Surg Endosc (1992) 6:222-224
Surgical Endoscopy 9 Springer-Verlag New York Inc. 1992
Comparison between echo-guided fine-needle aspiration cytology and microhistology in diagnosing pancreatic masses L. Solmi 1, R. Muratori l, P. Bacchini 2, A. PrimeranC, and L. Gandolfi I i Gastroenterology Unit and 2 Department of Histopathology, Malpighi-S. Orsola Hospital, Via Albertoni 15, 1-40138 Bologna, Italy
Summary. E c h o - g u i d e d fine-needle aspiration biopsy o f p a n c r e a t i c m a s s e s is a well-established diagnostic p r o c e d u r e . H o w e v e r , there is no c o n s e n s u s as to the superiority o f c y t o l o g y or m i c r o h i s t o l o g y . W e c o m p a r e d the results of c y t o l o g y and microhistology in 50 c o n s e c u t i v e patients w h o u n d e r w e n t fineneedle aspiration b i o p s y for pancreatic masses. Aspirates w e r e positive for malignant disease in 42 patients; the o t h e r eight had c h r o n i c focal pancreatitis. In the 42 cases o f c a n c e r , c y t o l o g y p r o v i d e d c o n c l u s i v e results in 40 (95.2%); sampling w a s inadequate in two. Microhistology p r o v e d a c c u r a t e in 30 cases (71.4%); insufficient tissue was o b t a i n e d in 12, giving a statistically significant difference in f a v o r of c y t o l o g y (P < 0.01). In the eight patients with benign disease both techniques ruled out m a l i g n a n c y ; in five m i c r o h i s t o l o g y gave f u r t h e r indications confirming s u s p e c t e d c h r o n i c pancreatitis (fibrosis, l y m p h o c y t e and histiocyte-cell infiltrate). O u r results s h o w that c y t o l o g y is the m e t h o d o f c h o i c e in diagnosing p a n c r e a t i c c a r c i n o m a . Microhistology can be a useful adjunct in patients with susp e c t e d c h r o n i c pancreatitis.
Key words: F i n e - n e e d l e b i o p s y - P a n c r e a t i c m a s s e s Cytology - Microhistology
E c h o - g u i d e d fine-needle aspiration b i o p s y is especially useful in diagnosing p a n c r e a t i c m a s s e s imaged by ultras o n o g r a p h y but lacking definitive diagnosis. E c h o guided b i o p s y is well established [6, 8, 10, 11, 14, 16], but there is no a g r e e m e n t as to the superiority of cytolo g y or m i c r o h i s t o l o g y in the diagnosis of pancreatic m a s s e s [1-3, 5, 7, 9, 17]. This study aimed at c o m p a r i n g the results o f c y t o l o g y and m i c r o h i s t o l o g y in diagnosing p a n c r e a t i c m a s s e s in the g a s t r o e n t e r o l o g y unit o f o u r hospital.
Offprint requests to: L. Solmi
Patients, materials, and methods During the decade 1981-1991, 1,055 consecutive patients underwent echo-guided fine-needle aspiration biopsy. Of these, 74 patients (18 women) aged from 33 to 80 years (mean age 62.3 years) were referred for the diagnosis of pancreatic masses. The masses varied in size from 1.5 to 7 cm (mean 3 cm). Ultrasonography was performed using real-time equipment (Aloka SSD 256, Aloka Company, Japan; Ansaldo AUC 960 and AUC 450, Ansaldo Company, Italy) fitted first with linear probes and more recently with "convex" probes with a frequency of 3-3.5 MHz. In the first 24 patients of our series we used a Chiba needle alone as cutting needles were not available at that time. These cases were only included in the assessment of sensitivity and specificity of the whole series. In the last 50 consecutive patients, biopsy specimens for cytology and microhistology were taken at the same time with biopsy and cutting needles, respectively. The biopsy was performed free hand using 0.8-mm-caliber needles (21 G). The cytology specimen was obtained using Chiba needles connected with a 20-cc syringe in all cases. In the 43 patients who underwent biopsy for microhistology a modified Menghini-type cutting needle was used (Surecut, TSK, Japan). In seven cases a Tru-cut type cutting needle (Urocut, TSK, Japan) was adopted as we found this needle superior to Surecut in diagnosing liver lesions and it had proved equally safe [13]. For purposes of comparison using both needles, we performed four biopsies on each tumor mass (two with a Chiba needle and two with cutting needles). The techniques adopted for each needle have been widely reported in the literature [1, 8, 15]. Cytology specimens were stained by the May-Griinwald-Giemsa method while the hematoxylin-eosin technique was used for microhistology. Of the 50 patients biopsied with both needles, definitive diagnosis of carcinoma was made in 42 patients and focal chronic pancreatitis in eight. Diagnosis was confirmed at surgery in 28 cancer patients and three with chronic pancreatitis. Malignancy was confirmed at autopsy in nine patients. In the five patients with chronic pancreatitis still living who did not undergo surgery, diagnosis was confirmed by CT and ERCP as well as clinical, biochemical, and ultrasound followup for at least 6 months. Statistical analysis was performed using the X2 test with a significance of P < 0.05.
