Hyperamylasaemia: not the usual suspects
1 Department of Biochemical Medicine, Ninewells Hospital, Dundee,2 Centre for Brain Injury Rehabilitation, Royal Victoria Hospital, Dundee,3 Department of Histopathology, Ninewells Hospital, Dundee
Introduction
Interpretation of abnormally high serum amylase activity is not always straightforward. Sometimes, as here, patients are erroneously labelled as having pancreatitis despite the absence of clinical features to support this diagnosis. Such assumptions may affect the interpretation of investigations.
, 百拇医药
Case report
A 53 year old woman was admitted to hospital, initially with a dense hemiparesis and dysarthria because of a left middle cerebral infarct. At the time of admission, she was recovering from a recent myocardial infarction. She was not known to be diabetic.
About six weeks after admission she complained of several episodes of vomiting. Routine haematology and biochemistry investigations were unremarkable apart from serum amylase activity of 1730 U/l (reference interval 0-100 U/l). This result immediately prompted surgical review. The surgical senior house officer diagnosed acute pancreatitis. A few days later the surgical registrar confirmed this clinical impression, although, in the complete absence of abdominal pain, the pancreatitis was described as mild. Multiple repeated measurements of serum amylase activity confirmed a rising trend, reaching as high as 5791 U/l. Abdominal ultrasound examination did not reveal any abnormality, although the pelvic region was not examined.
, 百拇医药
Over subsequent weeks the patient was labelled variously as having "known chronic pancreatitis" and "recurrent pancreatitis" on account of her persistent hyperamylasaemia, even though at no time did she complain of abdominal pain. A pancreatic pseudocyst was considered, but computed tomography of the abdomen did not show any pancreatic abnormality. (It did, however, reveal a large lobulated pelvic mass, thought to be consistent with a fibroid uterus.) Macroamylasaemia, when amylase combines with plasma proteins to form complexes that cause artefactual hyperamylasaemia, was also excluded (see below). Renal function was normal throughout. Pancreatic lipase activity was 22 U/l (reference interval 22-51 U/l), making it unlikely that the raised amylase activity was coming from the pancreas and prompting the search for an alternative tissue source.
, 百拇医药
The patient then developed extensive deep vein thrombosis in the right femoro-iliac veins. Doppler ultrasonography raised the possibility of an ovarian neoplasm, and repeat computed tomography of the abdomen confirmed the presence of a complex pelvic mass (and the absence of a pancreatic lesion). The possibility of an ovarian neoplasm as the source of amylase was considered and explored. The patient underwent salpingo-oophorectomy.
Histological examination of the tissue confirmed the mass to be a malignant neoplasm composed of pleomorphic cells with a solid architecture. The tumour was thought to represent a poorly differentiated ovarian endometroid adenocarcinoma. Subsequent immunohistochemical staining with an antibody against amylase showed positive brown-black immunoperoxidase staining of the tumour cells, implicating the ovarian tumour as the source of amylase production (fig 1).
, http://www.100md.com
By the third postoperative day, the patient's amylase activity had fallen to 247 U/l (from a preoperative concentration of 5791 U/l), and then to 47 U/l by the end of the third postoperative week (fig 2). The patient received chemotherapy postoperatively. Computed tomography of the abdomen and pelvis seven months later showed no evidence of tumour recurrence. One year later, the patient's amylase activity is 84 U/l. Clinically she is well.
Discussion
, 百拇医药
A raised serum amylase activity is found in several different clinical contexts. In patients presenting with acute abdominal pain, acute pancreatitis is the most likely diagnosis, especially if amylase activity is markedly raised (> 10 times the upper limit of normal). Causes of more modest elevation include ruptured tubal pregnancy, perforated hollow viscus, small bowel obstruction, generalised peritonitis, diabetic ketoacidosis, and the administration of opiates (which cause spasm of Oddi's sphincter). A different clinical scenario exists when the salivary glands are inflamed, most often with calculi or mumps; the resultant hyperamylasaemia is not usually a diagnostic problem.
