Target Sign Research Articles

MR imaging features and a redefinition of the classification system for nodular fasciitis.

To analyze magnetic resonance imaging features of nodular fasciitis and redefine the system for classifying this class of lesions.Twenty-seven patients with nodular fasciitis and 71 patients with other soft tissue lesions who underwent surgery or biopsy were retrospectively analysed. Demographic information, medical history, and magnetic resonance imaging features were collected. Classification of nodular fasciitis was performed based on a redefined system. Comparison between 2 groups was performed with Chi-square or Fisher exact test.For nodular fasciitis, the longest average lesion diameter was 1.87 cm (range, 0.52–5.46 cm), and 40.7% of lesions were located in the upper extremities, while 29.6% were located in the head and neck. Compared with skeletal muscle, most lesions exhibited isointensity on T1-weighted imaging and hyperintensity on T2-weighted imaging, and 45.5% of the lesions exhibited rim enhancement, 40.9% showed obvious homogenous enhancement, while 13.6% showed no enhancement or slight enhancement. The subcutaneous type accounted for 25.9% of cases, the fascial type 25.9%, the intramuscular type 29.6%, and the unclassified type 18.5%. The “fascia tail sign” was more frequently observed in nodular fasciitis than in other soft tissue lesions (P < .001). Nodular fasciitis was slightly more likely to present with the “inverted target sign” and “solar halo sign” than other soft tissue lesions (P > .05). The “cloud sign” only appeared in nodular fasciitis (P < .05).The “fascia tail sign” and “cloud sign” could help differentiate nodular fasciitis from other soft tissue lesions. A new classification may improve understanding about nodular fasciitis.

AB026. PP-5 Petersen hernia—a rare cause of acute abdomen after laparoscopic gastric by-pass operation

: Petersen’s hernia is a rare type of internal herniation and it has been reported in the literature after Laparoscopic Roux-en-Y gastric bypass (LGB) which is one of the most common bariatric surgical methods. A 27-year-old female patient with a history of LGB operation 2 years ago at the outpatient clinic for obesity presented to the emergency department with complaints of abdominal pain, nausea and vomiting persisting for two days. On her physical examination, there was tenderness, with defense and rebound markedly in the upper left quadrant of abdomen. Laboratory tests were unremarkable except for leukocytosis. Abdominal X-ray showed air fluid levels. Abdomen computerized tomography (CT) was compatible with mechanic bowel obstruction. Explorative laparotomy was performed due to signs of acute abdomen and mechanic bowel obstruction. During laparotomy, it was observed that the small intestines herniated into the space between Roux leg and transverse colon mesocolon which called as “Petersen hernia”. After reducing the incarcerated small intestines without resection, hernia defect was repaired by non-absorbable suture material. Postoperative follow-up period was unremarkable. The patient was discharged postoperative fifth day without any complication. Internal herniation often presents with non-specific findings. It does not show any clinical findings unless strangulation or incarceration occurs. It is a rare clinical condition that may occur in the early postoperative period and may occur many years later. It has been reported in the literature that the incidence of internal herniation is increased in patients who underwent LGB, which is one of the bariatric surgery methods. These patients often present to the emergency department with non-specific complaints such as abdominal pain, nausea and vomiting. Abdomen CT with oral and intravenous contrast is important in the diagnosis of the disease. Thickening of intestinal loops, dilated bowel loops, target sign and abnormal clustering of intestinal loops may be helpful in diagnosis. Petersen hernia should be kept in mind in patients with a history of bariatric surgery presenting with abdominal pain Delays in diagnosis can result in incarceration or strangulation with high mortality and morbidity. In conclusion, closure of meso openings during LGB operations reduces the formation of Petersen hernia that may develop in early and late postoperative periods. It will reduce the mortality and morbidity secondary to Petersen hernia.

Peripheral Nerve Sheath Tumors of Head and Neck: Imaging-Based Review of World Health Organization Classification.

