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Reappraisal of endoscopic tissue diagnosis in secondary gastric lymphoma
123
Reappraisal of endoscopic tissue diagnosis in secondary gastric lymphoma G. Posner, C. ). Lightdale, M. Cooper, P. Sherlock, S. ). Winawer,
MD MD MD MD MD
New York, New York
Contrary to previously held views, gastric lymphomas often are amenable to tissue diagnosis at endoscopy. The authors succeeded in defining a diagnosis in 10 of 14 cases even through a majority of lesions were infiltrative in type. Biopsy and brush cytology were of complementary value. Cytologic washings did not add to the diagnostic yield. Patients with disseminated lymphoma who develop gastrointestinal signs or symptoms do not necessarily have gastrointestinal involvement with lymphoma. They may have a variety of benign complications including stress ulcers, fungal infection, or gastritis secondary to drugs or radiotherapy.' In addition, a new gastric tumor mass in such patients may be a second primary lesion. An accurate diagnosis is essential for effective management and early specific therapy. In many cases, tissue diagnosis of lymphoma made endoscopically may avoid diagnostic laparotomy and gastrotomy. However, the ability of the endoscopist to obtain a tissue diagnosis in cases of lymphoma involving the stomach has been considered poor. ' ·• This is in contrast to gastric and esophageal carcinoma where it is widely accepted that a high frequency of pathological diagnoses. can be made by endoscopic biopsy and cytology.' In recent years, with the advent of new instruments and technics, itwas our impression that the frequency of obtaini ng a positive tissue diagnosis in secondary lymphoma was surprisingly good. This report is a reappraisal of our endoscopic capability in documenting the presence of gastric involvement in this disease. METHODS We reviewed charts of patients who had proven gastric lymphoma that were endoscoped at Memorial SloanKettering Cancer Center from January 1971 to January 1974. The procedures were performed with the forward-viewing panendoscope (FV-7089P) made by the American Cystoscope Makers, Inc. Four biopsies and directed brush cytology were obtained in most cases where studies of blood coagulation and platelet counts were in acceptable ranges. Biopsies were obtained with standard mucosal cup biopsy forceps and placed in 10% formalin on porous gelatin sponge (Gelfoam). Directed brush cytology was obtained with a small bristle brush contained in a polyethylene sheath. The brush is passed inside its sheath through the biopsy channel of the endoscope and extended when the tip of the sheath is seen approaching the lesion. Lesions were brushed over the surface until bleeding was observed, and the brush was then withdrawn into the sheath before withdrawal through the endoscope. Smears of
the material on the brush were made on glass slides which were immediately fixed in 95% ethanol without air-drying. RESULTS There were 14 patients with proven secondary gastric lymphoma that were endoscoped, 7 males and 7 females ranging in age from 15 to 77 years (Table 1). The reasons for endoscopy included upper gastrointestinal bleeding, abdominal mass, abdominal pain, and evaluation of the extent of disease in patients previously diagnosed. Ten of the 14 patients had tissue diagnoses made at endoscopy (Figures 1,2). In 4 patients, attempts to make the diagnosis endoscopically failed, tissue being obtained at surgery in 1 patient and at autopsy in 3 others. In all 14 patients a malignant neoplasm of unknown type was diagnosed by endoscopic visualization. The most common appearance, seen in 10 patients, was large, thickened gastric folds. In 3 additional patients the folds appeared nodular as well. In 1 patient with reticulum cell sarcoma there was rigidity and a malignant-appearing ulcer, and in 1 patient with Hodgkin's disease there was an ulcerated mass. DISCUSSION Review of the literature suggests that obtaining tissue endoscopically in patients with lymphoma is difficult. Several small series have been reported where endoscopic biopsy and cytology were considered ancillary to visual description. ' ·• This is in contrast to the high diagnostic yield reported for similar technics in cases of gastric and esophageal carcinoma.' In cases of gastric adenocarcinoma, we have demonstrated that local tumor growth pattern is a major determinant in endoscopic tissue diagnosis.- In exophytic (protruding, polypoid) gastric carcinomas there were more positive results (16/18 cases) than in infiltrative gastric carcinomas (8/19 cases). Since most secondary lymphomas are infiltrative lesions, this was presumed to be the reason for the difficulty in obtaining tissue by mucosal biopsy and cytology in the past. In this series, however, using a modern 110 cm, endviewing fiberscope with full-tip maneuverability that allows direct biopsy aned cytology, our diagnostic yield was 10/14 (71 %), which compares favorably with our overall yield of 19/37 (65%) in gastric adenocarcinoma during the same
From the Gastroenterology Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, N.Y. 10021. This investigation was supported in part by an American Cancer Society Junior Faculty Fellowship Award (Dr. Lightdale) and by Training Program for Cancer Teaching and Research (CAOS 11 0) from the National Cancer Institute. Reprint requests: S. J. Winawer, M.D., Memorial Sloan-Kettering Cancer Center, 127S York Avenue, New York, N.Y. 10021. Volume 21, No.3, 1975
124
Table I
Endoscopic biopsy and cytology in proven secondary gastric lymphoma
age/sex
type
macro
observation
location
brush biopsy cytology
1.