, http://www.100md.com
Asymptomatic hyperamylasaemia has several causes. Pancreatic pseudocysts may form during or after episodes of acute pancreatic necrosis. The amylase activity within these pseudocysts may be extremely high, and leakage into the blood may be associated with marked hyperamylasaemia. Sometimes amylase molecules combine with plasma proteins (usually immunoglobulins). The resultant complexes are so large that they can be precipitated by certain agents (such as polyethylene glycol) and cannot be cleared by the kidneys—in contrast with amylase, which has a relatively low molecular mass, doesn't precipitate (much), and is readily excreted except in renal failure. Macroamylase is a well recognised phenomenon, at least by laboratory staff, and if suspected can be readily confirmed or excluded.1 In this patient, very high amylase activity was seen in urine (12 218 U/l), and only 9% of amylase activity precipitated (reference interval < 57%), thus excluding macroamylasaemia.
, 百拇医药
Production of amylase (usually the salivary isoenzyme) has been documented with various kinds of ovarian neoplasm. Serous cystadenocarcinoma, mucinous tumour, surface papillary carcinoma, and endometrial adenocarcinoma of the ovary have all been implicated.2-5 Other malignancies reported to secrete amylase include gastric carcinoma, multiple myeloma, lung carcinoma, and phaeochromocytoma.6-9 The basis of amylase production by malignant tissue is unclear, although its secretion by tissues known to contain amylase might be activated through pathological processes such as inflammation or tumour formation.10
, 百拇医药
Interpreting hyperamylasaemia is not always straightforward, and results of investigations must be interpreted in the light of clinical findings
Contributors: All authors participated in preparing the manuscript and approved the final version. LAJ also participated in the histopathological analysis of the tumour tissue sample. MJM is guarantor for the report.
Competing interests: None declared.
, 百拇医药 References
Boyle CE, Fraser CG. Macroamylasaemia: how common is it BMJ 1985;291: 1389.
Tanaka Y, Ueda G, Tanizawa O, Miyake H, Kohno M, Nishiyama S, et al. A case of amylase-producing ovarian tumour [in Japanese]. Gan No Rinsho 1986;32: 111-6.
Griffin NR, Wells M. Immunolocalization of alpha-amylase in ovarian mucinous tumours. Int J Gynecol Pathol 1990;9: 41-6.
, 百拇医药 O'Riordan T, Gaffney E, Tormey V, Daly P. Hyperamylasemia associated with progression of a serous surface papillary carcinoma. Gynecol Oncol 1990;36: 432-4.
Juang CM, Yeng MS, Twu NF, Chao GC. Hyperamylasemia associated with endometroid carcinoma of the ovary. Zhonghua Yi Xue Za Zhi (Taipei) 2000;63: 710-3.
Kosches DS, Sosnowik D, Lendvai S, Bank S. Unusual anodic migrating isoamylase differentiates selected malignant from nonmalignant ascites. J Clin Gastroenterol 1989;11: 43-6.
, 百拇医药
Ross CM, Devgun MS, Gunn IR. Hyperamylasaemia and multiple myeloma. Ann Clin Biochem 2002;39(Pt 6): 616-20.
Nakao M, Kodama T, Sasaki M, Kuroda K. A case of ectopic amylase-producing lung cancer [in Japanese]. Kyobu Geka 1996;49: 1069-77.
Perrier NA, van Heerden JA, Wilson DJ, Warner MA. Malignant pheochromocytoma masquerading as acute pancreatitis—a rare but potentially lethal occurrence. Mayo Clin Proc 1994;69: 366-70.
