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 subtle surrounding ground-glass opacity suggests an infectious or inflammatory etiology.
- Other Likely diagnoses
- Viral pneumonia: The middle lobe nodule with ground-glass opacity could also be consistent with viral pneumonia, especially in the absence of other symptoms.
- Bacterial pneumonia: Although less likely, bacterial pneumonia could also present with a similar radiographic appearance.
- Appendiceal muccele: The fluid-filled appendix could be a muccele, although this would be less likely without other symptoms or signs of appendiceal obstruction.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Appendiceal rupture: Although the current findings do not suggest rupture, it is essential to consider this possibility, as delayed diagnosis can lead to severe consequences.
- Pulmonary embolism: The presence of a middle lobe nodule could be a pulmonary infarct, and it is crucial to consider pulmonary embolism, especially if the patient has risk factors.
- Malignancy: Although less likely, it is essential to consider the possibility of malignancy, especially if the nodule does not resolve with treatment.
- Rare diagnoses
- Hydatid cyst: The fluid-filled appendix could be a hydatid cyst, although this would be rare in this context.
- Echinococcal disease: The middle lobe nodule could be an echinococcal cyst, although this would be rare and typically associated with other symptoms.
SOAP Note
S - The patient presents with a mildly distended, fluid-filled appendix and a 9 mm noncalcified middle lobe nodule with subtle surrounding ground-glass opacity. O - The radiographic findings are consistent with early or developing acute uncomplicated appendicitis and a probable infectious/inflammatory middle lobe nodule. A - The differential diagnosis includes acute appendicitis, probable infectious/inflammatory middle lobe nodule, viral pneumonia, bacterial pneumonia, appendiceal muccele, appendiceal rupture, pulmonary embolism, malignancy, hydatid cyst, and echinococcal disease. P - The patient should undergo further evaluation, including laboratory tests and potentially a follow-up imaging study, to confirm the diagnosis and guide treatment. Antibiotics and appendectomy may be necessary, depending on the final diagnosis.