38
M
RCS
infiltrating
large nodular folds
cardia
2.
59
M
RCS
infi Itrati ng
large nodular folds, erythema
antrum
+
3.
77
F
RCS
exophytic
mass
cardia
+
+
4.
68
F
RCS
infi Itrati ng
ulcer
body
5.
20
F
RCS
infi Itrati ng
large folds
body
a
+
6.
50
M
LSA
infi Itrati ng
large folds (localized)
body
a
+
7.
66
M
LSA
infi Itrati ng
large folds
body
+
a
8.
46
F
LSA
infi Itrati ng
large folds, erythema
cardia & body
+
+
9.
65
F
LSA
infi Itrating
large folds, ulcer erosions
cardia & body
10.
59
M
LSA
infi Itrating
large nodular folds
body
11.
53
F
LSA
infi Itrating
large folds with erosions
body
12.
15
F
LSA
infi Itrati ng
large folds
body
13.
53
M
HD
infi Itrati ng
erosions
antrum
14.
58
M
HD
exophytic
mass ulcer
cardia & body
Res = reticulum cell
+ +
+
+ 5/12 7/13 combined 10/14
sarcoma
LSA ~ lymphosarcoma HD = Hodgkin's disease o = nol performed
period. The 4 patients with lymphoma that had negative biopsies and cytology all had lesions that were infiltrative in type. In a previous report of endoscopic findings in patients with gastric lymphoma from this institution, a shorter, 80 cm instrument with only bidirectional tip control (Olympus EF) was utilized." Positive tissue was obtained in only 3/15 patients,
,
.
•
'"
T
l
t
...
\-" ~,
.....
Figure 1. Smear prepared from directed endoscopic brushing of area of suspected secondary gastric lymphoma. This single small malignant cell is representative of many such cells seen on this smear which were consistent with reticulum cell sarcoma. (Papanicolaou x 450.)
but histologic documentation was not pursued vigorously in all patients. Nelson and Lanza have also recently reversed their earlier opinion regarding a low yield of tissue diagnosis in gastric lymphoma during endoscopy. Using multiple 8-12 directed biopsies and re-examination in suspicious cases that are biopsy-negative, they reported positive biopsies in 86 per cent of cases.'O GASTROINTESTINAL ENDOSCOPY
125
The instrumentation advances that have facilitated our increased positive yield are directed brush cytology and a longer instrument with more precise tip control. In our patients with esophageal and gastric malignancy, brushing provided a diagnosis more often than did biopsy. In the group of 14 lymphoma patients reported here, there were 3 instances of positive brush cytology and negative biopsy. In 2 patients the situation was reversed. Both technics together proved complementary and provided the highest yield. In our hands, endoscopic cytological washings did not add to biopsy and directed brush cytology in obtaining malignant tissue. Among the 14 patients reported, washings were positive in only 4, all of whom were already diagnosed by either biopsy, brush cytology, or both. Others have similarly found gastric washings to be of low yield," and Nelson considered the technic almost uselessY This differs from the good results reported by Prolla and colleagues 13 who found positive washings in 27 of 39 patients (64%) with various forms of gastric lymphoma. Endoscopic lavage may have other potentials such as providing a means for obtaining measurable CEA and enzyme activity in gastric washings. 14 Our results indicate that with current endoscopes and directed biopsy and cytology technics, there is a good likelihood of obtaining a tissue diagnosis in gastric lymphoma. In cases where gastric lymphoma is suspected, an aggressive attempt to confirm a diagnosis using these technics is suggested.
REPERENCES 1. SHERLOCK
2. 3. 4.
5.
6. 7.