We aim to review the imaging appearance of peripheral nerve sheath tumors (PNSTs) of head and neck according to updated fourth edition of World Health Organization classification. Peripheral nerve sheath tumor can be sporadic or associated with neurofibromatosis type 1, neurofibromatosis type 2, and schwannomatosis. Schwannoma is the most common benign PNST that can be intracranial or extracranial and appears heterogeneous reflecting its histologic composition. Melanotic schwannoma is a different entity with high prediction of malignancy; it shows hypointense signal on T2-weighted image. Neurofibroma can present by localized, plexiform, or diffuse lesion. It usually appears homogeneous or shows a characteristic target sign. Perineurioma can be intraneural seen with the nerve fiber or extraneural appearing as a mass. Solitary circumscribed neuroma and neurothekeoma commonly present as dermal lesions. Nerve sheath myxoma may exhibit high signal on T1 weighted image. Benign triton tumors can be central, aggressive lesion, or peripheral nonaggressive lesion. Granular cell tumor shows hypointense signal on T2 weighted image. Neuroglial heterotopia most commonly occurs in the nasal cavity. Ectopic meningioma arises from ectopic arachnoid cells in the neck. In hybrid PNST, combined histological features of benign PNST occur in the same lesion. Malignant PNSTs are rare with an aggressive pattern. Computed tomography and magnetic resonance imaging are complementary studies to determine the location and extent of the tumor. Advanced magnetic resonance sequences, namely, diffusion-weighted imaging and dynamic contrast enhancement, can help in differentiation of benign from malignant PNST.

Histopathological explanation of the MRI target sign in extra-axial schwannomas

BackgroundTo better understand the nature of magnetic resonance imaging (MRI) findings in schwannomas, especially in the “target sign” of these findings, the histopathological investigation was performed. MethodsThe MRI findings were correlated with histopathological features in 22 samples of schwannomas, which were mostly resected from the extremities. The histopathological analyses included alcian blue staining and immunohistochemical staining for S-100 protein, proliferating cell nuclear antigen (PCNA) and epithelial membrane antigen (EMA). ResultsSeven of the 22 samples of schwannomas of the extremities exhibited target signs including a peripheral zone of homogeneously high signal intensity and a central zone of heterogeneous signal intensity in T2-weighted images. Gadolinium-enhanced T1–weighted images demonstrated a central heterogeneous enhancement and a peripheral ring of homogeneously low signal intensity. Histopathologically, S-100 and PCNA were positive only in the central heterogeneous signal area. In contrast, EMA was only stained on the degenerative epi/perineurium in the peripheral zone. ConclusionIn schwannomas of the extremities showing target sign in T2-weighted images, histopathologically, the peripheral areas were suggested to be mucinous degeneration of the epineurium or perineurium, while the central areas were composed of truly neoplastic cells.

The Target Sign and Its Variant in COVID-19 Pneumonia.