Results In patients with p a n c r e a t i c c a n c e r , c y t o l o g y gave an a c c u r a t e diagnosis in 40 out o f 42 cases; aspirates w e r e insufficient in t w o cases as only blood s m e a r s w e r e o b t a i n e d (Table 1). M i c r o h i s t o l o g y was positive in 30
223
Table 1. Comparison between fine-needle cytology and histology in diagnosing pancreatic masses Cytology
Histology
Final diagnosis
Malignant
Benign
Insuff. mat.
Malignant
Benign
Insuff. mat.
Malignant Benign
40 0
0 8
2 0
30 0
0 8"
12 0
a In five of these cases histology was diagnostic for chronic pancreatitis
out of 42 cases. Specimens were inadequate in 12, consisting of excessive blood contamination in ten and sparse fibrous material in two. These 12 patients included two not diagnosed by cytology. Cytological diagnosis was conclusive in 95.2% of cases, as was microhistology in 71.4%, with a statistically significant difference (P < 0.01). In the eight patients with pancreatitis, malignancy was ruled out by cytology and microhistology in all cases. While cytology only disclosed cells lacking malignant features, in five patients microhistology revealed a pancreatic epithelium free of malignant changes associated with abundant stromal fibers and lymphocyte and histiocyte cell infiltrate, strongly indicative of chronic pancreatitis.
Complications Complications were confined to a 300-cc peripancreatic hematoma encountered at surgery 10 days after biopsy in one patient with pancreatic adenocarcinoma. No symptoms worthy of note had been referred by the patient after biopsy nor were laboratory test values significantly changed. Biopsy had been straightforward and was performed with a Tru-cut fine cutting needle. This complication and the fact that the sample obtained was not superior to the Surecut specimen (unlike liver biopsies) led us to abandon the use of Tru-cut needles for pancreatic biopsies. Nine patients presented slightly elevated serum amylase on routine testing the day after biopsy without clinical signs of pancreatitis.
Discussion
Echo-guided fine-needle aspiration biopsy offers fast and accurate diagnosis of pancreatic masses imaged at ultrasonography. This method can differentiate malignant conditions from benign as focal chronic pancreatitis, which was once difficult to distinguish even with invasive techniques such as ERCP. The sensitivity of aspiration biopsy is well established in the literature. In our experience, currently totalling 74 pancreatic masses, sensitivity was 92% with a specificity of 100%. The positive predictive value was 100%; the negative value was lower at 83.3%. The choice between cytology and microhistology in the diagnosis of pancreatic masses is equivocal. Studies in the literature comparing the two techniques consist
of two reports published in 1987 by French authors [2, 18] based on small series of 19 and 24 cases of malignancy, respectively, each reaching opposite conclusions. A recent Danish study [5] compared the two methods in 100 patients and found cytology superior in the diagnosis of pancreatic masses, in agreement with our findings (Table 2). We also found cytology significantly more accurate than microhistology (P < 0.01). Microhistology failed to provide adequate specimens six times more often than cytology. This may have been due to the structure of the tumor mass with abundant fibrosis or necrosis, which gave inadequate specimens using cutting needles. If the sample is biopsied toward the periphery to avoid the necrotic central areas, the sample may only show signs of chronic pancreatitis or acute pancreatitis secondary to a centrally located carcinoma [5]. In our cases with insufficient microhistology samples, surgery disclosed highly fibrotic neoplasms. The lower incidence of inadequate specimens with cytology may be due to the different sampling technique using Chiba biopsy needles. Unlike cutting needles which are inserted in one movement, Chiba needles are vigorously agitated within the mass during each biopsy. Hence a larger tumoral area is examined with a greater likelihood of obtaining sufficient tissue fragments. Our findings favor the use of Chiba needles as opposed to Surecut in biopsies of the pancreas. The choice of needle is independent of the incidence of complications. In our series the only complication arose following biopsy with a Tru-cut needle. Nevertheless, in Smith's recent extensive survey of complications arising during echo-guided biopsy [12], most complications occurred after pancreatic biopsy using Chiba needles.
