Objective:To study the CT manifestations of malignant hepatic perivascular epithelioid cell carcinoma (PEComa).Methods:Clinical data of nine patients undergoing surgery with histologically confirmed malignant hepatic PEComa in Yueqing People's Hospital, Wenzhou People's Hospital, and Yongjia County People's Hospital from January, 2010 to June, 2022 were retrospectively collected, including two males and seven females with a median age of 47 (43, 56) years old. The CT findings, including tumor size, shape, boundary, density, and enhancement patterns, were analyzed.Results:CT scans showed that all nine tumors were single lesions. Five tumors were located in right liver lobe, three in left lobe, and one in caudate lobe. The median tumor diameter was 5.7 (range, 3.3-16.0 ) cm. In terms of tumor shape, three were round, four were quasi-circular, and two were irregular. Eight tumors had well-defined boundaries, while one was ill-defined. Nine tumors showed uneven densities and were lower than the adjacent liver parenchyma. Four tumors had a false capsule, one contained fatty tissue, and six had necrotic and cystic changes. In the arterial phase of contrast-enhanced CT scanning, two tumors showed moderate enhancement and seven showed significant enhancement. In the portal venous and delayed phases, enhancement decreased significantly in four cases, showing a " fast-in and fast-out" pattern. In four cases, the enhancement persisted, showing a " fast-in and slow-out" pattern. One case showed no enhancement in any phase but had a strip-like enhanced vessel inside the tumor. Five cases had significantly thickened vessels around the tumor.Conclusion:The CT manifestations of PEComa are as follows: round or quasi-circular lesions with well-defined boundaries, uneven low densities, significant enhancement in the arterial phase and rapid washout or persistent enhancement in the portal venous and delayed phases.

Objective:To investigate the characteristics of computed tomography(CT) and magnetic resonance imaging(MRI)of focal peliosis hepatis (PH).Methods:From January 1, 2015 to December 31, 2022, a total of 8 PH patients (10 lesions) diagnosed pathologically in Yueqing People′s Hospital were collected. The location, size, and shape of the lesions, as well as the CT (4 patients with 4 lesions) and MRI (5 patients with 7 lesions) characteristics of the patients were analyzed. Descriptive method was used for statistical analysis.Results:Among the 8 PH patients, 6 patients had lesions located in the right lobe of the liver, 1 in the left lobe of the liver, and 1 (3 lesions) in both left and right lobes of the liver. Eight lesions were round or round-like, and 2 lesions were irregularly shaped. The median maximum diameter of the lesions was 4.2 cm (ranged from 2.2 to 9.3 cm), of which the maximum diameters of 2 lesions were less than 3.0 cm, those of 6 lesions were 3.1 to 5.0 cm, and those of 2 lesions were more than 6.0 cm. Nine lesions had clear boundaries, and 1 lesion had blurred boundary; 9 lesions had capsule, 1 lesion had no capsule; 1 lesion had blood vessels passing through it. The CT plain scan of 4 patients (4 lesions) showed that 3 lesions had uniform density and 3 lesions had low density, the CT enhancement showed that 2 lesions were significantly enhanced in the arterial phase, 3 lesions were sustained moderately enhanced in the portal phase, and 2 lesions were sustained mildly enhanced in the delayed phase. The MRI plain scan of 5 patients (7 lesions) showed uniform signals in 6 lesions, low signal in 3 lesions and equal signal in 4 lesions on T1-weighted images, high signal in 6 lesions on T2-weighted images, high signal in 3 lesions and equal signal in 4 lesions on diffusion-weighted images. The MRI enhancement showed that 4 lesions were significantly enhanced in the arterial phase, 5 lesions were sustained moderately enhanced in the portal phase, and 6 lesions showed sustained mild enhanced in the delayed phase.Conclusion:The PH lesions are round or round-like, with clear or unclear boundaries and uniform or uneven density, and are characterised by low density on CT and MRI plain scan, low signal on T1-weighted images, and high signal on T2-weighted images and diffusion-weighted images, and moderate or significant sustained enhancement on CT and MRI enhancement.