HomeRadiology: Cardiothoracic ImagingVol. 2, No. 4 PreviousNext Images in Cardiothoracic ImagingFree AccessVascular ImagingThe Target Sign and Its Variant in COVID-19 PneumoniaLucas de Pádua Gomes de Farias , Fernando Henrique Caixeta Souza, Gustavo Borges da Silva TelesLucas de Pádua Gomes de Farias , Fernando Henrique Caixeta Souza, Gustavo Borges da Silva TelesAuthor AffiliationsFrom UnitedHealth Group Brazil, Hospital Samaritano, R. Conselheiro Brotero 1486, Higienópolis, São Paulo, SP 01232-010, Brazil.Address correspondence to L.d.P.G.d.F. (e-mail: [email protected]).Lucas de Pádua Gomes de Farias Fernando Henrique Caixeta SouzaGustavo Borges da Silva TelesPublished Online:Aug 13 2020https://doi.org/10.1148/ryct.2020200435MoreSectionsPDF ToolsImage ViewerAdd to favoritesCiteTrack Citations ShareShare onFacebookTwitterLinked In The target sign, identified at chest CT, has been recently described by Müller et al (1) as a nodular opacity in the center of a ring-like opacity in patients with pneumonia caused by the severe acute respiratory syndrome coronavirus 2. Pulmonary vascular alterations are significantly associated with coronavirus disease 2019 (COVID-19) (2,3), and lung autopsies showed distinctive vascular features characterized by endothelial injury with disrupted cell membranes (endothelialitis), widespread thrombosis with microangiopathy, and angiocentric inflammation (4). Thus, the central nodular opacity may reflect the perivascular inflammation or focal enlargement of the pulmonary artery (1). Furthermore, the ring-like opacities may be correlated with the underlying pathophysiologic mechanisms of the disease process as it organizes, indicating that the organizing pneumonia is one of the mechanisms of lung injury, but distinct from the reversed halo sign and the perilobular opacity (1). The variant of target sign here described is characterized by multiple concentric perivascular ring-like opacities. Further evaluation and pathologic studies are required to investigate the contribution of this sign in the diagnosis of COVID-19 pneumonia (Figs 1, 2).Figure 1: Schematic drawing, A, E, and chest CT images (B, axial, C, coronal, D, sagittal, and E, sagittal oblique) show the target sign characterized by nodular opacity in the center of a ring-like opacity. Some multiplanar reformatted planes, E, show the central nodule as a pulmonary arteriole (arrowhead) with perivascular ground-glass tubular opacity, as illustrated in F.Figure 1:Download as PowerPointOpen in Image Viewer Figure 2: Schematic drawing, A, and chest CT images (B-D, axial oblique, E, coronal, and F, sagittal) show the variant target sign characterized by multiple concentric ring-like opacities with a central nodular peribronchovascular opacity.Figure 2:Download as PowerPointOpen in Image Viewer Disclosures of Conflicts of Interest: L.d.P.G.d.F. disclosed no relevant relationships. F.C.S. disclosed no relevant relationships. G.T. disclosed no relevant relationships.Keywords: Adults and Pediatrics, CT, Infection, Lung, Thorax, Vascular Authors declared no funding for this work.

Multi-slice spiral CT evaluation of chronic radiation colitis and rectitis.

The aim of the present study was to retrospectively analyse the multi-slice spiral CT (MSCT) findings of radiation colitis and rectitis (RC&R). A total of 23 cases of RC&R detected by helical CT were included. The CT findings and clinical and endoscopy data of the patients were reviewed. The primary tumours included cancers of the cervix (n=17), rectum (n=4), ovaries (n=1) and bladder (n=1). The total dose of radiation per patient was 46-60 Gy (mean, 49.7 Gy) delivered over 5 weeks. The CT manifestations included different degrees of increased thickness of the intestinal wall (n=20, 87.0%), with a maximum thickness of 16.6 mm. On enhanced CT, the target sign was observed (n=16, 69.9%), with an obviously enhanced mucosa and/or serosa and the following changes observed: Oedema and increased density of the mesentery (n=15, 65.2%); increased density of the subcutaneous fat, and blurred and oedematous pelvic wall muscles (n=4, 17.4%), with the obturator internus and levator ani muscles being most commonly affected; narrowed intestinal lumen (n=3, 13.0%); and a small amount of ascitic fluid (n=2, 8.7%) located in the paracolic sulci and bladder or Douglas pouch. The 23 patients underwent colonoscopy and were diagnosed with RC&R. The major manifestations included telangiectasia and mucosal hyperaemia (n=21, 91.3%). MSCT of chronic RC&R (CRC&R) was associated with certain characteristic findings, which, combined with a medical history of radiotherapy and the clinical manifestations, may prove to be of value in the diagnosis of CRC&R.

Imaging of non-neurogenic peripheral nerve malignancy-a case series and systematic review.