Table 2. Comparison between cytology and microhistology in diagnosing pancreatic masses Author
Chagnon et al. (1987) Vilgrain et al. (1987) Glenthoj et al. (1990) our results
No. cases
Sensitivity (%) Cytology
Microhistology
19
71
92
24
76.7
72
100 50
92 95.2
72 71.4
224
Although microhistology proved less accurate in this and other studies [7, 8, 10], it is an important technique in tissue typing for some rare neoplasms such as papilliferous carcinoma thanks to immunohistochemical staining which is not always feasible with cytology. Typing in these cases is crucial as papilliferous carcinoma is far less aggressive than adenocarcinoma and can usually be referred for surgical management. In neuroendocrine tumors of the pancreas, histology provides conclusive diagnosis not obtainable with cytology alone. Specimens can be examined by electronic microscopy, which offers more detailed information than inspecting cell fragments [7, 10]. Our series included a limited number of patients with benign disease but microhistology provided more information than cytology in five out of eight cases. Histological features were disclosed such as fibrosis and lymphocyte and monocyte cell infiltrate indicating chronic pancreatitis. According to Frable [4], cytology can also reveal features diagnostic for chronic pancreatitis such as inflammatory cells and fibroblastic fused cells, but this was not the case in our series. Inflammatory alterations to epithelial cells may lead to severe dysplasia, making differential diagnosis from carcinoma arduous. This was responsible for two false-positive diagnoses of malignancy reported by Hancke et al. in cytological specimens [7]. Microhistology offers a more thorough assessment avoiding errors of this type, albeit rare. In our experience, microhistology failed to offer more information than cytology in diagnosing pancreatic carcinoma and was a less-sensitive technique. In some benign cases, microhistology offered further detail for tissue typing, so it may prove a useful adjunct in patients with suspected chronic focal pancreatitis. Chiba needles and cytology preparations are cheaper than histology and cytology is faster and more sensitive, making it the method of choice in diagnosing pancreatic masses. References 1. Celle G, Savarino N, Biggi E, Manzi C, Ceppa P, Licio GR, Arcuri V (1986) Fine needle aspiration cytodiagnosis: a simple and safe procedure for cancer of the pancreas. Gastroenterol Clin Biol 10:545-548
2. Chagnon S, Cochand-Priallet B, Jacquenod P, Vilgrain N, Blery M (1987) Int6ret de la cytoponction associ6e ~t la micro-biopsie dans les masses solides du pancr6as. J Radiol 68:733-736 3. Cornud F, Vissuzaine C, Sibeit A, Lenoir S, Blangy S, Bocquet L, Benacerraf R (1985) Sensibilit6 de la ponction-biopsie ~t l'aiguille fine dans le diagnostic histologique des tumeurs malignes h6patiques et pancr6atiques. Gastroenterol Clin Biol 9: 47-50 4. Frable WJ (1983) Thin-needle aspiration biopsy. In: Bennington JL (ed) Major problems in pathology. WB Saunders, Philadelphia, pp 222-232 5. GlenthCj A, Sehested M, Torp-Pedersen S (1990) Ultrasonically guided histological and cytological fine needle biopsies of the pancreas. Reliability and reproducibility of diagnoses. Gut 31: 930-933 6. Hajdu EO, Kumari-Subaya S, Phillips G (1986) Ultrasonically guided percutaneous aspiration biopsy of the pancreas. Semin Diag Pathol 3:166-175 7. Hancke S, Holm HH, Kock F (1985) Ultrasonically guided puncture of pancreatic mass lesions. In: Holm HH, Kristensens JK (eds) Interventional