P,
WINAWER Sj,
GOLDSTEIN
Mj,
BRAGG
DG:
Malignant lymphoma of the gastrointestinal tract. Progress in Gastroenterology II, 367, 1970 DANAO SC, SCHUMAN BM: Gastroscopic features of primary lymphoma. Gastroenterology 60:816,1971 (Abstract) EHRLICH AN: Lymphoma of the stomach: a report of two cases with gastroscopic observations. Gastrointestinal Endoscopy 14:136, 1968 GROSSMAN E, WINAWER Sj: Diffuse gastrointestinal lymphosarcoma. Gastroscopic and proctoscopic observations. Gastrointestinal Endoscopy 16:202, 1970 NELSON RS, LANZA FL, BOTTIGLIERI NG: The "crater" ulcer -a possibly exclusive characteristic of reticulum cell sarcoma of the stomach. Gastroenterology 60:824, 1971 (Abstract) NELSON RS, LANZA FL: Endoscopy in the diagnosis of gastric lymphoma and sarcoma. Am I Gastroenterol 50:37, 1968 MORRISSEY jF: Gastrointestinal endoscopy. Gastroenterology 62:1241,1972
8. POSNER G, LIGHTDALE C, MELAMED M, SERLOCK P, WINAWER Sj:
9.
10.
11.
12. 13.
Importance of local tumor growth patterns in the endoscopic diagnosis of upper gastrointestinal cancer. Gastroenterology 64:785, 1973 (Abstract) KATZ 5, KLEIN MS, WINAWER Sj, SHERLOCK P: Disseminated lymphoma involving the stomach: correlation of endoscopy with directed cytology and biopsy. Am I Dig Dis 18:370, 1973 NELSON RS, LANZA Fl: The endoscopic diagnosis of gastric Iymphoma-Gross characteristics and histology. Gastrointestinal Endoscopy 20:183, 1974 (Abstract) VILARDELL F: Re-evaluation of cytologic methods in the diagnosis of malignant lesions of the stomach. Progress in Gastroenterology 1:129,1968 NELSON RS: Endoscopy in gastric cancer. Recent Results in Cancer Research 32:38, 1970 PROLLA]C, KOBAYASHI 5, KIRSNER IB: Cytology of malignant lymphomas of the stomach. Acta Cytol 14:291, 1970
14. WINAWER
Sj, FLEISHER M, MELAMED M, SHERLOCK P, DESCHNER E, SCHWARTZ M: Cytological, immunological (CEA),
and isotope labeling studies based on gastrointestinal endoscopic lavage. Gastroenterology 66:A-1461800, 1974 (Abstract)
Volume 21, No.3, 1975
Counsel to Authors GASTROINTESTINAL ENDOSCOPY seeks to publish original papers describing investigations and significant observations relating to the various endoscopic technics employed in the study of digestive diseases. Descriptions of new instruments or methods, innovative applications of endoscopy, analyses of experience, and extraordinary case reports are welcome subjects. Readers who are piqued or prodded by published articles are encouraged to submit brief comments that the Editor may include in the "Reflex" section. Announcements of postgraduate courses, new facilities, cooperative studies and other items of interest to endoscopists are invited. Address typescripts and editorial correspondence to the editor. Typescripts should be submitted in duplicate on white paper of standard (8 112 x II inches) size. All copy, including footnotes, references, and captions, should be doubLe spaced with generous margins. The title page should include the author's names, the institution where the work was performed, and the name and address to which requests for reprints should be sent. Illustrations, including photographs and charts, should be submitted as glossy prints not less than 5 x 7 inches, preferably of uniform size. These must be unmounted and clearly labeled on the back, LightLy in penciL, to indicate first author's name, figure number, and top of illustration. Radiographs and endoscopic photographs must be of high contrast for proper reproduction. A reasonable number of pertinent illustrations in black and white can be allowed without charge. Color reproduction can be arranged at cost to the author. References should be indicated by consecutive numbers in the text and enumerated at the end of the paper in the same order. Each reference should conform to the following example: Scope GE, Optic F: What we saw. Gastroenterology 50:1001,1962. All authors should be listed (not "et al. "). Abbreviations of journal names are to be used as in Index Medicus.
Helpful information pertaining to the preparation of scientific articles will be found in StyLe ManuaL for BioLogical Journals, Ed. 2, published by American Institute of Biological Sciences, 3900 Wisconsin Ave., N.W., Washington, D.C. 20016. Galley proofs will be sent to the author for necessary corrections with the understanding that they are to be promptly returned. Reprints should be ordered when galley proof is returned. A purchase form will be furnished. Authors are reminded to retain in their own files a copy of the typescript and illustrations submitted.
