Comment
Non-specific abdominal pain: the resource implications While it is important to reduce the number of patients unnecessarily admitted to hospital with non-specific abdominal pain (NSAP), particularly in the younger group of patients, as discussed by Sheridan et al. (Annals, May 1992, vol 74, p181), it is equally important to recognise that other conditions may masquerade as NSAP. Selective laparoscopy in those patients in whom the decision to operate is uncertain can reduce the overall incidence of NSAP (in all patients admitted with acute abdominal pain) to as low as 24% (1) compared with other studies where the figure remains above 40% (2). This reduction in the incidence of NSAP is associated with an increase in the detection of other conditions such as pelvic inflammatory disease, a diagnosis which, if undetected, may have important late sequelae (3). Likewise, in older patients (not included in Sheridan's study) underlying malignant conditions may occur in up to 10% of patients initially diagnosed as NSAP (4). Reduction in the admission rate or hospital stay for NSAP can undoubtedly be achieved by the methods suggested by Sheridan et al., in particular improved clinical assessment and ultrasonography, but it is important not to dismiss the undoubted contributions available from peritoneal lavage (5) and peritoneal cytology (6). Both these techniques can easily be performed at an early stage in the patient's assessment, if necessary in the casualty department, to help differentiate those patients who may have NSAP from those with an acute inflammatory process within the peritoneal cavity. A combination of peritoneal cytology and selective laparoscopy has also been shown to be of value (7) and both should now play an integral part in the assessment of patients with acute abdominal pain, not only to reduce the incidence of NSAP but also to improve the overall management of the acute abdomen. SIMON PATERSON-BROWN MPhil FRCS Senior Registrar JEREMY N THOMPSON MA MChir FRCS Senior Lecturer The Royal Postgraduate Medical School London
References I Paterson-Brown S. The acute abdomen: the role of laparoscopy. In: Williamson RCN, Thompson JN eds. Gastrointestinal Emergencies, Part I. London: Bailiere Tindall, 1991:691-703. 2 Gray DWR, Collin J. Non-specific abdominal pain as a cause of acute admission to hospital. Br j Surg 1987;74:239-42. 3 Pearce JM. Pelvic inflammatory disease. Br Med J 1990;
375
Carcinoma of the major salivary glands We read with interest the paper by Afify and Maynard (Annals, May 1992, vol 74, p186). They point out the usefulness of dividing salivary gland carcinomas into low-grade and highgrade as defined by routine histology, particularly with respect to planning radical surgery. However, they have failed to mention the major problem when planning surgery along the criterion of histological grade-namely that the sample taken for histology, in particular frozen section, may be unrepresentative. Indeed, there is no reason to believe it is representative, unless the whole specimen is examined, clearly impossible in frozen sections, and too involved and time-consuming in routine histological analysis. What is needed is an in vivo method of assessing the whole tumour preoperatively, which will allow an accurate assessment of 'whole tumour proliferation rate'. This may be possible in the relatively near future with the development of a positronemitting thymidine molecule-C-11 thymidine. Thymidine is a a molecule that is incorporated into DNA metabolism, and has been used in the past to measure DNA proliferation rate in vitro, using 3-H (tritiated) thymidine, a beta radiation emitter (1). Because a positron-emitting source allows the resultant gamma irradiation to be detected extracorporeally (2), thymidine uptake can now be measured in vivo, using a Positron Emission Tomography scanner (3), and hence an extremely accurate 'whole tumour proliferation rate' measurement becomes a possibility. This work is currently in the development stage, and although recent developments such as the flow cytometric analysis of tumour ploidy and uptake of Proliferating Cell Nuclear Antigen (PCNA) may improve the accuracy of identification of high- and low-grade tumours over basic histology and tritiated thymidine studies (4), we are still waiting for a low morbidity, extracorporeal in vivo test such as C-11 thymidine PET to accurately assess these tumours before radical treatment is instigated. M G DILKES FRCS FRCSEd Lecturer in ENT Surgery The Royal London Hospital Whitechapel, London P G RUSSELL Medical Student The London Hospital Medical College Whitechapel, London T JONES DSc Assistant Director, MRC PET Facility The Royal Postgraduate Medical School London
300;1090-91. 4 de Dombal FT, Matharu SS, Staniland JR et al. Presentation of cancer to hospital as 'acute abdominal pain'. Br J Surg 1980; 67:413-16. S Hoffman J, Lanng C, Shokouh-Amiri MH. Peritoneal lavage in the diagnosis of acute peritonitis. Am J Surg 1988;155: 359-60. 6 Stewart RJ, Gupta RK, Purdie GL, Isbister WH. Fine-catheter aspiration cytology of peritoneal cavity improves decision-making about difficult cases of acute abdominal pain. Lancet 1986;2:1414-15 7 Baigrie RJ, Saidan Z, Scott-Coombes D et al. The role of fine catheter peritoneal cytology and laparoscopy in the management of acute abdominal pain. BrJt Surg 1991;78:167-70.
References I Steel GG. Growth Kinetics of Tumours. Oxford: Clarendon Press, 1977. 2 Frackowiak RSJ, Jones T. PET scanning. Br Med J 1989; 298:693-4 3 Martiat P, Ferrant A, Labar D et al. In vivo measurement of carbon-Il thymidine uptake in non-Hodgkin's lymphoma using positron emission tomography. J Nucl Med 1988; 29:1633-7. 4 Galand P, Degraef C. Cyclin/PCNA immunostaining as an alternative to tritiated thymidine pulse labelling for marking S phase cells in paraffin sections from animal and human tissues. Cell Tissue Kinet i989;22:383-92.