To evaluate the frequency, clinico-pathologic and imaging features of malignant tumors in peripheral nerves which are of non-neurogenic origin (non-neurogenic peripheral nerve malignancy-PNM). We retrospectively reviewed our pathology database for malignant peripheral nerve tumors from 07/2014-07/2019 and performed a systematic review. Exclusion criteria were malignant peripheral nerve sheath tumor (MPNST). Clinico-pathologic and imaging features, apparent diffusion coefficient (ADCmin), and standard uptake values (SUVmax) are reported. After exclusion of all neurogenic tumors (benign = 196, MPNST = 57), our search yielded 19 non-neurogenic PNMs (7%, n = 19/272), due to primary intraneural malignancy (16%, n = 3/19) and secondary perineural invasion from an adjacent malignancy (16%, n = 3/19) or metastatic disease (63%, n = 12/19). Non-neurogenic PNMs were located in the lumbosacral plexus/sciatic nerves (47%, n = 9/19), brachial plexus (32%, n = 6/19), femoral nerve (5%, n = 1/19), tibial nerve (5%, n = 1/19), ulnar nerve (5%, n = 1/19), and radial nerve (5%, n = 1/19). On MRI (n = 14/19), non-neurogenic PNM tended to be small (< 5cm, n = 10/14), isointense to muscle on T1-W (n = 14/14), hyperintense on T2-WI (n = 12/14), with enhancement (n = 12/12), low ADCmin (0.5-0.7 × 10-3mm2/s), and variable metabolic activity (SUVmax range 2.1-13.1). A target sign was absent (n = 14/14) and fascicular sign was rarely present (n = 3/14). Systematic review revealed 89 cases of non-neurogenic PNM. Non-neurogenic PNMs account for 7% of PNT in our series and occur due to metastases and primary intraneural malignancy. Although non-neurogenic PNMs exhibit a non-specific MRI appearance, they lack typical signs of neurogenic tumors such as the target sign. Quantitative imaging features identified by DWI (low ADC) and F18-FDG PET/CT (high SUV) may be helpful clues to the diagnosis.

A Case of Kawasaki Disease with Intussusception

Kawasaki disease (KD) is a systemic vasculitis of unknown cause and is associated with various digestive disorders, although only a few cases of intussusception associated with KD have been reported. We describe a case of intussusception followed by KD in a 3-year-old boy. The patient was admitted to our hospital for evaluation of severe abdominal pain. Because the target sign was seen on ultrasonography, intussusception was diagnosed and hydrostatic reduction was performed. On the second day after admission, he developed a high fever (38°C) and an irregular rash over his whole body. On the fourth day after admission, the high fever continued, and bilateral nonexudative conjunctivitis, erythema of the lips and oral mucosa, strawberry tongue, indurated edema of the dorsa of the hands and feet, and diffuse erythema of the palms and soles appeared, and KD was ultimately diagnosed. He was treated with intravenous immunoglobulin 2 g/kg, aspirin 30 mg/kg/day, and prednisolone 2 mg/kg/day. The high fever and other clinical symptoms resolved immediately after the start of treatment. There was no relapse of KD symptoms after initial treatment, and periungual desquamation was observed on the 10th day after admission. He was discharged on the 15th day, without abnormalities such as coronary dilatation, 3 months after the onset of KD symptoms. Patients with intussusception and KD were older (≥3 years vs <3 years) than those with intussusception alone. In addition, the site of intussusception in KD was mainly colonic rather than ileocolic. If intussusception precedes development of the characteristic clinical symptoms of KD, diagnosis of KD may be delayed. KD should be considered in children older than 3 years with intussusception at a colonic site.

MRI features predict microvascular invasion in intrahepatic cholangiocarcinoma

BackgroundThe presence of microvascular invasion (MVI) in intrahepatic cholangiocarcinoma (ICC) is a significant adverse prognostic factor. This study sought to investigate the correlation between preoperative imaging parameters and MVI in ICC.MethodsA total of 108 patients with surgically resected single ICC tumors (34 MVI-positive and 74 MVI-negative lesions) who underwent MRI examination, including T1WI, T2WI, DWI, and dynamic enhancement imaging, were enrolled in this retrospective study. The following qualitative and quantitative characteristics were evaluated: tumor morphology, signal features on T1WI and T2WI, intrahepatic duct dilatation, hepatic capsule retraction, target sign on DWI, dynamic enhancement pattern, arterial phase enhancement pattern, dot−/band-like enhancement inside the tumor, visible vessel penetration inside the tumor (hepatic artery, portal vein, or hepatic vein), integrity of the enhancement edge of the arterial phase, peripheral hepatic enhancement, tumor size, maximum enhancement edge thickness, arterial edge enhancement ratio, and delayed phase enhancement ratio. Other clinicopathological features were also used to predict and evaluate MVI in ICC. Chi-square test, Fisher’s exact test, and independent t-test were used for univariate analysis to determine the relationships among the presence of MVI and these MR parameters. Logistic regression analysis was used to identify predictors of MVI among these MR parameters.ResultsAmong MRI characteristics, tumor morphology, intrahepatic duct dilatation, arterial phase enhancement pattern, visible hepatic artery penetration sign, maximum diameter of the tumor and the arterial phase edge enhancement ratio were correlated with MVI (P = 0.007, 0.003, 0.008, 0.000, 0.003, and 0.002, respectively). Furthermore, higher CA19–9 levels (≥37 U/ml) and pathological tumor grade III were also related to MVI (P = 0.014 and 0.004, respectively). However, multivariate logistic regression analysis demonstrated that none of the parameters were independent risk factors for the diagnosis of MVI in ICCs.ConclusionFor the preoperative prediction of MVI in ICC, six qualitative and quantitative data obtained on preoperative MRI, as well as one tumorigenic marker and the pathological tumor grade, were statistically significant. More research is needed to identify MR characteristics that can be used as independent risk factors.