Reappraisal of endoscopic tissue diagnosis in secondary gastric lymphoma G. Posner, C. ). Lightdale, M. Cooper, P. Sherlock, S. ). Winawer,
MD MD MD MD MD
New York, New York
Contrary to previously held views, gastric lymphomas often are amenable to tissue diagnosis at endoscopy. The authors succeeded in defining a diagnosis in 10 of 14 cases even through a majority of lesions were infiltrative in type. Biopsy and brush cytology were of complementary value. Cytologic washings did not add to the diagnostic yield. Patients with disseminated lymphoma who develop gastrointestinal signs or symptoms do not necessarily have gastrointestinal involvement with lymphoma. They may have a variety of benign complications including stress ulcers, fungal infection, or gastritis secondary to drugs or radiotherapy.' In addition, a new gastric tumor mass in such patients may be a second primary lesion. An accurate diagnosis is essential for effective management and early specific therapy. In many cases, tissue diagnosis of lymphoma made endoscopically may avoid diagnostic laparotomy and gastrotomy. However, the ability of the endoscopist to obtain a tissue diagnosis in cases of lymphoma involving the stomach has been considered poor. ' ·• This is in contrast to gastric and esophageal carcinoma where it is widely accepted that a high frequency of pathological diagnoses. can be made by endoscopic biopsy and cytology.' In recent years, with the advent of new instruments and technics, itwas our impression that the frequency of obtaini ng a positive tissue diagnosis in secondary lymphoma was surprisingly good. This report is a reappraisal of our endoscopic capability in documenting the presence of gastric involvement in this disease. METHODS We reviewed charts of patients who had proven gastric lymphoma that were endoscoped at Memorial SloanKettering Cancer Center from January 1971 to January 1974. The procedures were performed with the forward-viewing panendoscope (FV-7089P) made by the American Cystoscope Makers, Inc. Four biopsies and directed brush cytology were obtained in most cases where studies of blood coagulation and platelet counts were in acceptable ranges. Biopsies were obtained with standard mucosal cup biopsy forceps and placed in 10% formalin on porous gelatin sponge (Gelfoam). Directed brush cytology was obtained with a small bristle brush contained in a polyethylene sheath. The brush is passed inside its sheath through the biopsy channel of the endoscope and extended when the tip of the sheath is seen approaching the lesion. Lesions were brushed over the surface until bleeding was observed, and the brush was then withdrawn into the sheath before withdrawal through the endoscope. Smears of
the material on the brush were made on glass slides which were immediately fixed in 95% ethanol without air-drying. RESULTS There were 14 patients with proven secondary gastric lymphoma that were endoscoped, 7 males and 7 females ranging in age from 15 to 77 years (Table 1). The reasons for endoscopy included upper gastrointestinal bleeding, abdominal mass, abdominal pain, and evaluation of the extent of disease in patients previously diagnosed. Ten of the 14 patients had tissue diagnoses made at endoscopy (Figures 1,2). In 4 patients, attempts to make the diagnosis endoscopically failed, tissue being obtained at surgery in 1 patient and at autopsy in 3 others. In all 14 patients a malignant neoplasm of unknown type was diagnosed by endoscopic visualization. The most common appearance, seen in 10 patients, was large, thickened gastric folds. In 3 additional patients the folds appeared nodular as well. In 1 patient with reticulum cell sarcoma there was rigidity and a malignant-appearing ulcer, and in 1 patient with Hodgkin's disease there was an ulcerated mass. DISCUSSION Review of the literature suggests that obtaining tissue endoscopically in patients with lymphoma is difficult. Several small series have been reported where endoscopic biopsy and cytology were considered ancillary to visual description. ' ·• This is in contrast to the high diagnostic yield reported for similar technics in cases of gastric and esophageal carcinoma.' In cases of gastric adenocarcinoma, we have demonstrated that local tumor growth pattern is a major determinant in endoscopic tissue diagnosis.- In exophytic (protruding, polypoid) gastric carcinomas there were more positive results (16/18 cases) than in infiltrative gastric carcinomas (8/19 cases). Since most secondary lymphomas are infiltrative lesions, this was presumed to be the reason for the difficulty in obtaining tissue by mucosal biopsy and cytology in the past. In this series, however, using a modern 110 cm, endviewing fiberscope with full-tip maneuverability that allows direct biopsy aned cytology, our diagnostic yield was 10/14 (71 %), which compares favorably with our overall yield of 19/37 (65%) in gastric adenocarcinoma during the same
From the Gastroenterology Service, Department of Medicine, Memorial Sloan-Kettering Cancer Center, New York, N.Y. 10021. This investigation was supported in part by an American Cancer Society Junior Faculty Fellowship Award (Dr. Lightdale) and by Training Program for Cancer Teaching and Research (CAOS 11 0) from the National Cancer Institute. Reprint requests: S. J. Winawer, M.D., Memorial Sloan-Kettering Cancer Center, 127S York Avenue, New York, N.Y. 10021. Volume 21, No.3, 1975
124
Table I
Endoscopic biopsy and cytology in proven secondary gastric lymphoma
age/sex
type
macro
observation
location
brush biopsy cytology
1.
