Differential Diagnosis
- Single Most Likely Diagnosis
- Acute appendicitis: The findings of a mildly distended, fluid-filled appendix without surrounding inflammatory fat stranding are consistent with early or developing acute uncomplicated appendicitis.
- Probable infectious/inflammatory middle lobe nodule: The presence of a 9 mm noncalcified middle lobe nodule with surrounding ground-glass opacity suggests an infectious or inflammatory process, such as pneumonia.
- Other Likely Diagnoses
- Gastroenteritis: The presence of a fluid-filled appendix could also be seen in gastroenteritis, although the lack of surrounding inflammatory changes makes this less likely.
- Pulmonary granuloma: The middle lobe nodule could also represent a pulmonary granuloma, which could be caused by a variety of infectious or inflammatory processes.
- Do Not Miss Diagnoses
- Appendiceal rupture: Although the current findings do not show overt signs of rupture, such as free fluid or significant inflammatory changes, appendicitis can rapidly progress to rupture, which would be a medical emergency.
- Pulmonary embolism: The presence of a middle lobe nodule could also be seen in pulmonary embolism, particularly if the nodule is a result of infarction.
- Malignancy: Although less likely, the middle lobe nodule could represent a malignant process, such as lung cancer or metastasis.
- Rare Diagnoses
- Intussusception: Although rare in adults, intussusception could cause bowel obstruction and appendiceal distension.
- Echinococcal cyst: The middle lobe nodule could represent an echinococcal cyst, although this would be rare in the absence of other systemic symptoms or travel history.
SOAP Note
S - The patient presents with findings concerning for early or developing acute uncomplicated appendicitis and a probable infectious/inflammatory middle lobe nodule. O - The patient has a mildly distended, fluid-filled appendix without surrounding inflammatory fat stranding, and a 9 mm noncalcified middle lobe nodule with surrounding ground-glass opacity. A - The differential diagnosis includes acute appendicitis, probable infectious/inflammatory middle lobe nodule, gastroenteritis, pulmonary granuloma, appendiceal rupture, pulmonary embolism, malignancy, intussusception, and echinococcal cyst. P - The patient should be closely monitored for signs of appendiceal rupture or other complications, and further evaluation, such as laboratory tests and imaging studies, should be considered to confirm the diagnosis and guide management.