Objective:To investigate the magnetic resonance imaging (MRI) features of desmoplastic small round cell tumor (DSRCT) of the abdomen and pelvis.Method:The retrospec-tive and descriptive study was conducted. The clinicopathological data of 8 patients with DSRCT of the abdomen and pelvis, including 3 cases admitted in Yueqing People's Hospital and 5 cases admitted in Wenzhou People's Hospital, from January 2008 to June 2022 were collected. There were 5 males and 3 females, aged (43±5)years. All patients underwent MRI plain and enhanced scanning. Observa-tion indicators: (1) imaging features of DSRCT of the abdomen and pelvis; (2) treatment and pathological examination characteristics of DSRCT of the abdomen and pelvis; (3) follow-up. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distri-bution were represented as M(range). Count data were described as absolute numbers. Results:(1) Imaging features of DSRCT of the abdomen and pelvis. ① Tumor location. Of the 8 patients, there were 6 cases with tumors located respectively at the lower edge of the liver in the right quarter costal region, the medial side of the ileocecal region in the right iliac region, the medial side of the caecum in the right iliac region, the gastro-pancreatic space in the left quarter costal region, the mesenteric space in the left iliac region and the right side of pelvic bladder, and 2 cases with tumors located at retroperitoneal space of left quarter rib region. ② Tumor size. There were 13 lesions in the 8 patients, and the maximum diameter of tumor was 9.1 (range, 3.5?20.0)cm. Of the 8 patients, there were 5 cases with single tumor and 3 cases with multiple tumors. ③ Tumor shape and boundary. Of the 8 patients, there were 4 cases with tumor in expansive growth and 4 cases with tumor in invasive growth. There were 5 cases with tumor of intratumoral necrosis and cystic degene-ration, 4 cases with tumor of intratumoral hemorrhage, 4 cases with tumor of intratumoral spot calcification, 3 cases with tumor of peritumoral tissue exudation. One patient may combined with multiple imaging manifestations. ④ Imaging characteristics of MRI plain scanning. Of the 8 patients, there were 4 cases with tumor of homogeneous hypointensity signal and 4 cases with tumor of hypointensity mixed with speckled hyperintensity (with hemorrhage) in T1 weighted imaging of MRI plain scanning. There were 3 cases with tumor of homogeneous hyperintensity and 5 cases with tumor of high signal at the edge, patchy and spot-shaped in the center in T2 weighted imaging of MRI plain scanning. There were 5 cases with tumor of high, equal and low confounding signals and 3 cases with tumor of high and low signals in T2 weighted imaging fat suppression sequence of MRI plain scanning. There were 3 cases with tumor of uniform high signals and 5 cases with tumor of high, equal and low mixed signals in diffusion weighted imaging of MRI plain scanning. ⑤ Imaging characteristics of MRI enhanced scanning. All 8 patients had tumor of heterogeneous enhancement in MRI enhanced scanning, including 2 cases with significant enhancement in arterial phase, continuous enhancement in portal phase, slightly reduced enhancement in delayed phase, 4 cases with moderate enhancement in arterial phase, continuous enhancement in portal phase, slowly exited enhancement in delayed phase, 2 cases with mild enhancement in arterial phase, continuous enhancement in portal phase, slowly exited enhancement in delayed phase. Of the 8 patients, there were 3 cases with tumor of annular enhancement with intratumoral strip or grid signals and 3 cases with tumor of peritumoral blood vessels increased and thickened signals. ⑥ Tumor invasion and metastasis. Of the 8 patients, there were 4 cases with tumor invaded bowel, 2 cases with tumor invaded surrounding tissues, 1 case with tumor invaded left kidney, spleen and pancreatic tail, 1 case with tumor invaded distal of left ureter. There were 5 cases with abdominal, retroperitoneal and inguinal lymph nodes enlargement, 4 cases with multiple nodular thickening of peritoneum and ascites, 2 cases with tumor liver and lung metastasis and 1 case with tumor rib, femur and sacrum metastasis. One patient may combined with multiple tumor metastasis. (2) Treatment and patholo-gical examination characteristics of DSRCT of the abdomen and pelvis. Of the 8 patients, 3 patients underwent complete resection as clear tumor boundary, 3 patients underwent tumor partial resection as tight adhesion between tumor and surrounding blood vessels, 2 cases underwent tumor tissue pathological examination as extensive metastasis of peritoneum, omentum, mesentery and surrounding intestine. All 8 patients were diagnosed as DSRCT by microscopic examination, electron microscopic examination, immunohistochemical staining and cytogenetic examination. (3) Follow-up. All 8 patients underwent postoperative follow-up and died during the follow-up.Conclusion:MRI features of abdominal and pelvic DSRCT include single or multiple lobulated masses with unclear boundaries, invading the omentum, mesentery, peritoneum and adjacent tissues in most cases, mixed signals and heterogeneous mild to moderate enhancement in enhanced scanning.

