Through a systematic review of cases of extrapulmonary tuberculosis confirmed in our hospital in the last 10 years,
we illustrate the most representative confirmed cases and review the radiologic findings of the most common abdominal extrapulmonary affectation.
LYMPHATIC SYSTEM
The lymph nodes are the most frequent finding (55-65%) in tuberculous infection.
They can be enlarged with a hypodense center and peripheral enhancement after administration of intravenous contrast,
which may after a certain length of time calcify.
Histoplasmosis may also be associated with these hypodense nodules; on the contrary,
they are rarely seen in patients with lymphoma.
Other image presentation patterns are shaped as adenopathic conglomerate.
Fig. 8: Unenhanced CT in which multiple partially calcified retroperitoneal lymph nodes were observed. We can also see grade IV hydronephrosis of the left kidney. The patient was diagnosed with genitourinary tuberculosis with nodal longstanding affectation.
References: Servicio de Radiodiagnóstico. Hospital Clínico Universitario de Valencia. Spain.
TUBERCULOSIS OF THE DIGESTIVE TRACT
You can be the tuberculous primary infection´s gateway in areas where bovine tuberculosis is common,
but this form of intestinal tuberculosis is exceptional.
The intestinal infection is usually secondary to swallowing sputum in a smear-positive pulmonary tuberculosis,
to a linfohemaogena’s dissemination,
or to the direct affectation by contiguity.
The ileocecal region,
followed by the proximal colon,
rectum and distal small intestine are the areas most commonly affected.
This tuberculosis can lead to irregular mucosal ulcers,
transverse to the long axis of the intestine,
which can be very large in the colon and can make a fistula,
or may cause inflammation with hypertrophy of the gut wall.
Differential diagnosis includes amebiasis,
cecal carcinoma,
Crohn disease.
TUBERCULOUS PERITONITIS
Peritoneal affectation is frequently seen in association with other forms of gastrointestinal tuberculosis.
There are three types of tuberculosis peritonitis that have been described:
• Wet type: large amounts of viscous ascites that may be of high attenuation on CT and may be loculated.
It is the most frequent.
• Fibrotic-fixed type: omental masses (omental cake),
matted loops of bowel and mesentery and small amounts of ascites.
• Dry or plastic type: caseous nodules,
a fibrous peritoneal reaction and dense adhesions.
Differential diagnosis includes carcinomatosis,
mesothelioma or nontuberculous peritonitis.
It is often very difficult to distinguish TB peritoneal disease from other entities,
so aspiration of any ascitic fluid should be obtained and sent for PCR.
GENITOURINARY TUBERCULOSIS
It is the most common manifestation of extrapulmonary tuberculosis (20%).
It may be caused by hematogenous spread (kidney,
prostate,
seminal vesicles)or by contiguity (bladder,
epididymis).
The radiological findings can be highly variable and nonspecific,
although the combination of three or more findings is highly suggestive of renal tuberculosis.
• Thickening,
mass,
ulceration and subsequent fibrosis with stenosis of the collecting system.
• Erosion of the minor calices (pattern “apolillado") which extend into the adjacent parenchyma and may cause papillary necrosis.
• "Chalice ghost": stenosis can lead to areas without excretion that are dependant of a chalice.
• Hydronephrosis or hidrocalicosis.
• Areas of calcified caseous necrosis and calcification of renal tuberculomas (mastic kidney).
• Cavities in the renal cortex postnecrosis that can communicate with the collecting system.
• Extension perirenal and/or fistulas to adjacent organs.
• Cortico-medullary scars and irregularities in the renal after parenchymal lesions.
• Granular calcifications,
amorphous calcifications and less commonly curved calcifications,
of the renal parenchyma,
which may eventually replace some or all of the renal parenchyma in advanced stages ("autonefrectomía").
Fig. 4: Enhanced CT where an atrophic left kidney was observed with calcifications that completely replace the renal parenchyma.
References: Servicio de Radiodiagnóstico. Hospital Clínico Universitario de Valencia. Spain.
• Extensive ureteral patched stenosis that alternate with dilated areas (ureter “corkscrew").
They can also produce a dilated ureter or wall irregularities ("tooth ureter").
• Meatal stenosis or reflux.
Fig. 5: Curvilinear calcification in left vesicoureteral junction in a patient with longstanding TBC in the urinary tracts. We can also see grade IV hydronephrosis of the left kidney.
References: Servicio de Radiodiagnóstico. Hospital Clínico Universitario de Valencia. Spain.
• Urethral stricture.
BLADDER
In an advanced stage of the disease,
bladder’s capacity is reduced and its walls are irregular.
Calcifications can be associated.
The differential diagnosis in this case would be done with schistosomiasis,
cyclophosphamide cystitis,
post-radiation changes and bladder carcinoma calcified,
but more often,
what happens is that the patient does not have manifestations into another level which could to guide us to the diagnosis of tuberculosis.
GENITAL TUBERCULOSIS
Female genital tuberculosis affects in the 94% of the cases the fallopian tubes causing a bilateral salpingitisthat may evolve into tubo-ovarian abscess and even be spread to the peritoneum.
In men,
the most common genital infection is prostatic abscess,
indistinguishable from the pyogenic.
Epididymitis or orchiepididymitis are usually quite unspecific.
