Uroradiology & genital male imagingCase Type
Marta Manso, Ana Germano, Fernando Ferrito, André BarceloPatient
39 years, male
A 39-year-old male was admitted for right side scrotal pain. No fever, dysuria or trauma were noted. Physical examination revealed pain during palpation and no nodules or inflammatory signs. Laboratory findings showed leukocytosis, C-reactive protein elevation (6.05 mg/dL) and a SARS-Cov2 RT-PCR positive test. An ultrasound evaluation was requested.
B-mode and colour Doppler testicular ultrasound revealed enlargement of the right testicle and heterogenic parenchyma echostructure with a nodular shape hypoechogenic area in the anterior region of the right testicle (Fig. 1, 2). This nodular area had no detectable Doppler sign, and hypervascularization of the remaining parenchyma was seen, suggesting focal infarction (Fig. 3). There was also a small ipsilateral reactive hydrocele. Epididymis had no remarkable alterations, and left testicle ultrasound evaluation was normal.
Segmental testicular infarction was assumed, and he was treated conservatively. Thirteen days after he had no pain, biochemistry normalized, and repeat ultrasound revealed a reduced infarct volume (Fig. 4).
Segmental testicular infarction (STI) is characterized by localized infarct of the testis. It´s a rare condition that affects patients in their second to fourth decade. 
Disease pathogenesis is not well established. Some segmental areas are considered functional end organs and reduction of blood flow from different etiologies can presumably cause infarction. 
Most cases are idiopatic but STI is frequently associated with acute epididymo-orchitis, testicular torsion, blunt trauma, blood hypercoagulability states, vasculitis, hypersensitivity angiitis, infection and iatrogenic vascular injury. 
SARS-CoV-2 infection has been associated with orchitis, vascular changes, Leidig and Sertoli cell scarcity and reduced spermatogenesis.  SARS-CoV-2 may enter the host cell by binding to angiotensin-converting enzyme 2 (widely expressed in testicular cells). Associated vasculopathy has been documented in almost any organ, and although not proven as a causative agent in the present case, virus-induced damage cannot be excluded. 
STI usually presents as acute scrotal pain, and swelling and palpation may be normal. Differential diagnosis includes hypovascular tumours and testicular torsion.
Diagnosis is possible with B mode and colour Doppler ultrasound. The infarcted segment is seen as a well-defined, wedge-shaped or round lesion. In 74% of cases, the lesion is hypoechoic, 21% have mixed echogenicity and 5% are hyperechoic. Doppler ultrasound is essential to determine absent or reduced flow in that same area. Perilesional hyperemia has also been described. [1,2]
Acute phase lesions have heterogeneous echogenicity and evolve progressively to more homogeneously echogenicity becoming hypoechoic and discrete with time. 
In ambiguous cases, contrast-enhanced ultrasound improves accuracy and infarction is seen as an ischemic lobule with perilesional enhancement rim. MRI can also be used with T2 images showing a well-defined border and enhanced T1-weighted images showing an enhanced rim surrounding infarction. 
Conservative treatment with a watchful waiting approach has become the standard treatment. Clinical and radiological presentations of testicular tumours and segmental infarction can appear similar, leading to diagnosis doubts and frequent unnecessary surgical approaches. 
Segmental testicular infarction is rare and presents as a diagnostic challenge easily confused with testicular torsion or tumour.
Knowledge of this entity is essential for differential diagnosis and to avoid unnecessary surgical intervention.
SARS-CoV-2 infection is associated with testicular damage, and awareness should be raised to the presence of testicular pain in this context.
 Aquino Michael, et al. (2013) Segmental Testicular Infarction: sonographic Findings and Pathologic Correlation. J Ultrasound Med. 32:365-372. (DOI:10.7863/jum.2013.32.2.365).
 Smets T, Reichman G, Michielsen DPJ. (2017) Segmental testicular infarction: a case report. Journal of Medical Case Reports. 11:140. (DOI:10.1186/s13256-017-1308-1).
 Duarte-Neto AN, et al. (2021) Testicular pathology in fatal COVID-19: a descriptive autopsy study. Andrology. 2021; 1-11. (DOI:10.1111/andr.13073).
 La Marca A, et al. (2020) Testicular pain as an unusual presentation of COVID-19: a brief review of SARS-CoV-2 and the testis. RBMO. 41:5. (PMID: 32826162).
 Bak-Ipsen CB, et al. (2020) Segmental testicular Infarction – is conservative management feasible? Ultrasound Int Open. 6: E50-R52. (PMID: 33195968).
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