An Approach to the Abdominal Mass
Doctor, I feel a lump in my abdomen ! An Approach to the Abdominal Mass
Introduction
Clinical Examination
Differential Diagnosis
Evaluation Priorities
Context: OPD / Casualty
Introduction
Some patients present with an abdominal lump. Given the thickness of the abdominal wall and musculature, this finding is often unclear, and sometimes it is not born out by your clinical examination.
If real, it often is a sign of serious pathology that has major consequences for the patient.
Like all masses, you need to ask the usual “lump related” questions:
Where is it ? | The clinical implications and differential diagnosis are very different depending on where it is ! |
When and how did you first notice the lump? | Was it noticed incidentally, or did related symptoms point it out ? When was it first noticed ? |
How has the lump changed since you first noticed it ? | Has it got bigger, smaller, stayed the same size or has it come and gone ? Has it changed its appearance and consistency ? |
What symptoms does it cause you ? | Is it painful ? Does it cause any other symptoms ? The key is to interrogate the GIT, and urogenital systems. |
Have you got any more / had it before ? | If the patient has many lumps, are they the same ? If the patient has had this before, what happened to it the last time, and what did the doctor say it was ? |
What do you think it is ? | Most patients worry that this could be cancer. You have to aware of the patient’s concerns if you want to be able to reassure them |
There is no substitute for a sound approach and thorough clinical evaluation of such cases. You have to take time, ask a comprehensive set of questions about the presenting symptoms, associated complaints, and a systematic enquiry. Always examine the patient properly. Do not throw your hands up in the air, and “just do bloods and order a CT” ; apply your mind and MAKE A CLINICAL DIAGNOSIS !
Be inquisitive, and take pride in the clinical assessment of each case.
ASK ABOUT PAIN THOROUGHLY : define the presenting complaint
Pain | |
Location and Radiation | Where is it, and where does it radiate to ? RUQ - liver or biliary tree Shoulder tip - diaphragmatic irritation Back - retroperitoneal pathology Groin - renal or iliopsoas disease RIF - appendix / ileocaecal disease LIF - colon |
Temporal Elements | The onset, frequency, and duration of the pain are helpful features Neoplasms = gradual and persistent Perforation with localized abscess = sudden onset & high intensity |
Severity | The severity of the pain generally is related to the severity of the disorder, especially if acute in onset High intensity = advanced malignancy / abscess |
Precipitants or Ameliorating Factors | Identify what precipitates or improves the pain Pancreatitis = strong association with alcohol intoxication |
| Other Symptoms | |
GIT Symptoms | Nausea, vomiting = Gastric Outlet Obstruction due to Gastric Cancer ? Constipation = Colorectal Malignancy Jaundice = HPB malignancy or Chronic Pancreatitis |
Genitourinary Symptoms | Hematuria = renal cell carcinoma |
Gynaecological History | Menstrual history (LMP, previous period, cycle length) – make sure the patient is NOT PREGNANT Dyspareunia or Dysmenorrhea - possible Uterine or Ovarian Neoplasms |
Constitutional Symptoms | Fevers, rigors = Peritonitis, UTI, Cholangitis Fatigue, Weight loss, and Anorexia = Malignancy, TB, Systemic Illnesses, Inflammatory Bowel Disease |
TAKE A COMPREHENSIVE HISTORY : this allows you to consider other causes, and contextualise the
patient’s fitness for intervention
Cardio - Respiratory Symptoms | Does the patient have co-morbidities ? Cough, Shortness of Breath, Orthopnea, Exertional Dyspnea, Angina Consider AAA in patients with CVS co-morbidity |
Past Medical History | Previous Abdominal Surgery = ? Bowel Obstruction or recurrent Cancer Recent Trauma = ? Traumatic Pancreatitis & Pseudocyst HIV +ve = Abdominal Tuberculosis Previous Malignancy = Cancer recurrence / obstruction ? |
Precipitants & other Aetiological Factors | Alcohol = Acute or Chronic Pancreatitis ? Recent blunt or penetrating trauma = Delayed Bowel Perforation, Pancreatitis, Diaphragmatic Herniae, Liver Haematoma, False Aneurysm |
Clinical Examination
General Examination | Pyrexia = Peritonitis, TB, UTI, PID Anaemia = Malignancy , Chronic Disorders, AAA Jaundice = Biliary Obstruction Peripheral Adenopathy = Malignancy |
Abdominal Examination | Inspect - for Scars, Herniae, Masses, Distention (examine the Groins & Scrotum- remember to exclude Testicular Tumours!) Percuss - Tympany = Distended Bowel Dullness = Mass/ Organomegaly Shifting dullness = Ascites Palpation - Examine all abdominal sites BEFORE feeling the alleged mass. Decide if you can “really” feel it or if it just a vague impression. If you can feel it, decide if you think it is easily mobile or fixed ? These are good proxies for “resectability”. Define size, shape, consistency, tenderness, mobility, pulsation Auscultation - Bruit or murmur = AAA, Renal Artery Aneurysm |
Rectal and Pelvic Examination | Patients with an abdominal mass must have a rectal examination. Stool bolus = Fecal Impaction & Obstruction in older adults Tender PR = Pelvic Abscess Blood PR = Colorectal Malignancy All women must have a pelvic examination Is there a Uterine or Ovarian Mass? |
Differential Diagnosis
There are multiple diagnoses to consider, and unless you use a structured approach the clinical scenarios can feel overwhelming.