MR Target Sign in Cerebral Aspergillosis.

Magnetic resonance (MR) is an effective imaging modality in the evaluation of infectious brain disease, yet findings are often nonspecific. The presence of a diagnostic feature can facilitate early treatment, particularly where mortality is high. We highlight MR apparent diffusion coefficient/T2-weighted target sign in the diagnosis of cerebral aspergillosis.

SAT-390 Preoperative Parathyroid Ultrasound Imaging - Pitfalls and Ways to Improve Diagnostic Accuracy

Introduction: Parathyroid ultrasound (US) is commonly used for pre-operative imaging to facilitate focused parathyroid surgery. It provides point-of-care imaging without ionizing radiation and is less expensive compared to nuclear scintigraphy or computed tomography (CT). Parathyroid US is, however, operator skill and experience dependent. Methods: The charts of all patient who underwent parathyroid surgery between 2016 and 2018 were reviewed. Investigators reviewed the pre-operative US images and correlated these findings with pathology reports, operative notes and with results of CT and nuclear scintigraphy imaging. The US characteristics of parathyroid lesions were described. Results: In total 146 patients underwent parathyroid surgery during the three-year study period. The average age of the cohort was 55.1 +/- 15.1 years and the male to female ratio was 1:2.6. The average pre-operative serum calcium and PTH levels were 11.6 +/- 0.9 mg/dL and 310.9 +/-305 pg/ml, respectively. 134 out of 138 patients with preoperative PTH US had images available for review by investigators. Compared to the pre-operative read that identified 106 lesions, 19 additional parathyroid lesions were identified: seven (36.8%) were easily identifiable lesions with typical US features, 3 (15.8%) were easily identifiable lesions with atypical US features, 5 (26.3%) were lesions adherent to the thyroid gland and 9 (47.4%) were small lesions that were likely only identified by the investigators due to knowledge of the final pathology and intraoperative findings. Forty-seven parathyroid lesions could not be identified by investigators and one or more of the following reasons were determined as possible explanations: lesion was small in size (14.9%), presence of a large thyroid gland (27.7%), location of the lesion deep in the neck or at an ectopic location (21.3%). The quality of stored images was inadequate in 31.9% of these cases. After review, 67.1% (compared to the actual detection rate of 61.3%) of parathyroid lesions should have been identified on preoperative US. Sixty percent of parathyroid lesions were left sided and 66.9% were inferior in location. The shapes observed were oval (48.8%), conforming (50.4%) or elongated (<1%) and echogenicity was hypoechoic (86.8%) or isoechoic (13.2%). Only a small percentage had a target sign (6.6%) or were partially cystic (7.4%). 74.8% demonstrated a feeding vessel and 33.6% had vascular arborization or scattered vascularity. Conclusions: While parathyroid lesions with typical US feature and locations are easily identified, the common reasons for failure to identify a lesion include atypical features, small size, slender configuration and adherence to the thyroid gland. Being aware of these possibilities can improve detection rate. Parathyroid lesions are also less likely to be identified when present deep in the neck or at an ectopic location outside of the neck.

Characteristic muscle signatures assessed by quantitative MRI in patients with Bethlem myopathy.