Non-specific abdominal pain: the resource implications While it is important to reduce the number of patients unnecessarily admitted to hospital with non-specific abdominal pain (NSAP), particularly in the younger group of patients, as discussed by Sheridan et al. (Annals, May 1992, vol 74, p181), it is equally important to recognise that other conditions may masquerade as NSAP. Selective laparoscopy in those patients in whom the decision to operate is uncertain can reduce the overall incidence of NSAP (in all patients admitted with acute abdominal pain) to as low as 24% (1) compared with other studies where the figure remains above 40% (2). This reduction in the incidence of NSAP is associated with an increase in the detection of other conditions such as pelvic inflammatory disease, a diagnosis which, if undetected, may have important late sequelae (3). Likewise, in older patients (not included in Sheridan's study) underlying malignant conditions may occur in up to 10% of patients initially diagnosed as NSAP (4). Reduction in the admission rate or hospital stay for NSAP can undoubtedly be achieved by the methods suggested by Sheridan et al., in particular improved clinical assessment and ultrasonography, but it is important not to dismiss the undoubted contributions available from peritoneal lavage (5) and peritoneal cytology (6). Both these techniques can easily be performed at an early stage in the patient's assessment, if necessary in the casualty department, to help differentiate those patients who may have NSAP from those with an acute inflammatory process within the peritoneal cavity. A combination of peritoneal cytology and selective laparoscopy has also been shown to be of value (7) and both should now play an integral part in the assessment of patients with acute abdominal pain, not only to reduce the incidence of NSAP but also to improve the overall management of the acute abdomen. SIMON PATERSON-BROWN MPhil FRCS Senior Registrar JEREMY N THOMPSON MA MChir FRCS Senior Lecturer The Royal Postgraduate Medical School London
References I Paterson-Brown S. The acute abdomen: the role of laparoscopy. In: Williamson RCN, Thompson JN eds. Gastrointestinal Emergencies, Part I. London: Bailiere Tindall, 1991:691-703. 2 Gray DWR, Collin J. Non-specific abdominal pain as a cause of acute admission to hospital. Br j Surg 1987;74:239-42. 3 Pearce JM. Pelvic inflammatory disease. Br Med J 1990;
375
Carcinoma of the major salivary glands We read with interest the paper by Afify and Maynard (Annals, May 1992, vol 74, p186). They point out the usefulness of dividing salivary gland carcinomas into low-grade and highgrade as defined by routine histology, particularly with respect to planning radical surgery. However, they have failed to mention the major problem when planning surgery along the criterion of histological grade-namely that the sample taken for histology, in particular frozen section, may be unrepresentative. Indeed, there is no reason to believe it is representative, unless the whole specimen is examined, clearly impossible in frozen sections, and too involved and time-consuming in routine histological analysis. What is needed is an in vivo method of assessing the whole tumour preoperatively, which will allow an accurate assessment of 'whole tumour proliferation rate'. This may be possible in the relatively near future with the development of a positronemitting thymidine molecule-C-11 thymidine. Thymidine is a a molecule that is incorporated into DNA metabolism, and has been used in the past to measure DNA proliferation rate in vitro, using 3-H (tritiated) thymidine, a beta radiation emitter (1). Because a positron-emitting source allows the resultant gamma irradiation to be detected extracorporeally (2), thymidine uptake can now be measured in vivo, using a Positron Emission Tomography scanner (3), and hence an extremely accurate 'whole tumour proliferation rate' measurement becomes a possibility. This work is currently in the development stage, and although recent developments such as the flow cytometric analysis of tumour ploidy and uptake of Proliferating Cell Nuclear Antigen (PCNA) may improve the accuracy of identification of high- and low-grade tumours over basic histology and tritiated thymidine studies (4), we are still waiting for a low morbidity, extracorporeal in vivo test such as C-11 thymidine PET to accurately assess these tumours before radical treatment is instigated. M G DILKES FRCS FRCSEd Lecturer in ENT Surgery The Royal London Hospital Whitechapel, London P G RUSSELL Medical Student The London Hospital Medical College Whitechapel, London T JONES DSc Assistant Director, MRC PET Facility The Royal Postgraduate Medical School London
300;1090-91. 4 de Dombal FT, Matharu SS, Staniland JR et al. Presentation of cancer to hospital as 'acute abdominal pain'. Br J Surg 1980; 67:413-16. S Hoffman J, Lanng C, Shokouh-Amiri MH. Peritoneal lavage in the diagnosis of acute peritonitis. Am J Surg 1988;155: 359-60. 6 Stewart RJ, Gupta RK, Purdie GL, Isbister WH. Fine-catheter aspiration cytology of peritoneal cavity improves decision-making about difficult cases of acute abdominal pain. Lancet 1986;2:1414-15 7 Baigrie RJ, Saidan Z, Scott-Coombes D et al. The role of fine catheter peritoneal cytology and laparoscopy in the management of acute abdominal pain. BrJt Surg 1991;78:167-70.
References I Steel GG. Growth Kinetics of Tumours. Oxford: Clarendon Press, 1977. 2 Frackowiak RSJ, Jones T. PET scanning. Br Med J 1989; 298:693-4 3 Martiat P, Ferrant A, Labar D et al. In vivo measurement of carbon-Il thymidine uptake in non-Hodgkin's lymphoma using positron emission tomography. J Nucl Med 1988; 29:1633-7. 4 Galand P, Degraef C. Cyclin/PCNA immunostaining as an alternative to tritiated thymidine pulse labelling for marking S phase cells in paraffin sections from animal and human tissues. Cell Tissue Kinet i989;22:383-92.
