cell subtype is characterized by KRAS alterations and intact SMARCB1 expression. Recognition and appropriate subtyping of these rare variants might become necessary for future therapeutic strategies.

Authors attain comparable or slightly higher rates of citation publishing in an open access journal (CytoJournal) compared to traditional cytopathology journals - A five year (2007-2011) experience

BACKGROUND

The era of Open Access (OA) publication, a platform which serves to better disseminate scientific knowledge, is upon us, as more OA journals are in existence than ever before. The idea that peer-reviewed OA publication leads to higher rates of citation has been put forth and shown to be true in several publications. This is a significant benefit to authors and is in addition to another relatively less obvious but highly critical component of the OA charter, i.e. retention of the copyright by the authors in the public domain. In this study, we analyzed the citation rates of OA and traditional non-OA publications specifically for authors in the field of cytopathology.

DESIGN

We compared the citation patterns for authors who had published in both OA and traditional non-OA peer-reviewed, scientific, cytopathology journals. Citations in an OA publication (CytoJournal) were analyzed comparatively with traditional non-OA cytopathology journals (Acta Cytologica, Cancer Cytopathology, Cytopathology, and Diagnostic Cytopathology) using the data from web of science citation analysis site (based on which the impact factors (IF) are calculated). After comparing citations per publication, as well as a time adjusted citation quotient (which takes into account the time since publication), we also analyzed the statistics after excluding the data for meeting abstracts.

RESULTS

Total 28 authors published 314 publications as articles and meeting abstracts (25 authors after excluding the abstracts). The rate of citation and time adjusted citation quotient were higher for OA in the group where abstracts were included (P < 0.05 for both). The rates were also slightly higher for OA than non-OA when the meeting abstracts were excluded, but the difference was statistically insignificant (P = 0.57 and P = 0.45).

CONCLUSION

We observed that for the same author, the publications in the OA journal attained a higher rate of citation than the publications in the traditional non-OA journals in the field of cytopathology over a 5 year period (2007-2011). However, this increase was statistically insignificant if the meeting abstracts were excluded from the analysis. Overall, the rates of citation for OA and non-OA were slightly higher to comparable.

Cytologic features of pancreatic adenocarcinoma with "vacuolated cell pattern." report of a case diagnosed by endoscopic ultrasound-guided fine-needle aspiration

The "vacuolated cell pattern" has only been recently described as a distinct morphologic variant of pancreatobiliary adenocarcinoma. Herein, we report the endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) cytologic features of a case of pancreatic adenocarcinoma with "vacuolated cell pattern" occurring in a 60-year-old man. The aspirate smears and cell block sections from the EUS-FNA of a 23.5 mm hypoechoic pancreatic head mass were highly cellular, showing variably-sized crowded three-dimensional cell clusters, flat sheets, and numerous highly atypical single cells. The background was bloody and showed necrotic debris, but no discernible mucus. The most striking feature of the aspirate was the presence of numerous very large (20-50 µm) vacuoles, occupying the entire cytoplasm, pushing the nuclei to the side and indenting them, that imparted a cribriform appearance to the sheets of neoplastic cells. The non-vacuolated neoplastic cells were large, had abundant dense (squamoid) cytoplasm, irregularly contoured hyperchromatic nuclei, and prominent macronucleoli. Histologic evaluation of the pancreatectomy specimen showed a "vacuolated cell pattern" adenocarcinoma composed of poorly formed glands, solid sheets, and infiltrating single cells with pleomorphic nuclei and large cytoplasmic vacuoles. To our knowledge, this is the first report describing the cytologic features of this rather uncommon morphologic variant of pancreatic adenocarcinoma. Recognition of this morphologic variant of pancreatic adenocarcinoma in ESU-FNA samples allows its differentiation from primary and metastatic signet-ring cell carcinomas.

Osteoclastic giant cell tumor of the pancreas

INTRODUCTION

Pancreatic giant cell tumors are rare, with an incidence of less than 1% of all pancreatic tumors. Osteoclastic giant cell tumor (OGCT) of the pancreas is one of the three types of PGCT, which are now classified as undifferentiated carcinoma with osteoclast-like giant cells.