Objective:To explore the CT features of inflammatory pseudotumor like follicular dendritic cell sarcoma (FDCS) of the spleen.Methods:The clinical data of 12 patients with splenic inflammatory pseudotumor like FDCS admitted to 3 central hospitals including Yongjia People's Hospital in Zhejiang Province from January 2015 to December 2022 were retrospectively analyzed, including 4 males and 8 females, with a median age of 60 years old. The number, shape, size and CT features of the lesions were analyzed based on patient's CT image data.Results:CT scans of 12 patients showed 15 lesions, including 10 single lesions and 2 multiple lesions. The lesions were circular in 5 cases, elliptical in 4 cases, and irregular in 3 cases. The median maximum diameter of the mass is 6.5 cm. On plain scan, all 12 tumors showed low density or slightly low density. The CT value is (41.3±7.2) HU; 8 cases had uneven density and 4 cases had uniform density. There were 8 cases with clear tumor boundaries and 4 cases with unclear boundaries. There were 8 cases with tumor necrosis and cystic transformation, and 5 cases showed patchy bleeding lesions in the center of the tumor. Enhancement: the arterial phase shows small patches or flocculent enhancement at the edges or parenchymal parts of the tumor, with CT value of (56.0±3.8) HU. Among them, there were 7 cases of mild enhancement, 4 cases of moderate enhancement, and 1 case of significant enhancement. During the portal phase, there was mild to moderate persistent small patchy uneven enhancement, with CT value of (62.0±4.3) HU. Among them, there were 8 cases of mild enhancement and 4 cases of moderate enhancement. The delayed phase showed a slow withdrawal of enhancement, with CT value of (45.0±8.2) HU. All 12 cases underwent complete resection and were diagnosed with FDCS through pathological examination.Conclusion:FDCS plain scan shows circular or elliptical uneven low-density masses, with small patches or flocculent light to moderate uneven enhancement in the arterial phase, continuous enhancement in the portal phase, and slow withdrawal in the delayed phase as the main characteristics.

Objective:To explore the imaging features of hyperostosis frontalis interna (HFI).Methods:One hundred patients with clinically diagnosed HFI were enrolled from Department of Radiology, Yueqing People's Hospital and Department of Imaging, Wenzhou People's Hospital from January 2011 to December 2022. MRI alone was performed in 45 patients; MRI+DR was performed in 14, and MRI+CT was performed in 41. The imaging features of these patients were analyzed retrospectively.Results:In these 100 patients, 20 were with external hyperplasia, 51 with internal hyperplasia, and 29 with intermediate hyperplasia. External hyperplasia manifested as proliferating towards the diploe, enjoying clear boundary, uniform high signals of the hyperplastic inner plate and diploe on T1WI and T2WI, and high density of the hyperplastic inner plate and diploe on CT and DR. Internal hyperplasia manifested as proliferating towards the cranial cavity, enjoying wavy or nodular inner edges, non-uniform low signals of hyperplastic inner plate on T1WI and T2WI, and high density of the hyperplastic inner plate on CT and DR. Intermediate hyperplasia manifested as proliferating simultaneously towards the cranial cavity and diploe, enjoying thin and blurred diploe, uniform or non-uniform high signals of the hyperplastic inner plate and diploe on T1WI and T2WI, and non-uniform high density of the hyperplastic inner plate and diploe on CT and DR. Compressed and displaced brain parenchyma, reduced anterior cranial fossa volume, and narrowed subarachnoid space were noted in these 100 patients, including 47 patients with obvious frontal lobe brain tissue compression (depth of 3.0-17 mm, averaged [8.6±5.9] mm), 35 with lacunar cerebral infarction, 33 with subcortical arteriosclerotic encephalopathy, and 32 with varied degrees of cerebral atrophy.Conclusion:HFI is characterized by thickening and hardening of the bilateral frontal bone inner plates, with wavy, nodular or spindle-shaped inner edges, compressed brain tissues, and reduced anterior cranial fossa; these imaging features can help the definite diagnosis of HFI.