ultrasound, Munksgaard, Copenhagen, pp 100-105 8. Kocjan G, Rode J, Lees WR (1989) Percutaneous fine needle aspiration cytology of the pancreas: advantages and pitfalls. J Clin Pathol 42:341-347 9. Lees WR, HaII-Craggs MA, Manhire A (1985) Five years experience of fine needle aspiration biopsy: 454 consecutive cases. Clin Radiol 36:517-520 10. Mitchell ML, Bittner Ca, Wills JS, Parker FP (1988). Fine needle aspiration cytology of the pancreas. A retrospective study of 73 cases. Acta Cytol 32:447-451 11. Scott Gazelle G, Haaga JR (1989) Guided percutaneous biopsy of intraabdominal lesions. AJR 153:929-935 12. Smith EH (1991) Complication of percutaneous abdominal fineneedle biopsy. Radiology 178:253-258 13. Solmi L, Gandolfi L, Muratori R, Leo P, Bacchini P (1987) Echo-guided fine needle biopsy of pancreatic masses. Am J Gastroenterol 8:744-748 14. Solmi L, Muratori R, Brambati M, Gandolfi L, (1989) Comparison between the 21-Gauge Urocut needle and the 21-Gauge Surecut needle in echo-guided percutaneous biopsy of neoplastic liver lesions. Surg Endosc 3:38-41 15. Taavitsainen M, Koivuniemi A, Bondestam S, Kivisaari L, Tierala E (1987) Ultrasonically guided fine-needle aspiration biopsy in focal pancreatic lesions. Acta Radiol 28:541-543 16. Torp-Pedersen S, Juul N, Vyberg M (1984) Histological sampling with a 23 gauge modified Menghini needle. Br J Radiol 57: 155-154 17. Tudway DC, Newman J, Chard MJ (1988) Ultrasound guided fine needle histological biopsies in the abdomen. Clin Radiol 39: 377-380 18. Vilgrain V, Anagnostopoulos C, Chagnon S, Bl6ry M (1987) Etude de 90 ponctions ~ l'aiguille fine ~t vis6e diagnostique de l'abdomen sup6rieur sous controle 6chographique. Apport de l'analyse cyto et histologique. J Radiol 68:35-38
Surgical Endoscopy 9 Springer-Verlag New York Inc. 1992
Comparison between echo-guided fine-needle aspiration cytology and microhistology in diagnosing pancreatic masses L. Solmi 1, R. Muratori l, P. Bacchini 2, A. PrimeranC, and L. Gandolfi I i Gastroenterology Unit and 2 Department of Histopathology, Malpighi-S. Orsola Hospital, Via Albertoni 15, 1-40138 Bologna, Italy
Summary. E c h o - g u i d e d fine-needle aspiration biopsy o f p a n c r e a t i c m a s s e s is a well-established diagnostic p r o c e d u r e . H o w e v e r , there is no c o n s e n s u s as to the superiority o f c y t o l o g y or m i c r o h i s t o l o g y . W e c o m p a r e d the results of c y t o l o g y and microhistology in 50 c o n s e c u t i v e patients w h o u n d e r w e n t fineneedle aspiration b i o p s y for pancreatic masses. Aspirates w e r e positive for malignant disease in 42 patients; the o t h e r eight had c h r o n i c focal pancreatitis. In the 42 cases o f c a n c e r , c y t o l o g y p r o v i d e d c o n c l u s i v e results in 40 (95.2%); sampling w a s inadequate in two. Microhistology p r o v e d a c c u r a t e in 30 cases (71.4%); insufficient tissue was o b t a i n e d in 12, giving a statistically significant difference in f a v o r of c y t o l o g y (P < 0.01). In the eight patients with benign disease both techniques ruled out m a l i g n a n c y ; in five m i c r o h i s t o l o g y gave f u r t h e r indications confirming s u s p e c t e d c h r o n i c pancreatitis (fibrosis, l y m p h o c y t e and histiocyte-cell infiltrate). O u r results s h o w that c y t o l o g y is the m e t h o d o f c h o i c e in diagnosing p a n c r e a t i c c a r c i n o m a . Microhistology can be a useful adjunct in patients with susp e c t e d c h r o n i c pancreatitis.
