Abdominal Wall Mass

• • Myriad of conditions manifest clinically with a palpable abdominal wall mass

  • Key to diagnosis is careful history and physical exam

  • Asymptomatic deep abdominal wall mass may be incidentally discovered on imaging studies

Epidemiology

• • Rectus hematomas may arise following abdominal wall trauma or occur spontaneously in patients receiving anticoagulant therapy

  • Spontaneous abdominal wall metastases are most commonly associated with lung and pancreatic adenocarcinoma

  • Any intra-abdominal malignancy can extend into the abdominal wall or secondarily seed laparotomy incisions

Symptoms and Signs

• • Rectus hematoma: An exquisitely tender mass that becomes more painful with flexion of the abdominal wall with surrounding ecchymosis is the classic finding

  • Deep wound infection or abdominal wall abscess: Signs of infection or inflammation (erythema, induration, tenderness, exudate)

  • Abdominal wall hernia: A reducible bulge that develops with the Valsalva maneuver

  • Soft-tissue neoplasms: Most are asymptomatic with a slow growth pattern

Laboratory Findings

• • Coagulopathy may be present in patients with rectus sheath hematoma

  • Leukocytosis with deep wound infection or abdominal wall abscess

Imaging Findings

• • Plain abdominal films are usually normal

  • US can differentiate between a solid and a fluid-filled mass and reliably demonstrate the presence of abdominal viscera in the case of an incarcerated abdominal wall hernia

  • CT will characterize the mass and differentiate between hematoma, fat, soft-tissue, and fluid-density lesions

  • MRI is best method to evaluate soft-tissue masses suspicious for sarcoma

• • Rectus hematoma

  • Tumor metastasis

  • Desmoid tumor

  • Deep wound infection

  • Abdominal wall abscess

  • Soft-tissue sarcoma

  • Incisional hernia

  • Interparietal hernia

  • Spigelian hernia

  • Lipoma

  • Hemangioma

  • Fibroma

  • Endometrioma

  • Stitch abscess

  • Stitch granuloma

Rule Out

• • Tumor metastasis

  • Hernia

  • Soft-tissue sarcoma

• • Careful history

  • -Malignancy (metastasis)

    -Constitutional symptoms (metastasis)

    -Trauma (hematoma)

    -Cesarean section (desmoid tumor, endometrioma)

    -Familial adenomatous polyposis (desmoid tumor)

    -Prior laparotomy (incisional hernia)

    -Fever and chills (deep wound infection or abdominal wall abscess)

  • Careful physical exam

  • -Mass reducible (hernia)

    -Mass expanding (hematoma)

    -Pain, erythema, and induration (deep wound infection or abdominal wall abscess)

  • Obtain CT or MRI when solid mass is suspicious for abdominal wall metastasis, soft-tissue sarcoma, or desmoid tumor

  • Perform percutaneous biopsy for solid mass

When to Admit

• • Uncomplicated abdominal wall mass work-up may be performed as an outpatient

  • Patients with deep wound infection or abdominal wall abscess need to be admitted for drainage and antibiotic therapy

  • Patients with complicated hernia (incarcerated, strangulated, small bowel obstruction) require admission for urgent surgical treatment

• • Rectus sheath hematoma: Correct coagulopathy, avoid antiplatelet medications, control pain, and provide expectant management

  • Soft-tissue mass: Radiographic characterization with percutaneous or incisional biopsy to establish the diagnosis ...