PRESENTATION OF CASE

The patient is a 57 year old woman who presented with a 3 week history of epigastric pain and a palpable abdominal mass. Imaging studies revealed an 18 cm × 15 cm soft tissue mass with cystic components which involved the pancreas, stomach and spleen. Exploratory laparotomy with distal pancreatectomy, partial gastrectomy and splenectomy was performed. Histology revealed undifferentiated pancreatic carcinoma with osteoclast-like giant cells with production of osteoid and glandular elements.

DISCUSSION

OGCT of the pancreas resembles benign-appearing giant cell tumors of bone, and contain osteoclastic-like multinucleated cells and mononuclear cells. OGCTs display a less aggressive course with slow metastasis and lymph node spread compared to pancreatic adenocarcinoma. Due to the rarity of the cancer, there is a lack of prospective studies on treatment options. Surgical en-bloc resection is currently considered first line treatment. The role of adjuvant therapy with radiotherapy or chemotherapy has not been established.

CONCLUSION

Pancreatic giant cell tumors are rare pancreatic neoplasms with unique clinical and pathological characteristics. Osteoclastic giant cell tumors are the most favorable sub-type. Surgical en bloc resection is the first line treatment. Long-term follow-up of patients with these tumors is essential to compile a body of literature to help guide treatment.

Clinical outcomes for anaplastic pancreatic cancer: a population-based study

BACKGROUND

Anaplastic pancreatic cancer (APC) is a rare subtype of pancreatic ductal adenocarcinoma (PDA) that can carry a worse overall survival (OS) when compared with other variants. However, the presence of osteoclast-like giant cells (OCGCs) in APC specimens can predict improved OS. The aim of this study was to evaluate the OS of patients with APC (with and without OCGCs) compared with patients with other subtypes of PDA using a population-based registry.

STUDY DESIGN

We identified all patients in the Surveillance, Epidemiology and End Results (SEER) database with pathologically confirmed APC and PDA diagnosed between 1988 and 2008. Overall survival was evaluated using Kaplan-Meier and Cox proportional hazard regression.

RESULTS

The study cohort included 5,859 (94.3%) patients with PDA and 353 (5.7%) with APC. Overall survival for all patients with APC was significantly worse than for patients with PDA (hazard ratio [HR] = 1.9; 95% CI, 1.7-2.1; p < 0.001); however, in the subgroup of resected patients, APC (n = 81) had similar OS to PDA (n = 3,517) (HR = 0.9; 95% CI, 0.7-1.2; p = 0.37). Patients with APC tumors with OCGCs (n = 11) demonstrated improved OS when compared with all other APC variants without OCGCs (n = 342) (HR = 0.3; 95% CI, 0.1-0.7; p = 0.004), but this survival difference was not observed in the subgroup of resected patients (HR = 0.5; 95% CI, 0.2-1.4; p = 0.18).

CONCLUSIONS

Anaplastic pancreatic cancer is a rare malignancy with poor OS. The diagnosis of APC with OCGCs is predictive of improved OS compared with other patients with APC. This survival benefit, however, is not observed in patients with resected disease.

Cytology of the Pancreas: A Practical Review for Cytopathologists

Pancreatic cytopathology plays a critical role in the management of patients with cystic and solid pancreatic masses. The frequency of pancreatic fine-needle aspiration continues to increase and general surgical pathologists and cytopathologists need to be aware of the most commonly encountered entities as well as the pitfalls associated with gastrointestinal tract contaminants in endoscopic ultrasound-guided fine-needle aspiration. This article focuses on the most commonly encountered pancreatic lesions and the importance of correlation of cytologic features with clinical, radiologic, and ancillary studies for accurate diagnosis.