Key words: F i n e - n e e d l e b i o p s y - P a n c r e a t i c m a s s e s Cytology - Microhistology
E c h o - g u i d e d fine-needle aspiration b i o p s y is especially useful in diagnosing p a n c r e a t i c m a s s e s imaged by ultras o n o g r a p h y but lacking definitive diagnosis. E c h o guided b i o p s y is well established [6, 8, 10, 11, 14, 16], but there is no a g r e e m e n t as to the superiority of cytolo g y or m i c r o h i s t o l o g y in the diagnosis of pancreatic m a s s e s [1-3, 5, 7, 9, 17]. This study aimed at c o m p a r i n g the results o f c y t o l o g y and m i c r o h i s t o l o g y in diagnosing p a n c r e a t i c m a s s e s in the g a s t r o e n t e r o l o g y unit o f o u r hospital.
Offprint requests to: L. Solmi
Patients, materials, and methods During the decade 1981-1991, 1,055 consecutive patients underwent echo-guided fine-needle aspiration biopsy. Of these, 74 patients (18 women) aged from 33 to 80 years (mean age 62.3 years) were referred for the diagnosis of pancreatic masses. The masses varied in size from 1.5 to 7 cm (mean 3 cm). Ultrasonography was performed using real-time equipment (Aloka SSD 256, Aloka Company, Japan; Ansaldo AUC 960 and AUC 450, Ansaldo Company, Italy) fitted first with linear probes and more recently with "convex" probes with a frequency of 3-3.5 MHz. In the first 24 patients of our series we used a Chiba needle alone as cutting needles were not available at that time. These cases were only included in the assessment of sensitivity and specificity of the whole series. In the last 50 consecutive patients, biopsy specimens for cytology and microhistology were taken at the same time with biopsy and cutting needles, respectively. The biopsy was performed free hand using 0.8-mm-caliber needles (21 G). The cytology specimen was obtained using Chiba needles connected with a 20-cc syringe in all cases. In the 43 patients who underwent biopsy for microhistology a modified Menghini-type cutting needle was used (Surecut, TSK, Japan). In seven cases a Tru-cut type cutting needle (Urocut, TSK, Japan) was adopted as we found this needle superior to Surecut in diagnosing liver lesions and it had proved equally safe [13]. For purposes of comparison using both needles, we performed four biopsies on each tumor mass (two with a Chiba needle and two with cutting needles). The techniques adopted for each needle have been widely reported in the literature [1, 8, 15]. Cytology specimens were stained by the May-Griinwald-Giemsa method while the hematoxylin-eosin technique was used for microhistology. Of the 50 patients biopsied with both needles, definitive diagnosis of carcinoma was made in 42 patients and focal chronic pancreatitis in eight. Diagnosis was confirmed at surgery in 28 cancer patients and three with chronic pancreatitis. Malignancy was confirmed at autopsy in nine patients. In the five patients with chronic pancreatitis still living who did not undergo surgery, diagnosis was confirmed by CT and ERCP as well as clinical, biochemical, and ultrasound followup for at least 6 months. Statistical analysis was performed using the X2 test with a significance of P < 0.05.
Results In patients with p a n c r e a t i c c a n c e r , c y t o l o g y gave an a c c u r a t e diagnosis in 40 out o f 42 cases; aspirates w e r e insufficient in t w o cases as only blood s m e a r s w e r e o b t a i n e d (Table 1). M i c r o h i s t o l o g y was positive in 30
223
Table 1. Comparison between fine-needle cytology and histology in diagnosing pancreatic masses Cytology
Histology
Final diagnosis
Malignant
Benign
Insuff. mat.
Malignant
Benign
Insuff. mat.
Malignant Benign
40 0
0 8
2 0
30 0
0 8"
12 0
a In five of these cases histology was diagnostic for chronic pancreatitis
out of 42 cases. Specimens were inadequate in 12, consisting of excessive blood contamination in ten and sparse fibrous material in two. These 12 patients included two not diagnosed by cytology. Cytological diagnosis was conclusive in 95.2% of cases, as was microhistology in 71.4%, with a statistically significant difference (P < 0.01). In the eight patients with pancreatitis, malignancy was ruled out by cytology and microhistology in all cases. While cytology only disclosed cells lacking malignant features, in five patients microhistology revealed a pancreatic epithelium free of malignant changes associated with abundant stromal fibers and lymphocyte and histiocyte cell infiltrate, strongly indicative of chronic pancreatitis.
