What are the potential causes and management options for an upper left abdominal mass?

Upper Left Abdominal Mass: Diagnostic and Management Approach

Immediate Assessment

Begin with rapid hemodynamic assessment checking for tachycardia, hypotension, fever, and peritoneal signs (guarding, rigidity, rebound tenderness) to identify perforation, rupture, or sepsis requiring emergency intervention. 1

• Evaluate for signs of shock, pallor, or acute distress 1
• Document vital signs including pulse, blood pressure, temperature, and respiratory rate 1
• Assess for abdominal distension, asymmetry, visible masses, and skin changes 1

Physical Examination Specifics

Characterize the mass by determining its exact location, size (measure dimensions), consistency, mobility, and presence of pulsatility—the latter suggesting vascular origin such as splenic artery aneurysm. 1

• Perform digital rectal examination to assess lower abdominal and pelvic extension 1
• Document extraintestinal manifestations: joint symptoms, skin changes, eye findings (suggesting inflammatory bowel disease), or lymphadenopathy (suggesting malignancy) 1
• In obese patients, measure waist circumference to distinguish true masses from adipose tissue 1

Common Upper Left Quadrant Etiologies

The differential diagnosis for upper left abdominal masses includes:

• Splenic pathology: Splenomegaly, splenic cysts, splenic abscess, or splenic tumors
• Gastric lesions: Gastrointestinal stromal tumors (GISTs), gastric carcinoids, lymphomas, or gastric carcinoma 2
• Pancreatic tail masses: Pancreatic neuroendocrine tumors or pancreatic adenocarcinoma 2
• Colonic pathology: Giant sigmoid diverticulum (rare but reported), splenic flexure tumors, or colorectal cancer 2, 3
• Retroperitoneal masses: Retroperitoneal sarcomas, which often present as large masses before symptoms develop 1, 4
• Renal masses: Left kidney tumors or hydronephrosis

Initial Imaging Strategy

Order abdominal ultrasound as the first-line imaging modality to determine if the mass is solid or cystic, assess vascularity, and identify organ of origin. 1, 5

• If ultrasound is indeterminate or suggests a complex mass, proceed immediately to contrast-enhanced CT scan of the abdomen and pelvis 5, 6
• CT provides superior characterization of retroperitoneal masses, pancreatic lesions, and relationship to surrounding structures 4, 6
• For gastric subepithelial masses, endoscopic ultrasound (EUS) is the most accurate test for determining the layer of origin and echogenicity 2

Tissue Diagnosis Approach

For masses ≥2 cm or those with concerning imaging features, obtain tissue diagnosis before definitive surgical planning to avoid inappropriate surgery for lymphomas, germ cell tumors, or benign conditions. 2, 4

For Gastric Masses:

• Masses <2 cm: EUS assessment with biopsy if feasible 2
• If biopsy inadequate or not feasible, active surveillance is acceptable with short-term reassessment at 3 months 2
• Masses ≥2 cm: Biopsy or excision required due to higher progression risk 2

For Retroperitoneal Masses:

• Image-guided core needle biopsy via retroperitoneal approach is mandatory before major resection, with <2% complication risk and <0.5% needle tract seeding risk. 4
• The biopsy pathway must avoid contamination of uninvolved compartments 4
• Biopsy is essential to exclude lymphoma or germ cell tumors requiring different treatment than sarcomas 4

For Suspected GISTs:

• Multiple core needle biopsies through EUS guidance or CT-guided percutaneous approach for large masses where multivisceral resection is anticipated 2
• This allows surgical planning, consideration of neoadjuvant treatment, and avoids surgery for conditions not requiring it 2

Management Based on Etiology

Gastrointestinal Stromal Tumors (GISTs):

• Resection is standard for GISTs ≥2 cm with local excision and clear margins; neither wide margins nor lymph node dissection are necessary. 2
• Laparoscopic or combined laparoscopic/endoscopic approaches have >90% success rates with shorter hospital stays 2
• For masses <2 cm with low-risk features, endoscopic resection is acceptable if complete excision without rupture is technically possible 2

Gastric Carcinoids:

• Type 1 and 2: Local excision adequate 2
• Type 3: Partial or total gastrectomy with lymph node dissection required due to aggressive behavior 2

Pancreatic Neuroendocrine Tumors:

• Major resection or wedge resection with node dissection 2
• Prophylactic octreotide should be available for interventional procedures 2

Colorectal Masses:

• Standard resection with locoregional lymphadenectomy 2
• At least 12 lymph nodes must be resected to avoid understaging 2
• For obstructing left-sided lesions, primary resection with or without anastomosis is preferred over stenting as bridge to surgery in most guidelines 2

Retroperitoneal Sarcomas:

• Immediate referral to specialized sarcoma center after biopsy confirmation, as adherence to evidence-based guidelines at expert centers improves survival. 4
• Multidisciplinary tumor board review determines need for neoadjuvant therapy before resection 4

Critical Pitfalls to Avoid

• Do not assume all pulsatile masses are vascular aneurysms—normal aortic pulsation can be prominent in thin patients. 1
• Do not skip plain abdominal radiography in acute presentations, as it can identify obstruction, perforation, or calcifications 1
• For suspected ovarian or gynecologic masses, avoid fine-needle aspiration due to risk of malignant cell spillage 5
• Do not perform surveillance on gastric masses ≥2 cm—these require tissue diagnosis or resection 2
• For rectal neuroendocrine tumors, biopsy or excision is required regardless of size, as progression risk is higher than gastric NETs 2

Emergency Situations Requiring Immediate Surgery

Proceed directly to laparoscopic or open exploration without delay for: hemodynamic instability, peritoneal signs suggesting perforation, pulsatile mass with rupture concern, or bowel obstruction. 1, 6

• For mobile abdominal masses not amenable to endoscopic assessment, laparoscopic/open excision is recommended 2
• Emergency presentations (suspected appendicitis, intestinal obstruction) require resections sufficient to correct the immediate problem, with consideration of more radical resection after definitive histopathology 2