Using MRI, the main aim was to (1) map the pattern of muscle involvement by assessing fat fraction and (2) investigate frequency of target and sandwich signs in 42 muscles of patients with Bethlem myopathy (BM). Fifteen BM patients were included. Results were compared to findings in 8 healthy controls and 50 patients with four other types of muscular dystrophies. All muscles, except one, showed higher fat fraction in BM patients vs healthy controls (p < 0.05) with an overall proximal muscle affection, resembling a limb girdle-like pattern. In moderate patients, the specificity was 90% for the sandwich sign and 98% for the target sign. Sensitivity for both signs was 100%. Twelve BM patients had sandwich sign in other muscles than the vastus lateralis. Muscle strength correlated with fat fraction. Mean fat fraction in the psoas major was 39% in BM patients, which was considerably higher than in 3 of the 4 muscular dystrophy control diseases. The presence of signs in conjunction with severe affection of the psoas major muscle can serve as a diagnostic tool in BM. The high level of STIR lesions in muscles of BM patients warrants further investigations.

Target Sign of Third Ventricle in Basilar Dolichoectasia with Multiple Clinical Presentations: A Case Report

AbstractBasilar dolichoectasia (BDE) is an uncommon anatomical variant usually detected incidentally or during stroke evaluation. BDE can occasionally become symptomatic and may present with stroke (infarct or hemorrhage), raised intracranial pressure due to obstructive hydrocephalus, or with cranial nerve palsies. We present a unique case of BDE presenting with obstructive hydrocephalus, stroke, and cranial nerve palsy in single patient and propose a radiological sign (target sign of third ventricle), which could aid in imaging diagnosis and further management.

Analysis of whole-body bone scintigraphy and SPECT/CT imaging in osteoid osteoma

Objective To analyze features of osteoid osteoma on whole-body bone scan (WBS) and SPECT/CT imaging. Methods From January 2010 to December 2018, 70 patients (50 males, 20 females, age: 4-66 years) with osteoid osteoma confirmed by pathology were enrolled from the Affiliated Hospital of Southwest Medical University. All patients underwent WBS and SPECT/CT imaging and imaging features were retrospectively analyzed. Results A total of 70 lesions were found by WBS combined with SPECT/CT imaging, and 26 lesions (37.1%, 26/70) were found in the femur and 25 lesions (35.7%, 25/70) in the tibia. The radioactive ratio of target lesion to non-target lesion (T/NT) was 3.7±1.2 in 56 patients who underwent three-phase bone imaging. WBS showed that 48 lesions (68.6%, 48/70) were round (or nearly round), 21 lesions (30%, 21/70) were spindle-shaped, and 1 lesion (1.4%, 1/70) was irregular-shaped, while SPECT/CT imaging showed that 69 lesions (98.6%, 69/70) were round (or round) and 1 lesion (1.4%, 1/70) was irregular-shaped. The double-density sign was found in 48 lesions (68.6%, 48/70) by WBS and in 59 lesions (84.3%, 59/70) by SPECT/CT imaging. SPECT/CT imaging detected nidus in 59 lesions (84.3%, 59/70) and calcification or ossification ( target sign ) in 27 lesions (38.6%, 27/70). Conclusion The typical features of osteoid osteoma on WBS and SPECT/CT imaging include double density sign , nidus and target sign , which contribute to the diagnosis of osteoid osteoma. Key words: Osteoma, osteoid; Radionuclide imaging; Tomography, emission-computed, single-photon; Tomography, X-ray computed; Technetium Tc 99m medronate

Intramuscular peripheral nerve sheath tumors: schwannoma, ancient schwannoma, and neurofibroma.