Complications Complications were confined to a 300-cc peripancreatic hematoma encountered at surgery 10 days after biopsy in one patient with pancreatic adenocarcinoma. No symptoms worthy of note had been referred by the patient after biopsy nor were laboratory test values significantly changed. Biopsy had been straightforward and was performed with a Tru-cut fine cutting needle. This complication and the fact that the sample obtained was not superior to the Surecut specimen (unlike liver biopsies) led us to abandon the use of Tru-cut needles for pancreatic biopsies. Nine patients presented slightly elevated serum amylase on routine testing the day after biopsy without clinical signs of pancreatitis.
Discussion
Echo-guided fine-needle aspiration biopsy offers fast and accurate diagnosis of pancreatic masses imaged at ultrasonography. This method can differentiate malignant conditions from benign as focal chronic pancreatitis, which was once difficult to distinguish even with invasive techniques such as ERCP. The sensitivity of aspiration biopsy is well established in the literature. In our experience, currently totalling 74 pancreatic masses, sensitivity was 92% with a specificity of 100%. The positive predictive value was 100%; the negative value was lower at 83.3%. The choice between cytology and microhistology in the diagnosis of pancreatic masses is equivocal. Studies in the literature comparing the two techniques consist
of two reports published in 1987 by French authors [2, 18] based on small series of 19 and 24 cases of malignancy, respectively, each reaching opposite conclusions. A recent Danish study [5] compared the two methods in 100 patients and found cytology superior in the diagnosis of pancreatic masses, in agreement with our findings (Table 2). We also found cytology significantly more accurate than microhistology (P < 0.01). Microhistology failed to provide adequate specimens six times more often than cytology. This may have been due to the structure of the tumor mass with abundant fibrosis or necrosis, which gave inadequate specimens using cutting needles. If the sample is biopsied toward the periphery to avoid the necrotic central areas, the sample may only show signs of chronic pancreatitis or acute pancreatitis secondary to a centrally located carcinoma [5]. In our cases with insufficient microhistology samples, surgery disclosed highly fibrotic neoplasms. The lower incidence of inadequate specimens with cytology may be due to the different sampling technique using Chiba biopsy needles. Unlike cutting needles which are inserted in one movement, Chiba needles are vigorously agitated within the mass during each biopsy. Hence a larger tumoral area is examined with a greater likelihood of obtaining sufficient tissue fragments. Our findings favor the use of Chiba needles as opposed to Surecut in biopsies of the pancreas. The choice of needle is independent of the incidence of complications. In our series the only complication arose following biopsy with a Tru-cut needle. Nevertheless, in Smith's recent extensive survey of complications arising during echo-guided biopsy [12], most complications occurred after pancreatic biopsy using Chiba needles.
Table 2. Comparison between cytology and microhistology in diagnosing pancreatic masses Author
Chagnon et al. (1987) Vilgrain et al. (1987) Glenthoj et al. (1990) our results
No. cases
Sensitivity (%) Cytology
Microhistology
19
71
92
24
76.7
72
100 50
92 95.2
72 71.4
224
Although microhistology proved less accurate in this and other studies [7, 8, 10], it is an important technique in tissue typing for some rare neoplasms such as papilliferous carcinoma thanks to immunohistochemical staining which is not always feasible with cytology. Typing in these cases is crucial as papilliferous carcinoma is far less aggressive than adenocarcinoma and can usually be referred for surgical management. In neuroendocrine tumors of the pancreas, histology provides conclusive diagnosis not obtainable with cytology alone. Specimens can be examined by electronic microscopy, which offers more detailed information than inspecting cell fragments [7, 10]. Our series included a limited number of patients with benign disease but microhistology provided more