Is the chest CT report likely erroneous in labeling the abdominal findings as lymphangitic carcinomatosis instead of the known peritoneal carcinomatosis, and what are the appropriate next steps?

Likely Radiology Report Error and Recommended Next Steps

This is almost certainly a reporting error—the radiologist likely confused "lymphangitic carcinomatosis" with "peritoneal carcinomatosis" when describing the abdominal findings of ascites and peritoneal thickening. Lymphangitic carcinomatosis refers specifically to tumor spread through pulmonary lymphatics, not peritoneal disease, and the chest CT explicitly states there is no evidence of lung or nodal metastases 1.

Understanding the Terminology Error

Pulmonary lymphangitic carcinomatosis is characterized by thickening of bronchovascular bundles and interlobular septa due to proliferation of neoplastic cells within pulmonary lymphatics 1. The radiographic features include:

• Linear or reticulonodular lesions on chest radiographs
• Ground-glass opacities and septal thickening (smooth or nodular) on CT
• Bilateral asymmetric or unilateral distribution 1

The findings described in your report—"small volume ascites and peritoneal thickening"—are classic manifestations of peritoneal carcinomatosis, not lymphangitic carcinomatosis 1. These are entirely different disease processes affecting different anatomic compartments.

Why This Matters Clinically

Lymphangitic carcinomatosis carries an extremely poor prognosis with median survival of only 2-7 months in most cases 2. If this diagnosis were accurate, it would represent:

• Progressive pulmonary metastatic disease
• A contraindication to many surgical interventions
• A fundamental change in treatment approach and prognosis 2, 3

However, since the chest CT explicitly documents "no evidence of a primary lung malignancy nor metastatic lung or nodal disease," the patient does NOT have pulmonary lymphangitic carcinomatosis 1.

Immediate Recommended Actions

1. Contact the Interpreting Radiologist Directly

• Request immediate clarification or formal addendum to the report 4
• Specifically ask whether they intended to describe "peritoneal carcinomatosis" rather than "lymphangitic carcinomatosis"
• Diagnostic errors in abdominopelvic CT interpretation occur in approximately 0.5% of reports, with missed findings and terminology errors being common reasons for addenda 4

2. Review the Actual CT Images

• Confirm that the lung parenchyma shows no septal thickening, ground-glass opacities, or reticulonodular patterns that would indicate true lymphangitic carcinomatosis 1
• Verify that the abdominal findings are limited to ascites and peritoneal thickening consistent with known peritoneal carcinomatosis
• The American College of Radiology emphasizes that CT provides superior tissue characterization and can definitively distinguish between different disease processes 1, 5

3. Obtain Formal Report Correction

• Request a formal addendum correcting the terminology from "lymphangitic carcinomatosis" to "peritoneal carcinomatosis" 4
• This is critical for accurate medical records, treatment planning, and prognostic discussions
• Comparison with prior imaging is one of the most common reasons for report modifications (30.6% of addenda) 4

Clinical Context Supporting This Being an Error

Peritoneal carcinomatosis can occur with various primary malignancies including gastric, breast, lung, and pancreatic cancers—the same primaries that cause lymphangitic carcinomatosis 1, 2. This overlap may have contributed to the terminology confusion.

True pulmonary lymphangitic carcinomatosis would show characteristic CT findings including thickening of bronchovascular bundles, septal thickening, and often mediastinal lymphadenopathy (present in 51.2% of cases) 1, 2. The absence of these findings on chest CT makes the diagnosis impossible.

Common Pitfall to Avoid

Do not assume this is simply alternative terminology or that "lymphangitic" and "peritoneal" carcinomatosis are interchangeable terms—they represent fundamentally different metastatic patterns with different prognoses and treatment implications 1, 2, 3. While rare case reports describe peritoneal mesothelioma causing pulmonary lymphangitic spread 6, this would require visible pulmonary changes on CT, which are explicitly absent in your patient.

The key distinguishing feature is anatomic location: lymphangitic carcinomatosis affects the lungs, while peritoneal carcinomatosis affects the peritoneal cavity 1. Your patient's findings are confined to the abdomen with normal lung parenchyma.