Rarely can the infection infiltrate into the testicle,
being for this reason indistinguishable from a testicular tumor.
LIVER AND SPLEEN
The most common affectation is the miliary that cannot be seen on CT,
with multiple hypodense nodules on CT of 0,5-2mm.
In RM tuberculomas are hypointense on T1,
hyperintense on T2 with peripheral contrast enhancement.
These nodules evolve into calcified granulosmas..
ADRENAL GLANDS
As hepatosplenic affectation,
adrenal glands affectation is quite rare.
It can be seen unilaterally or bilaterally with a clinical picture of addisonian type in an advanced stage of the disease.
In CT we can see enlarged glands,
hypodense areas of necrosis with punctate calcifications.
SPONDYLITIS
Spinal tuberculosis may be indistinguishable from pyogenic spondylitis or vertebral metastatic disease in some cases.
It follows a more insidious path than pyogenic variety.
Although the findings are nonspecific,
some features that guide the diagnosis of tuberculosis are:
• It tends to affect the lower endplates causing chronic destruction of the vertebral body,
causing a marked kyphosis angle ("hump deformity").
On the contrary Brucella spondylitis is usually not associated with kyphosis.
• It is more prevalent in the thoracolumbar junction; Brucella spondylitis has more predilection for the lower lumbar spine
• Calcification of the paraspinal muscles and soft tissue mass associated
•Annular enhancementof the lesions of the vertebral bodies andof the paravertebral abscesses
• Spread underneath the longitudinal ligaments
• Relative preservation of intervertebral discs while pyogenic infections usually present disk destruction
• Several Injuries at different levels
• Lesions are usually larger than in pyogenic spondylitis
TUBERCULOSIS OSTEOARTICULAR
It occurs in less than 5% of TB patients.
It is usually characterized by:
• Monostotic allocation
• Preference for large loading joints (may be peripheral in children "tuberculous dactylitis" and the elderly)
• It causes inflammation of soft tissue areas and regional osteopenia,
which can become severe
• It may cause osteolytic lesions
• It may cause marginal erosions
• It may cause loss of articular cartilage
• It does not usually produce bone fusion
Fig. 10: a) 27-year-old patient with collections in the anterior chest wall affecting the sternum. At first, the diagnosis of osteomyelitis was raised. Finally, it was a TBC.
b) A year later, the patient shows complete resolution of the collection with postsurgical changes in the anterior chest wall.
References: Servicio de Radiodiagnóstico. Hospital Clínico Universitario de Valencia. Spain.
Fig. 11: CT with intravenous contrast of a 28-year-old patient after drainage of tuberculous sacroiliitis. Lytic involvement of the right sacrum and ilium. Multiple collections with high uptake contour adjacent square lumbar muscle, right buttock muscles and retrosomática regarding TBC abscesses.
References: Servicio de Radiodiagnóstico. Hospital Clínico Universitario de Valencia. Spain.
CENTRAL NERVOUS SYSTEM TUBERCULOSIS
This usually occurs secondary to haematogenous spread,
and it can cause:
• Meningitis: Abnormal meningeal enhancement homogenous,
most typically pronounced in the basal cisterns.
Cranial tuberculous meningitis can result in hydrocephalus (communicating hydrocephalus more likely than obstructive hydrocephalus and ischemic infarcts in the basal ganglia and internal capsule due to arteritis or occlusion of small perforating Vessels).
• Tuberculomas: tuberculomas can be solitary or multiple and are usually found in the frontal parietal lobes or as rounded or lobulated homogenous masses with ring enhancement and irregular wall thickness.
On MRI Tuberculomas,
those that are non-caseating are hyperintense on T2WI often with homogenous enhancement,
whereas caseating lesions are hypointense on T2WI.
Differential diagnosis includes toxoplasmosis and fungal infections,
malignancy: such as lymphoma,
metastases and primary brain tumors and other granulomatous disease sarcoidosis.
Fig. 12: Hyperdense intraparenchymal lesions on T2 showing anular enhacement with the administration of contrast in T1, predominantly subcortical distributed in both hemispheres, with involvement of the left basal ganglia, and in a infratentorial level.
References: Servicio de Radiodiagnóstico. Hospital Clínico Universitario de Valencia. Spain.
Fig. 13: Hyperdense intraparenchymal lesions on T2 showing anular enhacement with the administration of contrast in T1, predominantly subcortical distributed in both hemispheres, with involvement of the left basal ganglia, and in a infratentorial level.
References: Servicio de Radiodiagnóstico. Hospital Clínico Universitario de Valencia. Spain.
Fig. 14: Hyperdense intraparenchymal lesions on T2 showing anular enhacement with the administration of contrast in T1, predominantly subcortical distributed in both hemispheres, with involvement of the left basal ganglia, and in a infratentorial level.
References: Servicio de Radiodiagnóstico. Hospital Clínico Universitario de Valencia. Spain.
• Spinal Tuberculous Meningitis: the MR imaging features of spinal tuberculous meningitis include cerebrospinal fluid loculi and obliteration of the spinal subarachnoid space with loss of outline of the spinal cord in the cervicothoracic spine and matting of the nerve roots in the lumbar region.
• Abscesses and cerebritis.
•Central nervous system miliary tuberculosis: numerous round and homogeneously enhancing lesions less than 2 mm diameter.