information than cytology in five out of eight cases. Histological features were disclosed such as fibrosis and lymphocyte and monocyte cell infiltrate indicating chronic pancreatitis. According to Frable [4], cytology can also reveal features diagnostic for chronic pancreatitis such as inflammatory cells and fibroblastic fused cells, but this was not the case in our series. Inflammatory alterations to epithelial cells may lead to severe dysplasia, making differential diagnosis from carcinoma arduous. This was responsible for two false-positive diagnoses of malignancy reported by Hancke et al. in cytological specimens [7]. Microhistology offers a more thorough assessment avoiding errors of this type, albeit rare. In our experience, microhistology failed to offer more information than cytology in diagnosing pancreatic carcinoma and was a less-sensitive technique. In some benign cases, microhistology offered further detail for tissue typing, so it may prove a useful adjunct in patients with suspected chronic focal pancreatitis. Chiba needles and cytology preparations are cheaper than histology and cytology is faster and more sensitive, making it the method of choice in diagnosing pancreatic masses. References 1. Celle G, Savarino N, Biggi E, Manzi C, Ceppa P, Licio GR, Arcuri V (1986) Fine needle aspiration cytodiagnosis: a simple and safe procedure for cancer of the pancreas. Gastroenterol Clin Biol 10:545-548
2. Chagnon S, Cochand-Priallet B, Jacquenod P, Vilgrain N, Blery M (1987) Int6ret de la cytoponction associ6e ~t la micro-biopsie dans les masses solides du pancr6as. J Radiol 68:733-736 3. Cornud F, Vissuzaine C, Sibeit A, Lenoir S, Blangy S, Bocquet L, Benacerraf R (1985) Sensibilit6 de la ponction-biopsie ~t l'aiguille fine dans le diagnostic histologique des tumeurs malignes h6patiques et pancr6atiques. Gastroenterol Clin Biol 9: 47-50 4. Frable WJ (1983) Thin-needle aspiration biopsy. In: Bennington JL (ed) Major problems in pathology. WB Saunders, Philadelphia, pp 222-232 5. GlenthCj A, Sehested M, Torp-Pedersen S (1990) Ultrasonically guided histological and cytological fine needle biopsies of the pancreas. Reliability and reproducibility of diagnoses. Gut 31: 930-933 6. Hajdu EO, Kumari-Subaya S, Phillips G (1986) Ultrasonically guided percutaneous aspiration biopsy of the pancreas. Semin Diag Pathol 3:166-175 7. Hancke S, Holm HH, Kock F (1985) Ultrasonically guided puncture of pancreatic mass lesions. In: Holm HH, Kristensens JK (eds) Interventional ultrasound, Munksgaard, Copenhagen, pp 100-105 8. Kocjan G, Rode J, Lees WR (1989) Percutaneous fine needle aspiration cytology of the pancreas: advantages and pitfalls. J Clin Pathol 42:341-347 9. Lees WR, HaII-Craggs MA, Manhire A (1985) Five years experience of fine needle aspiration biopsy: 454 consecutive cases. Clin Radiol 36:517-520 10. Mitchell ML, Bittner Ca, Wills JS, Parker FP (1988). Fine needle aspiration cytology of the pancreas. A retrospective study of 73 cases. Acta Cytol 32:447-451 11. Scott Gazelle G, Haaga JR (1989) Guided percutaneous biopsy of intraabdominal lesions. AJR 153:929-935 12. Smith EH (1991) Complication of percutaneous abdominal fineneedle biopsy. Radiology 178:253-258 13. Solmi L, Gandolfi L, Muratori R, Leo P, Bacchini P (1987) Echo-guided fine needle biopsy of pancreatic masses. Am J Gastroenterol 8:744-748 14. Solmi L, Muratori R, Brambati M, Gandolfi L, (1989) Comparison between the 21-Gauge Urocut needle and the 21-Gauge Surecut needle in echo-guided percutaneous biopsy of neoplastic liver lesions. Surg Endosc 3:38-41 15. Taavitsainen M, Koivuniemi A, Bondestam S, Kivisaari L, Tierala E (1987) Ultrasonically guided fine-needle aspiration biopsy in focal pancreatic lesions. Acta Radiol 28:541-543 16. Torp-Pedersen S, Juul N, Vyberg M (1984) Histological sampling with a 23 gauge modified Menghini needle. Br J Radiol 57: 155-154 17. Tudway DC, Newman J, Chard MJ (1988) Ultrasound guided fine needle histological biopsies in the abdomen. Clin Radiol 39: 377-380 18. Vilgrain V, Anagnostopoulos C, Chagnon S, Bl6ry M (1987) Etude de 90 ponctions ~ l'aiguille fine ~t vis6e diagnostique de l'abdomen sup6rieur sous controle 6chographique. Apport de l'analyse cyto et histologique. J Radiol 68:35-38
