Carpal Boss

The carpal boss (carpe bossu) is a bony protuberance at the carpometacarpal joints of the index and middle fingers. It is most commonly caused by an osteophyte at the base of the metacarpal bones originating from the carpometacarpal joint, or less commonly, by a supernumerary bone (e.g, an os styloideum), as seen in the image above. A carpal boss may be accompanied by a small ganglion cyst.

References

Conway WF, Destouet JM, Gilula LA, Bellinghausen HW, Weeks PM. The carpal boss: an overview of radiographic evaluation. Radiology. 1985 Jul;156(1):29-31.

Testicular Microlithiasis

Testicular microlithiasis is an infrequent incidental finding on scrotal ultrasound. An association between testicular microlithiasis and germ cell tumors and testicular carcinoma in situ has been reported. Testicular microlithiasis has also been suggested as a feature of the testicular dysgenesis syndrome, which is thought to be related to subfertility, testicular atrophy, cryptorchidism, germ cell tumors, and other abnormalities of sexual development.

Management of patients with testicular microlithiasis has varied across institutions. A recent review in Nature Reviews: Urology makes the following suggestions:

• Initial evaluation of all patients with testicular microlithiasis: Search for personal and family history of testicular dysgenesis syndrome (e.g., symptoms of subfertility, cryptorchidism, testicular atrophy and germ cell tumors). Obtain a baseline chest radiograph and abdominal ultrasound.
• Asymptomatic and healthy patients 13 to 39 years of age and no features of testicular dysgenesis syndrome: Initial evaluation as above. Monitor with testicular self-examination.
• One or more features of testicular dysgenesis syndrome: Initial evaluation as above plus serum tumor markers. Testicular biopsy for testicular carcinoma in situ may be considered. Annual follow-up with scrotal ultrasound and serum tumor markers.

References

Tan MH, Eng C. Testicular microlithiasis: recent advances in understanding and management. Nat Rev Urol. 2011 Mar;8(3):153-63.

Management of Incidentally Detected Gallbladder Polyps

Gallbladder polyps are seen in about 5% of patients who undergo abdominal ultrasound. The majority of gallbladder polyps are nonneoplastic (cholesterol or inflammatory polyps), and about 30% actually represent small stones misdiagnosed as polyps. The main concern is the rare gallbladder carcinoma, which has a poor prognosis (5-year survival rate of approximately 10%).

The risk of malignancy increases for polyps larger than 10 mm, sessile polyps, single polyps, and polyps with adjacent wall thickening or invasion, and with increasing patient age.

The most recent data suggest that incidentally detected gallbladder polyps ≤ 6 mm may require no additional follow-up. While the data are inconclusive in regards to management of polyps > 7 mm in diameter, cholecystectomy seems to be warranted for lesions > 10 mm.

References

• Corwin MT, Siewert B, Sheiman RG, Kane RA. Incidentally detected gallbladder polyps: is follow-up necessary?--Long-term clinical and US analysis of 346 patients. Radiology. 2011 Jan;258(1):277-82.
• Ito H, Hann LE, D'Angelica M, Allen P, Fong Y, Dematteo RP, Klimstra DS, Blumgart LH, Jarnagin WR. Polypoid lesions of the gallbladder: diagnosis and followup. J Am Coll Surg. 2009 Apr;208(4):570-5.

Churg-Strauss Syndrome

Churg-Strauss syndrome is a systemic vasculitis involving multiple organs. It is seen almost exclusively in patients with asthma, with a mean age of onset of ~40 years. Almost all patients have eosinophilia and up to 75% may have positive ANCA. Eosinophil infiltration into the endocardium induces endocardial thickening, thrombus formation, and myocardial dysfunction, which can be seen in up to 50% of patients. Peripheral neuropathy can also be seen.

The most common findings on radiographs are transient, patchy, nonsegmental opacities without a zonal predilection. Small noncavitary nodules or diffuse reticular opacities may also bee seen.

CT may reveal small (< 10 mm) centrilobular nodules (60% of cases), ground-glass opacities (50%), bronchial wall thickening (50%), bronchial dilatation (50%), consolidation (40%), interlobular septal thickening (40%), mosaic perfusion (50%), and unilateral or bilateral pleural effusion (50%).

Differential considerations include:

• Simple pulmonary eosinophilia: Löffler syndrome.
• Chronic eosinophilic pneumonia:
• Subacute hypersensitivity pneumonitis: May also have small centrilobular nodules or nodular ground-glass opacity.
• Metastatic calcification: May also have small centrilobular nodules or nodular ground-glass opacity.
• Microscopic polyangiitis: May also have small centrilobular nodules or nodular ground-glass opacity.
• Systemic lupus erythematosis: May also have small centrilobular nodules or nodular ground-glass opacity.
• Respiratory bronchiolitis-interstitial lung disease: May also have small centrilobular nodules or nodular ground-glass opacity.

References

Chung MP, Yi CA, Lee HY, Han J, Lee KS. Imaging of pulmonary vasculitis. Radiology. 2010 May;255(2):322-41.

Drainage of the Accessory Hemiazygos Vein into the Left Brachiocephalic Vein

The accessory or superior hemiazigos vein (AHAzV) normally courses to the left of the thoracic spine and crosses to the right at the T7-T8 level to join the azygos vein. In ~75% of cases, there is a small connection between the accessory hemiazygos vein and the left superior intercostal vein (SICV), which normally drains into brachiocephalic vein (BCV). In about 2% of cases, this connection is large enough to allow the accessory hemiazygos vein to drain into the brachiocephalic vein. This is shown in the images above. This variant anatomy may become clinically significant as a collateral pathway in cases of venous obstruction.

This patient also has an azygos lobe and an aberrant right subclavian artery (ARSCA).

SVC, superior vena cava; Ao, aorta.

Radiology

Galwa RP, Prakash M, Khandelwal N. 16-MDCT depiction of accessory hemiazygos vein draining into the left brachiocephalic vein. Indian J Radiol Imaging 2007;17:50-1.

Froupie (4/1998 - 6/1/2011)

The image above shows an enhancing mass of an undifferentiated sarcoma with central necrosis overlying the right shoulder of the best cat in the world. There is involvement of the supraspinatus muscle.

Ovarian Vein Thrombosis

Ovarian vein thrombosis is being diagnosed more frequently due to increased imaging. It can be seen in postpartum women and in women with pelvic inflammatory disease, or a history of pelvic surgery. Bland or tumor thrombosis can be seen in patients with cancer.

Patients may be asymptomatic or present with vague abdominal pain. Pulmonary embolism, sepsis, or even death are dreaded and rare complications.

CT will classically show a "filling defect in a tubular structure anterior to the psoas muscle with a central round low-attenuation center and peripheral higher-attenuation rim."

Postpartum patients and women with pelvic inflammatory disease are treated with intravenous heparin and antibiotics. Patients with a history of pelvic surgery or malignancy are not generally treated unless complicated by thrombophbebitis or pulmonary embolism.

References

• Karaosmanoglu D, Karcaaltincaba M, Karcaaltincaba D, Akata D, Ozmen M. MDCT of the ovarian vein: normal anatomy and pathology. AJR Am J Roentgenol. 2009 Jan;192(1):295-9.
• Yassa NA, Ryst E. Ovarian vein thrombosis: a common incidental finding in patients who have undergone total abdominal hysterectomy and bilateral salpingo-oophorectomy with retroperitoneal lymph node dissection. AJR Am J Roentgenol. 1999 Jan;172(1):45-7.