38
M
RCS
infiltrating
large nodular folds
cardia
2.
59
M
RCS
infi Itrati ng
large nodular folds, erythema
antrum
+
3.
77
F
RCS
exophytic
mass
cardia
+
+
4.
68
F
RCS
infi Itrati ng
ulcer
body
5.
20
F
RCS
infi Itrati ng
large folds
body
a
+
6.
50
M
LSA
infi Itrati ng
large folds (localized)
body
a
+
7.
66
M
LSA
infi Itrati ng
large folds
body
+
a
8.
46
F
LSA
infi Itrati ng
large folds, erythema
cardia & body
+
+
9.
65
F
LSA
infi Itrating
large folds, ulcer erosions
cardia & body
10.
59
M
LSA
infi Itrating
large nodular folds
body
11.
53
F
LSA
infi Itrating
large folds with erosions
body
12.
15
F
LSA
infi Itrati ng
large folds
body
13.
53
M
HD
infi Itrati ng
erosions
antrum
14.
58
M
HD
exophytic
mass ulcer
cardia & body
Res = reticulum cell
+ +
+
+ 5/12 7/13 combined 10/14
sarcoma
LSA ~ lymphosarcoma HD = Hodgkin's disease o = nol performed
period. The 4 patients with lymphoma that had negative biopsies and cytology all had lesions that were infiltrative in type. In a previous report of endoscopic findings in patients with gastric lymphoma from this institution, a shorter, 80 cm instrument with only bidirectional tip control (Olympus EF) was utilized." Positive tissue was obtained in only 3/15 patients,
,
.
•
'"
T
l
t
...
\-" ~,
.....
Figure 1. Smear prepared from directed endoscopic brushing of area of suspected secondary gastric lymphoma. This single small malignant cell is representative of many such cells seen on this smear which were consistent with reticulum cell sarcoma. (Papanicolaou x 450.)
but histologic documentation was not pursued vigorously in all patients. Nelson and Lanza have also recently reversed their earlier opinion regarding a low yield of tissue diagnosis in gastric lymphoma during endoscopy. Using multiple 8-12 directed biopsies and re-examination in suspicious cases that are biopsy-negative, they reported positive biopsies in 86 per cent of cases.'O GASTROINTESTINAL ENDOSCOPY
125
The instrumentation advances that have facilitated our increased positive yield are directed brush cytology and a longer instrument with more precise tip control. In our patients with esophageal and gastric malignancy, brushing provided a diagnosis more often than did biopsy. In the group of 14 lymphoma patients reported here, there were 3 instances of positive brush cytology and negative biopsy. In 2 patients the situation was reversed. Both technics together proved complementary and provided the highest yield. In our hands, endoscopic cytological washings did not add to biopsy and directed brush cytology in obtaining malignant tissue. Among the 14 patients reported, washings were positive in only 4, all of whom were already diagnosed by either biopsy, brush cytology, or both. Others have similarly found gastric washings to be of low yield," and Nelson considered the technic almost uselessY This differs from the good results reported by Prolla and colleagues 13 who found positive washings in 27 of 39 patients (64%) with various forms of gastric lymphoma. Endoscopic lavage may have other potentials such as providing a means for obtaining measurable CEA and enzyme activity in gastric washings. 14 Our results indicate that with current endoscopes and directed biopsy and cytology technics, there is a good likelihood of obtaining a tissue diagnosis in gastric lymphoma. In cases where gastric lymphoma is suspected, an aggressive attempt to confirm a diagnosis using these technics is suggested.
REPERENCES 1. SHERLOCK
2. 3. 4.
5.
6. 7.
