Extrapulmonary Tuberculosis (MSK, GI, GU, Vascular)
Question and answer review of extrapulmonary tuberculosis of the vascular, genitourinary, gastrointestinal and musculoskeletal systems for radiology board preparation.
Show Notes/Study Guide:
What is a Rasmussen aneurysm?
Pulmonary artery pseudoaneurysm secondary to pulmonary tuberculosis.
Is hemoptysis in general most common from a bronchial artery or pulmonary artery source?
Hemoptysis is 90% of the time from a bronchial artery source. On angiography bronchial artery bleeding may not show a blush of active extravasation but enlarged and tortuous bronchial vessels may signify the source of bleeding.
Is hemoptysis from tuberculosis most common from a bronchial or pulmonary artery source?
Although you can have Rasmussen pulmonary artery pseudoaneurysms with TB, hemoptysis is most common due to TB causing occlusion of pulmonary arterioles causing subsequent bronchial arterial hypertrophy that predisposes to bleeding and the bloody cough associated with TB.
TB most commonly involves which portion of the small bowel?
The terminal ileum. Classic infectious agents that like the terminal ileum on board exams are
tuberculosis, Yersinia, and campylobacter. Can also cause a coned appearance of the cecum with ulcers and narrowing.
GI Tip: Peritoneal carcinomatosis is most common from malignancy such as ovarian, colon, breast, GI cancers. Differential considerations include TB and lymphoma. If peritoneal carcinomatosis is non-malignant TB is a potential cause of this appearance.
True or false? Tuberculosis of the urinary bladder denotes renal involvement of TB.
True. TB of the bladder nearly always has the source from the kidneys. So, with urinary system TB always evaluate the upper and lower urinary tracts. Signs of bladder involvement of TB include urinary bladder pseudodiverticula, urinary bladder wall thickening.
How can you differentiate between renal tuberculosis and nephrocalcinosis?
If you are presented with a single kidney with diffuse parenchymal calcifications think renal tuberculosis rather than nephrocalcinosis. If bilateral think causes of nephrocalcinosis first, with TB on differential, especially if other findings supporting TB.
What are common imaging manifestations of renal tuberculosis?
Broadly can present with a pyelonephritis appearance or a tumor-like appearance with multiple masses. Renal calcifications, tuberculomas around renal collecting systems which can cause infundibular stenosis, renal papillary necrosis. More advanced disease will have ureteral stenosis/stricturing in upper and/or lower tracts with hydronephrosis which, in late stage, can cause autonephrectomy. Advanced disease can also present with diffuse renal amorphous calcification termed ‘putty kidney’. Clinical symptoms include hematuria and flank pain.
What are some common complications of pelvic inflammatory disease from tuberculosis?
Infertility, TB peritonitis and tubo-ovarian abscesses can result from TB pelvic inflammatory disease. On imaging search for fallopian tube stricturing on hysterosalpingography, filling defects in the endometrial cavity, and clue to TB would be calcified lymph nodes in the pelvis/adnexal regions.
What is the most common site of extrapulmonary TB?
Extrapulmonary TB most commonly involves the abdomen generally with the peritoneum being the most common site of TB involvement in the abdomen. On imaging look for peritoneal
nodularity/carcinomatosis, ascites and lymphadenopathy. Can result in omental caking, fibrous
adhesions, and loculated ascites.
True or false? Skeletal TB always secondary to pulmonary TB.
True. Isolated skeletal TB does not happen, at least for board exam purposes.
What is the top MSK site of TB?
The spine.
What is Pott disease?
Pott disease is TB osteomyelitis/diskitis of the spine / TB spondylitis. Most common sites are lower thoracic and upper lumbar spine. Presents with back pain, leg weakness/paraplegia and kyphosis of the thoracolumbar spine. TB involvement is mostly anterior beneath the anterior longitudinal ligament so look for anterior predominant paravertebral inflammation/abscess collections and anterior vertebral body irregularity. Later disease can present with ivory vertebrae (dense vertebral body that is otherwise normal), gibbus deformity (thoracolumbar kyphosis) and/or vertebra plana (compression fracture resulting in pancake like vertebral body)
What are common differential considerations for vertebra plana?
For board exams think Langerhans cell histiocytosis (#1 in children), osteogenesis imperfecta, leukemia, myeloma, metastatic disease, TB, trauma.
After the spine, what is the second most common site of musculoskeletal tuberculosis?
The hip.
Is TB arthropathy most commonly monoarticular or polyarticular?
Monoarticular is most common. Note that TB arthropathy presents like other
inflammatory/infectious arthropathies with peri-articular osteopenia, peripheral osseous erosions, and progressive joint space narrowing.