To analyze the prevalence of classic magnetic resonance imaging (MRI) findings of intramuscular peripheral nerve sheath tumors (PNSTs), including schwannoma, ancient schwannoma, and neurofibroma. Thirty pathologically confirmed benign intramuscular PNSTs (24 schwannomas, 3 ancient schwannomas, and 3 neurofibromas) were retrospectively reviewed. Classic MRI findings of PNSTs including split fat sign, fascicular sign, target sign, entering and exiting nerve, and thin hyperintense rim were assessed for each intramuscular PNST. Denervation change of the affected muscle was also assessed. In ancient schwannoma and neurofibroma, the signal intensity (SI) and enhancement pattern were analyzed. All intramuscular schwannomas revealed two more classic MRI findings. Eight of the 24 intramuscular schwannomas revealed affected muscle denervation change. All intramuscular ancient schwannomas showed only split fat sign. All intramuscular ancient schwannomas showed denervation change of the associated muscle. All intramuscular neurofibroma showed split fat sign and one case with target sign was detected. Ancient schwannomas were isointense SI on T1-weighted image (T1WI) and one case had hyperintense foci. They showed heterogeneously hyperintense SI on T2-weighted image (T2WI) with heterogeneous enhancement. Neurofibromas were isointense SI (2/3) and slight hyperintense SI (1/3) on T1WI and heterogeneously hyperintense SI on T2WI with heterogeneous enhancement. One ancient schwannoma showed conglomerated calcifications. Intramuscular schwannomas were easily diagnosed based on MRI. In the case of intramuscular ancient schwannoma and neurofibroma with only split fat sign among the classic MRI findings, they might be distinguished from other intramuscular soft tissue tumors based on muscle denervation change or typical crescent split fat sign.

MRI findings of an atypical testicular epidermoid cyst

Introduction:Typical testicular epidermoid cysts (TECs) manifestate as a target sign or onion skin sign on ultrasonography and magnetic resonance (MR) imaging. Clinicians are increasingly aware of the imaging characteristics of typical TECs, which allow accurate diagnosis and successful treatment while preserving the testicle, but atypical TECs are likely to be misdiagnosed as a malignant intratesticular neoplasm, leading to complete testicular resection.Patient concerns:A 26 year-old male patient complained of a painless enlargement of the left testicle that had been present for 1 month. The patient had no recent medical history of scrotal trauma or systemic infection.Diagnosis:A round 48 mm × 45 mm × 43 mm mass was seen inside the left testicle. T2-weighted images of the lesion showed a thin hypointense capsule. T1-weighted images of the lesion showed a hyperintense nodule on the cyst wall, which appeared hypointense on T2-weighted and SPAIR images. After Gd-DTPA injection, the lesion was not enhanced; however, the nodule was enhanced on THRIVE images. These manifestations were consistent with a benign intratesticular lesion, and MR imaging diagnosed atypical TEC, which was confirmed by pathology after surgery.Interventions:The patient was treated with organ-sparing surgery with testicular enucleation.Outcomes:The patient was re-examined with ultrasonography 3 months after surgery. The left residual testicular tissue appeared normal, and reproductive function was preserved.Conclusion:Urologists must be aware of the clinical and MR imaging characteristics of atypical TECs and the utility of preoperative MR imaging for the diagnosis of testicular lesions to ensure that organ-sparing surgery is performed rather than unnecessary orchiectomy.

Chest CT target sign in a couple with COVID-19 pneumonia.

We describe a target sign on chest CT characterized by a combination of peripheral ring-like opacity and a central nodular ground-glass opacity surrounding a vessel in a couple with COVID-19 pneumonia confirmed by real-time reverse transcriptase fluorescence polymerase chain reaction sputum analysis.

