Sonography of scrotum

Regarding ultrasound of scrotum,
1. Increased blood flow to the epididymis is the most sensitive sign of epididymitis
2. Epidermoid cysts have characteristic alternating hyper and hypoechoic bands
3. Epididymal papillary cystadenomas are associated with Osler-Rendu-Weber syndrome
4. Adenomotoid tumors are the most common spermatic cord tumours.
5. Adenomatoid tumours of the epididymis most often arise from the head.

Answers: F, T, F, F, F

Notes: Increased size of epididymis and/or scrotum is the most sensitive sign of epididymoorchitis on ultrasound. Epididymal papillary cystadenomas are associated with von Hippel Lindau syndrome. Adenomatoid tumors are the most common benign solid tumours of epididymis (most often arise from tail), and lipomas are the commenest spermatid cord tumours.

Reference: Stengel JW et al. Sonography of the scrotum: case based review. AJR June 2008. S35-S45

Gestational Trophoblastic disease

Regarding gestational trophoblastic disease (GTD),

1. Incomplete moles are more likely to undergo malignant change than the complete moles
2. GTD is almost always completely curable with preservation of fertility
3. Lymphnode involvement is a rare feature of choriocarcinoma
4. GTD usually shows low resistance blood flow
5. It is rare to have other metastasis in the absence of lung metastasis

Answers: F, T, T, T, T

Notes: GTD includes complete mole (46XX diploid), incomplete mole (triploid), invasive mole, choriocarcinoma and placental site trophoblastic tumour. 16% of complete and 0.5% of partial moles undergo malignant changes. Lymph node involvement in GTD raises a possibility of rare GTD, placental site trophoblastic tumor, as lymphnode involvement is rare in choriocarcinoma or invasive moles. Uterine volume has prognostic implications in GTD. The normal PI is more than 1.5 and in GTD, there is low resistance flow, leading to decrease in PI. PI indirectly measures tumor vascularity. With exception of vaginal metastasis, it is rare to have other metastsasis in the absence of lung metastasis. The lung metastasis are usually rounded, measuer up to 3 cm, rarely cavitate, can be miliary, may block pulmonary arteris and cause PE symptoms.

Reference: Allen SD et al. Radiology of gestational trophoblastic neoplasia. Clinical Radiology Volume 61, Issue 4, April 2006, Pages 301-313

Lymphoma

Regarding lymphomas,

1. Mesenteric nodes are commonly involved in Hodgkin's lymphoma
2. Nodal extension is contiguous in HL
3. Extranodal disease is common in NHL
4. Testicular lymphoma is the most common testicular tumor in people aged over 60 years
5. Adrenals are common extranodal sites for lymphomatous involvement

Answers: F, T, T, T, F

Notes: Axial, peripheral and mesentric nodes are commonly involved in NHL and mesentric nodes are rarely involved in HL. Nodal extension may be non-contingious in NHL, usually contigious (more often single nodal group) in HL. Extranodal disease is rare in HL (4-5%), common in NHL (20-40%). Lymphomatous involvement of kidneys is usually bilateral and contiguous retroperitoneal extension is seen with renal lymphoma in 25% and should not be mistaken for RCC. Involvement of adrenal in is rare (only 4% of NHL). In up to 40%, testicular lymphoma is bilateral and multifocal and is most common testicular tumor in people over 60 years. Gastric lymphomas account for 3-5% of gastric malignancies and far less common than adenocarcinomas and GISTs.

References:
Liete NP et al. Cross-sectional Imaging of Extranodal Involvement in Abdominopelvic Lymphoproliferative Malignancies.RadioGraphics 2007;27:1613-1634

Tuberculosis

Regarding tuberculosis,

1. Radiographic evidence of hilar lymphadenopathy is more common in adults than in children
2. Cavitation is hallmark of post-primary TB
3. In TB meningitis, abnormal meningeal enhancement is more often seen in the basal cisterns
4. In spinal TB, calcification of abscess is characteristic
5. Calcification is seen more than 50% of renal TB

Answers: F, T, T, T, T

Notes: Radiographic evidence of lymphadenopathy is more common in children (96%) than in adults (46%) and more often seen in the right hilar and right paratracheal location. Cavitation is hallmark of post-primary TB, where as lymphadenopathy is rare (5%). Calcification of abscess is highly specific of TB spine. In renal TB, calcification is seen in more than 50% and the other findings include calcyceal deformity and papillary necrosis.

