What is the proper management for a patient with a 14 cm mass at the site of a previous right hemicolectomy (surgical removal of the right side of the colon) for familial polyposis coli (FPC) 10 years ago?

Management of 14 cm Mass at Previous Right Hemicolectomy Site in FAP Patient

The proper management is wide local excision (Option C), as this 14 cm mass at the operation site 10 years post-hemicolectomy for familial polyposis coli is most consistent with a desmoid tumor, which requires surgical resection when feasible, particularly for large, symptomatic, or strategically located lesions. 1

Clinical Reasoning

Most Likely Diagnosis: Desmoid Tumor

• Desmoid tumors occur in 10-15% of FAP patients and represent a major cause of morbidity and mortality after colectomy 1, 2
• The presentation of a large mass at a previous surgical site in an FAP patient is pathognomonic for desmoid tumor, as these lesions characteristically develop at sites of prior abdominal surgery 1, 3, 2
• Desmoid tumors are locally aggressive fibroblastic proliferations that do not metastasize but can cause life-threatening complications through local invasion and impingement on vital structures 1, 3
• The 10-year interval since surgery is consistent with desmoid tumor development, which can occur years after the initial operation 4, 2

Why Surgical Excision is Appropriate

For extra-abdominal and abdominal wall desmoids of this size (14 cm), surgical excision remains the primary treatment option when technically feasible 1:

• The British Society of Gastroenterology (2020) guidelines recommend restricting elective surgery for intra-abdominal desmoids to treating secondary effects, but this applies primarily to mesenteric desmoids 1
• Abdominal wall desmoids (which occur at surgical sites) have better surgical outcomes with lower recurrence rates compared to intra-abdominal mesenteric desmoids 1, 5
• Wide local excision with adequate margins is the standard surgical approach, though microscopic margin status does not significantly affect recurrence rates 5, 4
• Historical data shows 89% survival and 84-88% disease-free status after surgical resection of desmoid tumors 4

Why Other Options Are Inappropriate

Conservative management (Option B) is not appropriate for a 14 cm lesion:

• While watchful waiting has emerged as initial management for some desmoid tumors, this applies primarily to smaller, asymptomatic lesions 5
• A 14 cm mass is too large for observation alone and likely causing symptoms or at high risk for complications 3
• Only 58% of patients succeed with watchful waiting alone, and progression occurs in 42% with median progression-free survival of only 10 months 5

Medical therapy (sulindac + selective estrogen receptor modulators) has limited efficacy:

• The BSG guidelines suggest this combination may be effective for FAP-associated desmoids, but evidence quality is low 1
• Medical therapy is more appropriate as adjuvant treatment or for inoperable lesions, not as primary management for large, resectable tumors 1

Combined chemoradiotherapy (Option D) is not indicated:

• Desmoid tumors are benign lesions that do not respond to traditional chemotherapy regimens used for malignancies 3, 2
• Radiation therapy may be used as adjuvant treatment after incomplete resection or for unresectable lesions, but not as primary treatment 4

Triple chemotherapy (Option A) has no role:

• This would only be appropriate for metastatic colorectal cancer, which is not the clinical scenario here 1
• The 10-year interval and location at the surgical site make recurrent colorectal cancer extremely unlikely 1

Surgical Approach and Considerations

The surgical procedure should be performed at an expert center with experience in complex abdominal wall reconstruction 1:

• Full-thickness abdominal wall excision may be required for adequate margins 3
• Reconstruction with mesh and possible flap coverage should be planned for large defects 3
• Staged procedures may be necessary for very large tumors (as demonstrated in a case of 40 cm desmoid requiring two-stage reconstruction) 3

Important Caveats

• Recurrence rates after surgery range from 15-20%, but this is still superior to progression rates with observation alone 5, 4
• Positive microscopic margins do not significantly increase recurrence risk (14% vs 20%, p=1.0), so aggressive pursuit of negative margins at the expense of vital structures is not warranted 5
• Postoperative complications can be significant, particularly for large resections requiring complex reconstruction 3
• Multidisciplinary evaluation should include assessment for intra-abdominal extension that might complicate surgical planning 1