Breast schwannoma – a rare entity

Introduction: Schwannoma is a benign tumor originating from Schwann cells present in the myelin sheath of peripheral nerves. Breast presentation is rare, and its clinical manifestation can mimic that of breast carcinoma. Objectives: To report the case of a patient with breast Schwannoma. Method/Case report: T.S.L., 14 years old, presented a nodule in the left breast (LB) with local growth for 2 months. Ultrasound (US) revealed a cystic formation in the lower outer quadrant of 1.8x1.3 cm, BI-RADS 2. Physical examination indicated a nodular skin lesion next to the LB fold, with 2 cm at 5 h, 7 cm from the nipple. After the surgical excision of the nodule, anatomopathological examination showed a spindle cell neoplasm without nodular-pattern atypia or malignancy characteristics. Immunohistochemistry (IHC) confirmed the Schwannoma diagnosis. Considering this scenario, annual control was started, and the patient has no evidence of the disease after 5 years of diagnosis. Results/Discussion: Schwannoma is a typically benign tumor originating from Schwann cells in the myelin sheath of the nerves. It may result from the parasympathetic or sympathetic division of the autonomic nervous system of the organ. It is one of the few truly encapsulated tumors of the human body and almost always solitary. It is usually located in the trunk, flexor surfaces, retroperitoneum, and rarely in the breast, representing approximately 2.6% of Schwannoma cases. It affects individuals aged 30 to 50 years, with equal incidence in both men and women. The skin lesion presents as a sessile, asymptomatic nodule of 1–3 cm and slow growth. Pain and sensitivity may be present when tumor growth causes nerve compression. Mammography (MMG) shows well-circumscribed opacity, with a density similar to that of soft tissue. US usually reveals well-defined, hypoechoic, solid lesions and can include the target sign, posterior acoustic enhancement, and continuity with peripheral nerves. The definitive diagnosis is made histologically, and the differential diagnosis involves other spindle cell neoplasms, such as fibroadenoma, phyllodes tumor, leiomyoma, fibromatosis, and, rarely, metaplastic carcinoma. Fine-needle aspiration biopsy (FNAB) showed palisading fibrillar cells with non-atypical spindle-shaped nuclei forming Verocay bodies. IHC indicates intense and uniform expression of S-100 protein. Malignant transformation occurs in 3–10% of cases, with high cellular proliferation, atypical mitotic activity, cellular and nuclear pleomorphism, and foci of necrosis. The treatment of choice is surgical excision of the lesion. Tumor recurrence is low and associated with the mitotic index. Conclusion: The case reported and publications found bring to light the discussion on diagnosis and treatment of breast Schwannoma, a rare and benign neoplasm in this location.

Será o sinal do alvo um achado tomográfico específico de pneumonia por COVID-19?

Será o sinal do alvo um achado tomográfico específico de pneumonia por COVID-19?

2594 An Unusual Case of Small Bowel Intussusception

INTRODUCTION: Intussusception is the telescoping of a part of the intestine into a more distal segment. The first case of intussusception was reported in 1674 by Barbette and detailed in 1789 by John Hunter. It is often classified by location into entero-enteric (65%), Ileocecal (19%), Colo-colic (9%) and finally duodeno-duodenal (&lt;5%). It typically presents between the age of 6 and 36 months making adult presentation rare. We report a rare case of Duodeno-duodenaI intussusception secondary to tubular adenoma. CASE DESCRIPTION/METHODS: A 57 year old African American female with a history of rheumatoid arthritis and hysterectomy presents to the emergency room with complaints of epigastric pain for two days. The pain was intermittent, aggravated by food, and associated with nausea and two episodes of vomiting. She denies any other symptoms or similar episodes in the past. Last bowel movement was reported a day prior to presentation. Vital signs upon admission were within normal limits. On physical examination abdomen was soft, non distended with epigastric tenderness. Blood work on admission was unremarkable except for White blood cell count of 11.6 k/ul and Lactate level of 1.6 mmol/L. Computer Tomography (CT) scan of Abdomen showed telescoping of the apparent 2nd and 3rd portions of the duodenum compatible with intussusception (Figure 1). Patient underwent upper endoscopy with biopsies that showed a 3 cm duodenal polypoid lesion with pathology revealing tubular adenoma (Figures 2 and 3). Patient's symptoms resolved 2 day after presentation with supportive care only. Patient underwent endoscopic submucosal dissection of the lesion. DISCUSSION: Adult small bowel intussusception is a very rare entity that accounts for 5% of all cases of intussusception and 1%-5% of intestinal obstructions. The diagnosis can be challenging as symptoms are nonspecific and includes abdominal pain, nausea and vomiting. CT scan was found to be the preferred imaging study with specificity of 100% and sensitivity of up to 87% in adults. It often shows a “target sign” on the sagittal view or a sausage-shaped mass on axial and coronal views. It is always associated with a lead point such as a lipoma, hamartomatous polyps. The etiology in our case was a tubular adenoma which makes it more intriguing. Although duodenal intussusception is rare, recognition is critical for institution of appropriate therapy and prevention of complications. It should be considered in the differential diagnosis of any abdominal pain with signs of bowel obstruction.