Maeda M, Otsuki M, Yuu H, Saeki S, Yamasaki T, Baba S. Salivary-type hyperamylasemia in primary lung cancer: observation of a possible precursor of the salivary-type amylase. Eur J Cancer Clin Oncol 1982;18: 123-8., 百拇医药(Rajeev Srivastava, Callum)
Introduction
Interpretation of abnormally high serum amylase activity is not always straightforward. Sometimes, as here, patients are erroneously labelled as having pancreatitis despite the absence of clinical features to support this diagnosis. Such assumptions may affect the interpretation of investigations.
, 百拇医药
Case report
A 53 year old woman was admitted to hospital, initially with a dense hemiparesis and dysarthria because of a left middle cerebral infarct. At the time of admission, she was recovering from a recent myocardial infarction. She was not known to be diabetic.
About six weeks after admission she complained of several episodes of vomiting. Routine haematology and biochemistry investigations were unremarkable apart from serum amylase activity of 1730 U/l (reference interval 0-100 U/l). This result immediately prompted surgical review. The surgical senior house officer diagnosed acute pancreatitis. A few days later the surgical registrar confirmed this clinical impression, although, in the complete absence of abdominal pain, the pancreatitis was described as mild. Multiple repeated measurements of serum amylase activity confirmed a rising trend, reaching as high as 5791 U/l. Abdominal ultrasound examination did not reveal any abnormality, although the pelvic region was not examined.
, 百拇医药
Over subsequent weeks the patient was labelled variously as having "known chronic pancreatitis" and "recurrent pancreatitis" on account of her persistent hyperamylasaemia, even though at no time did she complain of abdominal pain. A pancreatic pseudocyst was considered, but computed tomography of the abdomen did not show any pancreatic abnormality. (It did, however, reveal a large lobulated pelvic mass, thought to be consistent with a fibroid uterus.) Macroamylasaemia, when amylase combines with plasma proteins to form complexes that cause artefactual hyperamylasaemia, was also excluded (see below). Renal function was normal throughout. Pancreatic lipase activity was 22 U/l (reference interval 22-51 U/l), making it unlikely that the raised amylase activity was coming from the pancreas and prompting the search for an alternative tissue source.
, 百拇医药
The patient then developed extensive deep vein thrombosis in the right femoro-iliac veins. Doppler ultrasonography raised the possibility of an ovarian neoplasm, and repeat computed tomography of the abdomen confirmed the presence of a complex pelvic mass (and the absence of a pancreatic lesion). The possibility of an ovarian neoplasm as the source of amylase was considered and explored. The patient underwent salpingo-oophorectomy.
Histological examination of the tissue confirmed the mass to be a malignant neoplasm composed of pleomorphic cells with a solid architecture. The tumour was thought to represent a poorly differentiated ovarian endometroid adenocarcinoma. Subsequent immunohistochemical staining with an antibody against amylase showed positive brown-black immunoperoxidase staining of the tumour cells, implicating the ovarian tumour as the source of amylase production (fig 1).
, http://www.100md.com
By the third postoperative day, the patient's amylase activity had fallen to 247 U/l (from a preoperative concentration of 5791 U/l), and then to 47 U/l by the end of the third postoperative week (fig 2). The patient received chemotherapy postoperatively. Computed tomography of the abdomen and pelvis seven months later showed no evidence of tumour recurrence. One year later, the patient's amylase activity is 84 U/l. Clinically she is well.
Discussion
, 百拇医药
A raised serum amylase activity is found in several different clinical contexts. In patients presenting with acute abdominal pain, acute pancreatitis is the most likely diagnosis, especially if amylase activity is markedly raised (> 10 times the upper limit of normal). Causes of more modest elevation include ruptured tubal pregnancy, perforated hollow viscus, small bowel obstruction, generalised peritonitis, diabetic ketoacidosis, and the administration of opiates (which cause spasm of Oddi's sphincter). A different clinical scenario exists when the salivary glands are inflamed, most often with calculi or mumps; the resultant hyperamylasaemia is not usually a diagnostic problem.