P,
WINAWER Sj,
GOLDSTEIN
Mj,
BRAGG
DG:
Malignant lymphoma of the gastrointestinal tract. Progress in Gastroenterology II, 367, 1970 DANAO SC, SCHUMAN BM: Gastroscopic features of primary lymphoma. Gastroenterology 60:816,1971 (Abstract) EHRLICH AN: Lymphoma of the stomach: a report of two cases with gastroscopic observations. Gastrointestinal Endoscopy 14:136, 1968 GROSSMAN E, WINAWER Sj: Diffuse gastrointestinal lymphosarcoma. Gastroscopic and proctoscopic observations. Gastrointestinal Endoscopy 16:202, 1970 NELSON RS, LANZA FL, BOTTIGLIERI NG: The "crater" ulcer -a possibly exclusive characteristic of reticulum cell sarcoma of the stomach. Gastroenterology 60:824, 1971 (Abstract) NELSON RS, LANZA FL: Endoscopy in the diagnosis of gastric lymphoma and sarcoma. Am I Gastroenterol 50:37, 1968 MORRISSEY jF: Gastrointestinal endoscopy. Gastroenterology 62:1241,1972
8. POSNER G, LIGHTDALE C, MELAMED M, SERLOCK P, WINAWER Sj:
9.
10.
11.
12. 13.
Importance of local tumor growth patterns in the endoscopic diagnosis of upper gastrointestinal cancer. Gastroenterology 64:785, 1973 (Abstract) KATZ 5, KLEIN MS, WINAWER Sj, SHERLOCK P: Disseminated lymphoma involving the stomach: correlation of endoscopy with directed cytology and biopsy. Am I Dig Dis 18:370, 1973 NELSON RS, LANZA Fl: The endoscopic diagnosis of gastric Iymphoma-Gross characteristics and histology. Gastrointestinal Endoscopy 20:183, 1974 (Abstract) VILARDELL F: Re-evaluation of cytologic methods in the diagnosis of malignant lesions of the stomach. Progress in Gastroenterology 1:129,1968 NELSON RS: Endoscopy in gastric cancer. Recent Results in Cancer Research 32:38, 1970 PROLLA]C, KOBAYASHI 5, KIRSNER IB: Cytology of malignant lymphomas of the stomach. Acta Cytol 14:291, 1970
14. WINAWER
Sj, FLEISHER M, MELAMED M, SHERLOCK P, DESCHNER E, SCHWARTZ M: Cytological, immunological (CEA),
and isotope labeling studies based on gastrointestinal endoscopic lavage. Gastroenterology 66:A-1461800, 1974 (Abstract)
Volume 21, No.3, 1975
Counsel to Authors GASTROINTESTINAL ENDOSCOPY seeks to publish original papers describing investigations and significant observations relating to the various endoscopic technics employed in the study of digestive diseases. Descriptions of new instruments or methods, innovative applications of endoscopy, analyses of experience, and extraordinary case reports are welcome subjects. Readers who are piqued or prodded by published articles are encouraged to submit brief comments that the Editor may include in the "Reflex" section. Announcements of postgraduate courses, new facilities, cooperative studies and other items of interest to endoscopists are invited. Address typescripts and editorial correspondence to the editor. Typescripts should be submitted in duplicate on white paper of standard (8 112 x II inches) size. All copy, including footnotes, references, and captions, should be doubLe spaced with generous margins. The title page should include the author's names, the institution where the work was performed, and the name and address to which requests for reprints should be sent. Illustrations, including photographs and charts, should be submitted as glossy prints not less than 5 x 7 inches, preferably of uniform size. These must be unmounted and clearly labeled on the back, LightLy in penciL, to indicate first author's name, figure number, and top of illustration. Radiographs and endoscopic photographs must be of high contrast for proper reproduction. A reasonable number of pertinent illustrations in black and white can be allowed without charge. Color reproduction can be arranged at cost to the author. References should be indicated by consecutive numbers in the text and enumerated at the end of the paper in the same order. Each reference should conform to the following example: Scope GE, Optic F: What we saw. Gastroenterology 50:1001,1962. All authors should be listed (not "et al. "). Abbreviations of journal names are to be used as in Index Medicus.
Helpful information pertaining to the preparation of scientific articles will be found in StyLe ManuaL for BioLogical Journals, Ed. 2, published by American Institute of Biological Sciences, 3900 Wisconsin Ave., N.W., Washington, D.C. 20016. Galley proofs will be sent to the author for necessary corrections with the understanding that they are to be promptly returned. Reprints should be ordered when galley proof is returned. A purchase form will be furnished. Authors are reminded to retain in their own files a copy of the typescript and illustrations submitted.