Reference: Burrill J et al. Tuberculosis: A Radiologic Review. RadioGraphics 2007;27:1255-1273

Benign scrotal tumors

Regarding benign scrotal tumors,

1. Alternating low and high echogenic rings are pathognomonic for epidermoid cyst
2. Leydig cell hyperplasia may be seen as multiple small areas of hyperechogenicities
3. Epididymal cystadenoma is the most common epididymal tumor
4. Epididymal cystadenomas are associated with Von-Hippel-Lindau syndrome
5. Scrotal pearls have a high association of seminomas

Answers: T, F, F, T, F

Notes: Onion peel appearance of a testicular mass is virtually diagnostic of a epidermoid cyst. Leydig cell hyperplasia may be seen as multiple small areas of hypoechogenicities. Adenomatoid tumor is the most common epididymal tumor. Scrotal pearls are fibrous pseudotumors and are not associated with increased risk of malignancy

Reference: Kim W et al. US–MR Imaging Correlation in Pathologic Conditions of the Scrotum. RadioGraphics 2007;27:1239-1253

Malignant testicular tumors

Regarding malignant testicular tumors,

1. 95% of malignant testicular tumors are of germ cell origin
2. Seminomas more often demonstrate calcifications compared to non-seminomatous tumors
3. Seminomas typically show well defined high signal mass on T2WI
4. Intratesticular calcification may be secondary to spontaneous regression of germ cell tumors
5. MRI usually differentiate seminomas from non-seminomatous germ cell tumors

Answers: T, F, F, T, F

Notes: 95% of malignant testicular tumors are of germ cell origin, in which seminomas are the most common type. Non-seminomatous germ cell tumors more often demonstrate calcifications, hemorrhage, fibrosis and cystic changes compared to seminomas. Germ cell tumors usually are isointense on T1 and hypointense on T2WI and it is not possible to differentiate seminomas from non-seminomatous lesions. Germ cell tumors may undergo spontaneous regression and may be seen as hypoechoic area or calcification

Reference: Kim W et al. US–MR Imaging Correlation in Pathologic Conditions of the Scrotum. RadioGraphics 2007;27:1239-1253

Renal trauma

Regarding blunt injury of the kidney,

1. Nearly 50% of renal injuries are treated surgically
2. Presence of hematuria is an idication of serioud renal injury
3. Absence of hematuria excludes renal injury
4. Cortical rim sign on CT scan suggests devascularization
5. Hypertension is a known late complication of renal trauma

Answers: F, F, F, T, T
Notes: About 95% of isolated renal injuries are minor and are managed conservatively. Hematuria is seen in 95% of renal injuries, but absence of hematuria does not exclude renal trauma. Hematuria may be absent in severe renal trauma (25% of renal artery thrombosis may not have hematuria). Hematuria with hypotension is associated with increased risk of significant renal injury; but there is poor correlation between severity of hematuria and severity of renal injury. Complete devascularization shows absent nephrogram or cortical rim nephrogram. Early complications include urinary extravasation and urinoma formation, delayed bleeding, infection of the urinoma, perinephric abscess, sepsis, arteriovenous fistula, pseudoaneurysm and hypertension. Late complications include hydronephrosis, hypertension, calculus formation and chronic pyelonephritis.
References:
1. Fanney DR et al.CT in the diagnosis of renal trauma. RadioGraphics 1990; 10: 29.S201-214
2. Kawashima A et al.Imaging of Renal Trauma: A Comprehensive Review. RadioGraphics 2001; 21: 57

Epidermoid cyst of the testis

Regarding epidermoid cysts of the testis,

1. Epidermoid cysts are one of the common cysts of the testis
2. Epidermoid cysts are commonly associated infertility
3. Epidermoid cysts are commonly multiple
4. The ultrasonic appearances are characteristic for epidermoid cysts
5. On Gd administration, epidermoid cysts usually enhance

Answers: F, F, F, T, F
Notes: Epidermoid cyst is a rare benign lesion of the testis (1%–2% of testicular lesions). Commonly the patients present between 2nd and 4th decades. Most of the epidermoid cysts are single and unilateral. Multiple or bilateral cysts are associated with Gardner syndrome, Klinefelter syndrome and cryptorchid testes. They are filled with laminated cheesy material. The clinical management is controversial and recently, organ-preserving surgery has been favored over traditional orchidectomy.Most patients present with painless mass, but a few complain of pain or discomfort.
US may show an echogenic centre surrounded by a hypoechoic ring and hyperechogenic rim, causing 'bull’s-eye' or 'target' lesion; or alternating hypoechoic and hyperechoic concentric rings, causing 'onion skin appearance'. The lesions are not vascular.MR shows low signal peripheral rim on both T1- and T2-weighted images and a circumferential high signal zone surrounding a low-signal central zone, or alternating concentric rings of low and high signal on T1- and T2-weighted images. On contrast, there is no enhancement.The central echogenic center may represent keratin debris and the concentric layeers may represent lipid and water containing materials. The squamous cell capsule causes hyperechoic rim.
The 'onion ring' appearance is charecteristic for an epidermoid cyst, although not pathognomonic. Simple and tunica albuginea cysts are anechoic. Tumors, abscesses and chronic inflammatory processes may have capsule, but are likely to show hypervascularity. Neoplasms usually enhance on Gd-enhanced MR. Hemorrhage may have heterogenous appearance on ultrasound.
References:
1. Cho JH et al. Sonographic and MR Imaging Findings of Testicular Epidermoid Cysts. AJR 2002; 178:743-748
2. Loya AG et al. Epidermoid Cyst of the Testis: Radiologic-Pathologic Correlation. RadioGraphics 2004; 24: S243-S246.
3. Woodward PJ et al. From the Archives of the AFIP: Tumors and Tumorlike Lesions of the Testis: Radiologic-Pathologic Correlation. RadioGraphics 2002; 22: 189.