Recurrent acute pancreatitis and persistent hyperamylasemia as a presentation of pancreatic osteoclastic giant cell tumor: an unusual presentation of a rare tumor

Giant cell tumors of the pancreas are rare neoplasms divided into three forms: osteoclastic, pleomorphic, and mixed. We report an unusual case of a 62-year-old male presenting with recurrent acute pancreatitis and found to have a mass in the head of the pancreas on routine imaging. Endoscopic retrograde cholangiopancreatography showed a main pancreatic duct stricture, with brush cytology revealing the diagnosis of osteoclastic giant cell tumor of the pancreas. Whipple's procedure was successfully performed for resection of this tumor. and IAP.

A case report of undifferentiated carcinoma with osteoclast-like giant cells of the pancreas and literature review

Osteoclast-like giant cell tumors rarely arise in the pancreas. Here we report the case of a 78-year-old woman who was diagnosed with a well-defined 3 cm multilocular mass in the pancreatic body by the use of ultrasonography, computed tomography and magnetic resonance imaging. The rim and the septa of the tumor were well enhanced. The distal pancreas was removed with the spleen and the peripancreatic lymph nodes. Macroscopically, the mass was composed predominantly of a multilocular cystic tumor filled with hemorrhagic necrosis, and partly composed of solid components. A histopathological study showed a proliferation of multinucleated osteoclast-like giant cells and spindle cells. Although the predominant tumor cells were strongly positive for vimentin and CD68 and negative for epithelial markers, there were some sparsely scattered cytokeratin-positive neoplastic glands. Seventeen months after surgery, the patient is still alive and has had no recurrence. Below we review 32 cases of osteoclast-like giant cell tumor of the pancreas that have been reported in English literature since 2000.

Cytopathology of the pancreas: neoplastic and nonneoplastic entities

Endoscopic ultrasound-directed fine-needle aspiration is a minimally invasive technique for the biopsy of pancreatic cysts and mass lesions. The technique is associated with low morbidity and high diagnostic accuracy. Interpretation of cytologic material obtained from the pancreas is complex because of the large number of reactive processes and benign and malignant neoplasms arising within the pancreas. The cytologic appearances of a majority of pancreatic neoplasms are characteristic, allowing precise recognition of the type of neoplasm present. Whereas separation of neuroendocrine, acinar, and ductal neoplasms is usually straightforward, the greatest diagnostic challenge in pancreatic fine-needle aspiration is the separation of atypical epithelium secondary to chronic pancreatitis from well-differentiated ductal adenocarcinoma. Recently, a number of in situ lesions have been identified, complicating the cytologic diagnosis of pancreatic neoplasia. These noninvasive lesions include pancreatic intraepithelial neoplasia and intraductal papillary mucinous neoplasm.

Endoscopic ultrasound-guided fine-needle aspiration for the diagnosis of anaplastic pancreatic carcinoma: a single-center experience

OBJECTIVES

Anaplastic carcinoma of the pancreas (ACP) is an aggressive variant of ductal adenocarcinoma. The aim of this study was to describe a single-center experience with the use of endoscopic ultrasound (EUS) with or without fine-needle aspiration (FNA) for the diagnosis of ACP.

METHODS

The cytology and surgical pathology databases were searched for a diagnosis of ACP between 1992 and 2008. Demographic, clinical,surgical, radiographic, pathological, and EUS data were abstracted.

RESULTS

Thirteen patients with ACP were identified, which represented 0.8% of all pancreatic cancers diagnosed during the study period. Six of 13 patients had EUS. Features of these 6 tumors: median diameter of 42 mm (range, 20-100 mm), hypoechoic (n = 6), solid (n = 3) or mixed solid and cystic (n = 3), heterogeneous (n = 5) or homogeneous (n = 1),and well defined (n = 2) or poorly defined (n = 4) borders. Five underwent EUS-FNA of a pancreatic mass, and cytology demonstrated ACP in 4 and ductal adenocarcinoma in 1. The diagnosis of ACP was confirmed after surgical resection in 2 of these 5, including one in whom cytology demonstrated only adenocarcinoma. The sixth patient had EUS without FNA, and surgical pathology after distal pancreatectomy found ACP.

CONCLUSIONS

Anaplastic carcinoma of the pancreas has variable endosonographic features. Endoscopic ultrasound-FNA may assist in the cytological diagnosis of these tumors.