The patient, a 61-year-old female, was admitted to the hospital for 15 days of frequent urination, urgency, painful urination and hematuria. B-ultrasound showed irregular hypoechoic masses on the anterior wall of the bladder. CT showed that the right anterior wall of the bladder protruded into the cavity of the soft tissue mass, which was lobulated, and the edge of the mass showed arc-shaped calcification; enhancement shows that the mass continues to enhance. Cystoscopy showed a lobulated soft tissue mass protruding into the cavity on the right anterior wall of the bladder, and cystoscopy showed tumor-like lesions. The preoperative clinical and imaging diagnosis was a malignant tumor of the bladder. Open partial resection of the right anterior wall of the bladder under general anesthesia, and pathological diagnosis of bladder leiomyosarcoma after surgery. Adjuvant chemotherapy (gemcitabine 1.6 g + epirubicin 80 mg + cisplatin 30 mg) was started 2 months after the operation. The chemotherapy was discontinued after a year, and the patient had no obvious adverse reactions. There were no signs of recurrence and metastasis after a 2-year follow-up.

Objective:To investigate the computed tomography (CT) features of primary hepatic fibrosarcoma (PHF).Methods:The retrospective and descriptive study was conducted. The clinicopathological data of 8 patients with PHF who were admitted to 2 medical centers from January 2010 to December 2019, including 3 cases of Yueqing People's Hospital of Zhejiang and 5 cases of Wenzhou People's Hospital of Zhejiang were collected. There were 5 males and 3 females, aged 50 years(range, 39?60 years). All patients underwent abdominal CT plain and enhanced examination, and surgical procedures were selected based on patients' will and individual situations. Surgical tumor specimens were given pathological examination and immunohistochemical staining. Observation indicators: (1) imaging features of CT examination; (2) treatment and pathological examinations; (3) follow-up. Follow-up was performed by outpatient examination or hospitalization to detect survival of patients and tumor recurrence up to December 2020. Measurement data with skewed distribution were represented as M(range). Count data were described as absolute numbers. Results:(1) Imaging features of CT examination: 8 patients received preoperative CT examinations, 3 cases of which were diagnosed as malignancies, 3 cases were diagnosed as hepatic space-occupying lesions, 2 cases were diagnosed as intrahepatic cholangiocarcinoma. ① Tumor location and general status: 8 patients had single tumor, of which 6 cases had tumor located in the right lobe of the liver and 2 cases had tumor located in the left lobe of the liver. The tumor was in oval shape in 5 patients and in circular in 3 patients. The maximum diameter of tumor in 8 patients was 9.3 cm(range, 4.0?15.0 cm). There were 1 case with tumor maximum diameter ≤5.0 cm, 4 cases with tumor maximum diameter as 5.1?10.0 cm, 3 cases with tumor maximum diameter >10.0 cm. ② CT plain scan showed uniform low density in 2 cases and uneven low density in 6 cases and the CT value of 8 cases was 40 HU(range, 29?43 HU). The tumor showed expansive growth with clear boundary in 6 cases, and invasive growth with unclear boundary in 2 cases. Five cases had intratumoral necrosis and cystic transformation, 2 cases had intratumoral strip hemorrhage, and 1 case of intratumoral calcification. There was 1 case with hilar lymph node metastasis. ③ Enhanced CT scan showed 8 cases with uneven enhancement in arterial phase, 8 cases with uneven tumor density in portal vein phase, 8 cases with intratumoral enhancement slowly withdrew in delayed phase and the density lower than liver parenchyma. (2) Treatment and pathological examinations: ① 8 patients under-went surgical resection, without intrahepatic or hilar metastasis. ② The results of postoperative pathological examination showed 2 cases with grade Ⅰ tumor differentiation (low potential malignancy), 5 cases with grade Ⅱ and Ⅲ tumor differentiation (moderate potential malignancy), 1 case with grade Ⅳ tumor differentiation (high potential malignancy). ③ Immuno-histochemical staining showed that 8 cases were positive for vimentin, CD10, p53 and negative for smooth muscle actin, keratin19, epithelial membrane antigen, endotheliocyte 34. All 8 patients were diagnosed as PHF. (3) Follow-up: all 8 patients were followed up for 7 to 128 months, with a median follow-up time of 53 months. The overall survival time of 8 patients was 15 to 122 months, and the median overall survival time was 45 months. One patient died of tumor recurrence and distant metastasis at 17 months after surgery, and the survival time of 7 patients was >28 months.Conclusions:CT plain scan of PHF showed uneven low-density masses. After enhancement, the arterial phase shows the tumor ring or peripheral nodular uneven enhancement, the intratumoral strip-shaped enhanced blood vessels. The portal vein phase shows the tumor-like small patches or grid-like continuous enhancement. The delayed phase is characterized by the slow withdrawal of intratumoral enhancement.