Angiomyolipoma of the kidneys

Regarding Angiomyolipomas (AML),

1. AMLs associated with tuberous sclerosis are more common than sporadic ones
2. Females are more commonly affected than males in both sporadic type and in those with tuberous sclerosis
3. AMLs are associated with neurofibromatosis
4. The most common complication is malignant transformation
5. AMLs are not suitable for embolization

Answers:F, T, T, F, F
Notes: AMLs are benign hamratomas. Sporadic type is usually seen between 50 and 80 years, has a female preponderance and comprises 80% of AMLs. AMLs are commonly seen in tuberous sclerosis (wide range, 20-80%) and also has a female prediliction. AMLs are associated with neurofibromatosis and VHL syndrome. Retroperitoneal haemorrhage is the most common and life threatening complication. The larger the tumour, the greater is the risk of haemorhage; hence AMLs larger than 4 cm are usually treated and the rest are followed. Embolization is increasing used to treat hypervascular AMLs.
References:

1. Rimon U et al. Larger renal angiomyolipomas: DSA grading and presentation with bleeding. Clin Rad (2006) 61, 520-526
2. Dahnert W. Radiology review manual 5th edition. Lippincott Williams & Wilkins.

Endometrial carcinoma

(1) Regarding the endometrial carcinoma,

1. In Europe, endometrial carcinoma is second most common gynaecological malignancy, following cervical carcinoma.
2. In the UK, most of the endometrial carcinomas present late
3. FIGO Staging is based on MRI the of the pelvis and CT scan of the abdomen.
4. Endometrial carcinoma accounts for approximately 10% of postmenopausal bleeding
5. The incidence of nodal metastasis is 3% with deep myometrial invasion (stage IC).

Answers: F, F, F, T, F
(2) Regarding endometrial carcinoma,

1. CT is more accurate than endovaginal ultrasound in the diagnosis of myometrial invasion.
2. Zonal uterine anatomy is best seen on the T1WI.
3. Endometrial carcinoma is typically of low signal on the T2WI.
4. Endometrial carcinoma is of high signal compared to cervical stroma on the T2WI.
5. Lung is the most common site of distant metastasis

Answers: F, F, T, T, T
Notes:
Endometrial carcinoma is the most common gynaecological malignancy, followed by cervical carcinoma. Most of them present early, 75-80% in stage I, and have a good prognosis. Endometrial carcinoma accounts for 7-14% of post menopausal bleeding. FIGO staging is surgical and pathological based as clinical staging is inaccurate. FIGO does not consider imaging in the staging. However, the role of MRI in the diagnosis of myometrial and cervical invasion is increasing recognised. The incidence of nodal involvement is 3% with stage IB and 40% with stage IC and MRI may play an important role in this. Lymphadenectomy is done for Grade I/II with more than 50% myometrial invasion and for all grade III disease. A large randomised ASTEC (A Study in the Treatment of Endometrial Cancer) is being carried out to address role of lymhadenectomy and post-operative radiotherapy.
Overall accuracy of MRI is 83-92% and endovaginal ultrasound (77%) is more accurate than CT(61-76%) in predicting the myometrial invasion. Zonal anatomy is best seen on the T2WI and endometrial carcinoma is typically of low signal on the T2WI and enhance more slowly than myometirum on the dynamic enhancement scan. Inner myometrium is brighter than outer myometrium on dynamic MRI and maximum contrast between the two occurs at 50s. Endometrial carcinoma is of high signal compared to cervical stroma on T2WI.
Reference: Barwick TD et al. Imaging of endometrial carcinoma. Clin Rad (2006) 61, 545-555

Trophoblastic Disease

Regarding imaging of the gestational trophoblastic neoplasia (GTN),

1. Partial hydatidiform moles are more premalignant than the complete hydatidiform moles.
2. GTNs are almost always curable.
3. In GTNs, the uterine artery pulsatility index (PI) has been shown to predict methotrexate resistance.
4. Metastases typically occur in the peritoneum.
5. Uterine artery embolization (UAE) has a proven therapeutic effect in the management of post GTN vascular malformations.

Answers: F, T, T, F, T
Notes:16% of the complete and 0.5% of the partial moles can transform into malignant forms, i.e., invasive mole, choriocarcinoma and placental site trophoblastic tumour (PSTT). GTN has excellent prognosis and are almost always curable with methotrxate or actinomycin-D. USG and MRI show 'cluster of grape' or 'sand storm' appearance. GTN shows low impedence, high velocities (low PI) in the arteries. The uterine artery PI is known to predict response to chemotherapy. With the exception of vaginal disease, it is rare to have other metastatic disease in the absence of lung disease. Liver metastasis is a marker of poor outcome. Up to 15% of GTNs develop vascular malformations and UAE has been used successfully to treat them. Hyperthyroidism is a rare complication of GTN.
Reference: Allen SD et al. Radiology of gestational trophoblastic neoplasia. Clin Rad 2006:61:301-313.