Differential Diagnosis
- Single most likely diagnosis
- Acute Deep Vein Thrombosis (DVT): The venous Doppler findings of an intravascular filling defect, absent color flow Doppler signal, and absent compressibility in the right proximal and middle segments of the superficial femoral vein are highly suggestive of an acute occlusive DVT, especially in the appropriate clinical setting.
- Other Likely diagnoses
- Chronic Venous Insufficiency: Although the primary finding suggests an acute process, chronic venous insufficiency could be a consideration if the patient has a history of similar symptoms or signs of chronic venous disease, but this would not explain the acute occlusive findings.
- Venous Thrombosis of Other Etiologies: This could include thrombosis due to malignancy, thrombophilic conditions, or other rare causes of venous thrombosis. However, without additional clinical information, these are less likely.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Phlegmasia Cerulea Dolens: A severe form of DVT that can lead to limb ischemia and potentially limb loss if not promptly treated. The presence of significant swelling, pain, and possibly cyanosis would increase suspicion for this condition.
- Pulmonary Embolism (PE): Although the question focuses on lower extremity findings, any condition that increases the risk of DVT also increases the risk of PE, which can be life-threatening. Clinical correlation and possibly further imaging (e.g., CT pulmonary angiogram) might be necessary.
- Rare diagnoses
- Venous Tumors (e.g., Leiomyosarcoma): These are rare tumors that could potentially cause venous obstruction and mimic DVT on imaging.
- Arteriovenous Fistula or Malformation: Although the arterial Doppler shows minimal changes, an arteriovenous fistula could potentially cause venous congestion and mimic some symptoms of DVT, but this would not explain the specific findings of an intravascular filling defect and absent compressibility.
- Other rare causes of venous obstruction, such as external compression from a mass or a Baker's cyst (ruled out in this case), could also be considered but are less likely given the provided information.