It is practical to consider a diagnostic algorithm that starts with a broad range of conditions and narrows down to the ones most pertinent to a surgical unit.
An old fashioned but helpful pneumonic is : “remember the 6 F’s” : some of these are easily excluded after a clinical examination.
Causes of an abdominal mass | Fat Foetus Fibroids Fluid (ascites or urine) Flatus Faeces Fatal Tumour |
To be more comprehensive to differentiate the various causes of an abdominal mass, decide on which quadrant the mass is & consider the anatomical structures in that region.
Right Upper Quadrant Mass | |
Common Causes | Clinical features |
Liver mass | Many possible pathologies - commonest are an Amoebic Abscess or Liver Tumours. |
Palpable Gallbladder | If painless & obstructive jaundice = Courvoiser’s law = ? HPB malignancy If fever + RUQ pain = ? Gall Bladder Empyema |
Rare causes | Adrenal Neoplasm / Renal Neoplasm / Advanced Colonic Neoplasm |
| Epigastric & Central Abdominal Mass | |
Common Causes | Clinical features |
Pancreatitis Pseudocyst | Either as a complication of severe acute pancreatitis or in chronic pancreatitis, associated with persistent upper abdominal pain radiating to the back. |
Gastric Mass | Either advanced gastric carcinoma or GIST. |
AAA | Pulsatile central mass |
Rare causes | Pancreatic Malignancy / Retroperitoneal Adenopathy / Retroperitoneal Sarcoma / Paraganglioma |
Left Upper Quadrant Mass This is the least common location ; the aetiology overlaps significantly with the common causes of an epigastric mass | |
Rarer causes | Clinical features |
Splenomegaly | Associated with a variety of underlying conditions (eg, hypercoagulable state, atrial fibrillation, and splenomegaly). Commonly presents with pain radiating to the tip of the shoulder, and sympathetic pleural effusion |
| Splenic Abscess | Associated with fever and LUQ tenderness may be a complication of splenic infarction. |
Lower Abdominal Mass | |
Common Causes | Clinical features |
Appendix Abscess | Right lower quadrant pain, Anorexia, Nausea, and Vomiting. Low-grade Pyrexia and Localised Peritonism. |
Diverticulitis | Older patient. Pain usually constant in the left iliac fossa, and present for several days prior to presentation. May have associated nausea and vomiting. |
Ovarian Neoplasm | Often painless. No GI symptoms |
Colon Carcinoma | Change of bowel habit, Anaemia |
Rare causes | Crohn's disease, TB Enteritis, Endometriosis, Iliopsoas Abscess, Intussusception |
At any site, remember that masses can also arise from the abdominal wall :
Abdominal Wall Mass | |
Common Causes | Clinical features |
Incarcerated hernia | Characteristic site (Umbilical/ Epigastric/ Groin) or at the site of previous surgery. |
Rare causes | Abdominal Wall Abscess, Rectus Sheath Haematoma, Desmoid Tumour, Sarcoma |
Evaluation Priorities
What is the diagnosis?
Do baseline tests and plain imaging
Check urine, pregnancy test, CXR, U&E, LFT, lipase, tumour markers
You will almost always order some form of cross-sectional abdominal imaging to confirm your clinical findings, and/or to reassure the patient if you are uncertain.
Commonly used investigations
Test | Ideal context | Issues to consider |
US | Thin patient, good in biliary and gynae pathology | Operator dependent, but widely available and relatively cheap |
CT | Best for obese patients, or suspected retroperitoneal or pancreatic pathology | By far the best investigation but it is expensive, uses IV contrast, and is not always available |
MRI | Adds extra information in some pancreatic or liver cases | Very expensive, least availability |
What other investigations must I consider?
With a solid lesion, it is important to obtain tissue for histological diagnosis. This is usually achieved by a US or CT guided core biopsy.
Bear in mind that some lesions should NOT be biopsied: resectable liver tumours, highly vascular lesions, functional paragangliomas. To be sure, always discuss the decision to biopsy with senior surgeons and radiologists.
If the imaging suggests an abscess, the next step is usually percutaneous drainage.
The investigations below are occasionally helpful, and their role is strongly guided by the original CT or US report.
Test | Ideal context | Issues to consider |
Contrast study | Can demonstrate obstructions or tumours arising from the GIT, especially from the oesophagus and stomach | Largely replaced by CT scans with either oral or rectal contrast. |
Endoscopy | If suspecting a gastric or colonic neoplasm | Widely available allows for histological diagnosis |
Laparoscopy | Excellent to differentiate TB or metastatic disease | Commits patient to surgery uses theatre resources, requires surgical expertise |
Angiography | Vascular cases with occult bleeding or false aneurysm | Requires very specific endovascular skills |
SHOULD I OPERATE OR NOT ?
The decision to intervene surgically is the most significant of all the issues and must be made only after all the investigations are complete and a confident diagnosis is made.
It is extremely unusual for any of the causes of an abdominal mass to require immediate surgery (with the exception of a leaking aortic aneurysm, or even less common vascular problems).
Resist the temptation to perform a laparotomy to “just have a look”.
An intra-abdominal mass procedure needs senior presence and decision making. It is almost always a major “elective” operation.