, http://www.100md.com
Asymptomatic hyperamylasaemia has several causes. Pancreatic pseudocysts may form during or after episodes of acute pancreatic necrosis. The amylase activity within these pseudocysts may be extremely high, and leakage into the blood may be associated with marked hyperamylasaemia. Sometimes amylase molecules combine with plasma proteins (usually immunoglobulins). The resultant complexes are so large that they can be precipitated by certain agents (such as polyethylene glycol) and cannot be cleared by the kidneys—in contrast with amylase, which has a relatively low molecular mass, doesn't precipitate (much), and is readily excreted except in renal failure. Macroamylase is a well recognised phenomenon, at least by laboratory staff, and if suspected can be readily confirmed or excluded.1 In this patient, very high amylase activity was seen in urine (12 218 U/l), and only 9% of amylase activity precipitated (reference interval < 57%), thus excluding macroamylasaemia.
, 百拇医药
Production of amylase (usually the salivary isoenzyme) has been documented with various kinds of ovarian neoplasm. Serous cystadenocarcinoma, mucinous tumour, surface papillary carcinoma, and endometrial adenocarcinoma of the ovary have all been implicated.2-5 Other malignancies reported to secrete amylase include gastric carcinoma, multiple myeloma, lung carcinoma, and phaeochromocytoma.6-9 The basis of amylase production by malignant tissue is unclear, although its secretion by tissues known to contain amylase might be activated through pathological processes such as inflammation or tumour formation.10
, 百拇医药
Interpreting hyperamylasaemia is not always straightforward, and results of investigations must be interpreted in the light of clinical findings
Contributors: All authors participated in preparing the manuscript and approved the final version. LAJ also participated in the histopathological analysis of the tumour tissue sample. MJM is guarantor for the report.
Competing interests: None declared.
, 百拇医药 References
Boyle CE, Fraser CG. Macroamylasaemia: how common is it BMJ 1985;291: 1389.
Tanaka Y, Ueda G, Tanizawa O, Miyake H, Kohno M, Nishiyama S, et al. A case of amylase-producing ovarian tumour [in Japanese]. Gan No Rinsho 1986;32: 111-6.
Griffin NR, Wells M. Immunolocalization of alpha-amylase in ovarian mucinous tumours. Int J Gynecol Pathol 1990;9: 41-6.
, 百拇医药 O'Riordan T, Gaffney E, Tormey V, Daly P. Hyperamylasemia associated with progression of a serous surface papillary carcinoma. Gynecol Oncol 1990;36: 432-4.
Juang CM, Yeng MS, Twu NF, Chao GC. Hyperamylasemia associated with endometroid carcinoma of the ovary. Zhonghua Yi Xue Za Zhi (Taipei) 2000;63: 710-3.
Kosches DS, Sosnowik D, Lendvai S, Bank S. Unusual anodic migrating isoamylase differentiates selected malignant from nonmalignant ascites. J Clin Gastroenterol 1989;11: 43-6.
, 百拇医药
Ross CM, Devgun MS, Gunn IR. Hyperamylasaemia and multiple myeloma. Ann Clin Biochem 2002;39(Pt 6): 616-20.
Nakao M, Kodama T, Sasaki M, Kuroda K. A case of ectopic amylase-producing lung cancer [in Japanese]. Kyobu Geka 1996;49: 1069-77.
Perrier NA, van Heerden JA, Wilson DJ, Warner MA. Malignant pheochromocytoma masquerading as acute pancreatitis—a rare but potentially lethal occurrence. Mayo Clin Proc 1994;69: 366-70.
Maeda M, Otsuki M, Yuu H, Saeki S, Yamasaki T, Baba S. Salivary-type hyperamylasemia in primary lung cancer: observation of a possible precursor of the salivary-type amylase. Eur J Cancer Clin Oncol 1982;18: 123-8., 百拇医药(Rajeev Srivastava, Callum)