What is the appropriate management for a 35-week pregnant female with sharp and intermittent pain at a previous incision site, sometimes constant, and a hard lump on palpation?

Management of Incisional Pain and Hard Lump at 35 Weeks Gestation

Perform ultrasound of the incision site immediately to differentiate between seroma, hematoma, abscess, or wound dehiscence, as this will guide definitive management and prevent progression to serious complications.

Initial Diagnostic Approach

The presentation of sharp, intermittent-to-constant pain with a palpable hard lump at a previous incision site in a 35-week pregnant patient requires urgent imaging evaluation to establish the diagnosis:

• Ultrasound is the first-line imaging modality for evaluating incisional complications during pregnancy, as it avoids radiation exposure and can effectively characterize fluid collections, masses, and tissue integrity 1.
• The hard lump most likely represents one of the following: seroma (sterile fluid collection), hematoma (blood collection), abscess (infected fluid collection), or wound dehiscence with tissue separation 2.
• Key ultrasound findings to assess include presence of fluid collection, echogenicity of contents, vascularity, size of collection, and integrity of fascial layers 1.

Differential Diagnosis Based on Clinical Features

Sterile Seroma

• Characteristics: Fluctuant swelling, minimal erythema, no systemic signs (fever, tachycardia), absence of purulent drainage 2.
• Pain may be present due to tissue tension but is typically less severe than with infection.

Surgical Site Infection (SSI)

• Characteristics: Purulent drainage, significant pain and tenderness, erythema extending >5 cm from wound edge, induration, fever >38.5°C, or tachycardia >110 bpm 2.
• Requires immediate intervention to prevent systemic sepsis.

Hematoma

• Presents as firm, tender mass with possible ecchymosis.
• May expand if active bleeding continues 1, 3.

Wound Dehiscence

• Separation of incision layers, which may occur with or without infection 2.
• Can progress to complete fascial disruption if not addressed.

Management Algorithm

If Sterile Seroma is Confirmed

• Prompt drainage is the cornerstone of treatment, followed by wound care with dressing changes to promote healing by secondary intention 2.
• Do NOT use prophylactic antibiotics for sterile seromas, as this promotes antibiotic resistance without clinical benefit 2.
• Consider negative pressure wound therapy (NPWT) for recurrent or large seromas (>3 cm depth), which promotes granulation tissue formation and obliterates dead space, with significant reduction in SSI (pooled OR 0.25; 95% CI 0.12-0.52) 2.

If Surgical Site Infection is Confirmed

• Drain any fluid collections immediately and open the wound as needed to establish adequate drainage 2.
• Initiate antibiotic therapy covering mixed gram-positive, gram-negative, and anaerobic flora: ampicillin-sulbactam, cefoxitin, or ertapenem 4.
• Continue antibiotics until systemic signs resolve and wound shows improvement 2.
• Do NOT place subcutaneous drains prophylactically in already dehisced wounds, as drainage is achieved by opening the incision 2.

If Hematoma is Present

• Small hematomas (<4 cm) may be managed conservatively with observation 1, 3.
• Larger hematomas (>5 cm) require drainage and evaluation for ongoing bleeding source 1.
• If expanding or associated with hemodynamic instability, consider CT with IV contrast to identify active extravasation and surgical re-exploration 3.

If Wound Dehiscence is Identified

• Immediate surgical consultation is required to assess extent of fascial separation 2, 4.
• Superficial dehiscence may be managed with wound care and secondary intention healing.
• Deep fascial dehiscence requires surgical repair with interrupted absorbable sutures 4.

Monitoring and Follow-Up

• Evaluate wound healing progress at regular intervals (every 2-3 days initially) 2.
• Watch for development of infection signs if initially presenting as sterile seroma, as secondary infection can occur 2.
• Serial ultrasound may be needed if clinical deterioration occurs or mass enlarges 1.
• Maintain low threshold for repeat imaging if pain worsens, fever develops, or mass increases in size 3.

Critical Pitfalls to Avoid

• Never delay imaging in a pregnant patient with incisional pain and mass, as ultrasound is safe and provides critical diagnostic information 1.
• Avoid empiric antibiotics without confirming infection, as sterile seromas do not benefit from antimicrobial therapy 2.
• Do not assume all incisional masses are benign in pregnancy—while rare, pregnancy-associated complications like cesarean scar pregnancy or abdominal pregnancy can present with incisional pain if prior surgery was in the area 5, 6.
• Recognize that small collections can rapidly expand—maintain high clinical suspicion and repeat imaging if clinical deterioration occurs 3.