Objective:To investigate the CT and MRI features of meningiomas of the skull.Methods:A retrospective analysis was performed; the CT and MRI findings of 20 patients with meningiomas of the skull confirmed by pathology after surgery in our hospital from January 2008 to December 2020 were collected.Results:Fourteen patients had skull osteolytic destruction, 4 had osteogenic destruction, and 2 had mixed destruction. There were 12 patients with soft tissue masses and 11 with radial spicules. In 16 patients accepted CT examination, uniform density was noted in 10 and uneven density in 6; 8 had high density, 5 had equal density, and 3 had low density; 5 patients were with calcification. In 17 patients accepted MRI examination, 11 had uniform signal and 6 had un-uniform signal; T1WI had slightly low signal in 12 patients and equal signal in 5 patients; T2WI had slightly high signal in 12 patients and slightly low signal in 5 patients; diffusion weighted imaging (DWI) had high signal in 12 patients and slightly high signal in 5 patients. Totally, enhanced homogeneous enhancement was noted in 12 patients and inhomogeneous enhancement was noted in 8 patients; and there were 13 patients with "meningeal tail sign" and 11 with peritumoral edema.Conclusion:Bone in patients with meningiomas of the skull is characterized by osteolytic or osteogenic destruction with soft tissue masses and radial spicules; CT shows uniform or un-uniform tumor density, MRI shows uniform or un-uniform signals, and enhanced "meningeal tail sign" is characterized.

Objective: To investigate the imaging features of adult bones Langerhans cell histiocytosis (LCH). Methods: The DR, CT, and MRI findings of 25 adults patients with LCH from January 2008 to June 2019 in Yueqing Sixth People′s Hospital of Zhejiang Province (3 cases), Yueqing Third People′s Hospital of Zhejiang Province (7 cases) and Wenzhou People′s Hospital of Zhejiang Province (15 cases) were retrospectively analyzed. Results: Among the 25 patients, the lesions located in the skull in 5 cases, in the spine in 5 cases, in the long bones in 10 cases, in the other flat bones in 3 cases, and in multiple bones in 2 cases. DR features (17 cases) showed: cystic destruction in 11 cases (6 cases with dilated changes), osteolytic damage in 6 cases; peripheral bone cortex thickening in 5 cases, bone lesions with less smooth inner edge in 4 cases, soft tissue mass around the lesion in 12 cases; 'hole set cave sign' in 2 cases, 'flat vertebra' in 2 cases, and 'button-like dead bone' in 1 case. CT features (15 cases) showed: cystic destruction in 9 cases (5 cases with dilated changes), osteolytic damage in 6 cases; 'hole set cave sign' in 2 cases, 'flat vertebra' in 2 cases, and 'button-like dead bone' in 1 case. MRI features (14 cases) showed: cystic destruction in 9 cases (5 cases with dilated changes), osteolytic damage in 5 cases; in the bone destruction area, 8 cases had low T₁WI signal and high T₂WI signal, 4 cases had equal T₁WI signal and higher mixed T₂WI signal, 2 cases had slightly higher T₁WI signal and higher mixed T₂WI signal; STIR lipoprotein sequence showed high signal in 11 cases, and isointense signal in 3 cases; DWI showed high signal. Conclusions The imaging performance of adults LCH has certain characteristics, and the diagnostic accuracy can be improved according to the imaging performance and the clinic.

Objective:To summarize the imaging and pathological features of primary central nervous system lymphoma in special sites, and analyze some misdiagnosed cases to provide help for clinical diagnosis.Methods:Thirty-nine patients with primary central nervous system lymphoma diagnosed by pathology from 2000 to 2019 in Wenzhou People′s Hospital and the Second Affiliated Hospital of Wenzhou Medical University were retrospectively analyzed. The imaging and pathological features of primary central nervous system lymphoma in special sites were summarized, and the misdiagnosed cases in these special sites were analyzed.Results:Primary central nervous system lymphoma in special sites included one case of primary dural lymphoma, with thickening of dura mater and obvious enhancement; two cases with lesions in lateral ventricle, with homogeneous enhancement, involving ependyma and spreading to medulla oblongata; two cases with lesions in middle cerebellar peduncle, with patchy abnormal signals and no specific masses, mild to moderate enhancement after enhancement, and one misdiagnosed as demyelinating lesions; one case with lesions in the sellar region which obviously enhanced with a typical “dent sign”, misdiagnosed as invasive pituitary tumor. All the pathological findings indicated diffuse large B cell lymphoma.Conclusions:It is difficult to diagnose primary central nervous system lymphoma in special sites, which is easy to cause misdiagnosis. Understanding its imaging characteristics and pathology can help to diagnose the disease.