Neuroendocrine carcinoma of the urinary bladder: a retrospective study of CT findings

CT and MRI findings of small cell neuroendocrine carcinoma of the urinary bladder: comparison with urothelial carcinoma

OBJECTIVE

This study aimed to evaluate the efficacy of CT and MRI findings to differentiate small cell neuroendocrine carcinoma (SCNEC) from urothelial carcinoma (UC) of the urinary bladder.

MATERIALS AND METHODS

This study included 90 patients with histopathologically confirmed bladder cancer (10 SCNECs and 80 UCs). Eight patients with bladder SCNEC and 80 with UC underwent CT and MRI, whereas the remaining two patients with SCNEC underwent CT alone before treatment. CT and MRI findings were retrospectively evaluated and compared between the two pathologies.

RESULTS

The maximum diameter (36.5 mm vs. 19.0 mm, p < 0.01) and height (22.0 mm vs. 14.0 mm, p < 0.01) of the tumor in bladder SCNEC were higher than in UC. The pedunculated configuration (20% vs. 61%, p < 0.05) and irregular tumor margins (20% vs. 76%, p < 0.01) in bladder SCNEC were less common than in UC. The CT attenuation of the solid component in unenhanced CT images was higher in bladder SCNEC than in UC (37 Hounsfield unit [HU] vs. 34 HU, p < 0.01). The apparent diffusion coefficient (ADC) of the solid component in bladder SCNEC was lower than in UC (0.49 × 10-3 mm2/s vs. 1.02 × 10-3 mm2/s, p < 0.01).

CONCLUSION

In comparison with UC, bladder SCNEC was larger, had higher unenhanced CT attenuation, and had a lower ADC value. The pedunculated configuration and irregular tumor margins were typical of bladder UC.

Neuroendocrine Carcinoma of the Urinary Bladder: CT Findings and Radiomics Signature

Background: We present a case series of Neuroendocrine Carcinoma of the Urinary Bladder (NECB) to analyse their radiologic appearance on CT, find a "Radiomic signature", and review the current literature. Methods: 14 CT cases of NECB were reviewed and compared with a control group of 42 patients with high-grade non-neuroendocrine bladder neoplasm for the following parameters: ring enhancement; implantation site; dimensions; density; margins; central necrosis; calcifications; number of lesions; wall thickness; depth of invasion in the soft tissue; invasion of fat tissue; invasion of adjacent organs; lymph-node involvement; abdominal organ metastasis. To extract radiomic features, volumes of interest of bladder lesions were manually delineated on the portal-venous phase. The radiomic features of the two groups were identified and compared. Results: Statistical differences among NECB and control group were found in the prevalence of male sex (100% vs. 69.0%), hydronephrosis (71.4% vs. 33.3%), mean density of the mass (51.01 ± 15.48 vs. 76.27 ± 22.26 HU); product of the maximum diameters on the axial plane (38.1 ± 59.3 vs. 14.44 ± 12.98 cm2) in the control group, trigonal region involvement (78.57% vs. 19.05%). About the radiomic features, Student's t-test showed significant correlation for the variables: "DependenceNonUniformity" (p: 0.048), "JointAverage" (p: 0.013), "LargeAreaLowGrayLevelEmphasis" (p: 0.014), "Maximum2DDiameterColumn" (p: 0.04), "Maximum 2DDiameterSlice" (p: 0.007), "MeanAbsoluteDeviation" (p: 0.021), "BoundingBoxA" (p: 0.022) and "CenterOfMassB" (p: 0.007). Conclusions: There is a typical pattern (male patient, large mass, trigonal area involvement) of NECB presentation on contrast-enhanced CT. Certain morphological characteristics and encouraging results about Radiomic features can help define the diagnosis.

Imaging of neuroendocrine neoplasms of the male GU tract

Male genitourinary neuroendocrine neoplasms (GU-NENs) are rare, without any definite imaging characteristics. The WHO classified neuroendocrine neoplasms in the 2016 classification of the tumors of the urinary tract and genital organs along with other GU tumors; however, no pathologic grading system is available as published for gastroenteropancreatic neuroendocrine neoplasms. Often a multimodality approach using cross-sectional imaging techniques, such as molecular imaging and histopathology are implemented to arrive at the diagnosis. This article provides a review of the pathology and imaging features of the male GU-NENs.

Dynamic FDG PET/CT on bladder paraganglioma: A case report

Paraganglioma (PGL) is characterized by equivocal clinical manifestations and arriving to a suspicion might be challenging. Nevertheless, diagnostic imaging and nuclear medicine are a fundamental part of the diagnosis and management of this particular neuroendocrine tumor (NET). We herein report a rare case of bladder paraganglioma with unusual onset and typical PET/CT characteristics that led to its recognition.

Application of contrast-enhanced ultrasonography for large cell neuroendocrine carcinoma in the urinary bladder: a case report

Background

Large cell neuroendocrine carcinoma (LCNEC) of the urinary bladder is an uncommon malignant bladder tumor, and the overall prognosis is poor. Contrast-enhanced ultrasound (CEUS) provides a new effective modality for tumor detection and diagnosis.

Case presentation

A 30-year-old man complained of repeated painless gross haematuria for half a month. Conventional ultrasound demonstrated a hypoechoic solitary lesion with hyperechoic margins measuring 3.4 × 3.1 cm in the anterior wall of the bladder. Superb microvascular imaging (SMI) showed a strong flow signal in the mass. CEUS revealed that the lesion was characterized by hyper-enhancement in the early phase and hypo-enhancement in the late phase. The entire bladder wall was disrupted by homogeneous hyper-enhanced tumor tissue on CEUS. Time-intensity curves (TICs) showed a rapid wash-in with a high maximum signal intensity (SI) and quick wash-out. Finally, partial cystectomy was performed and the pathological examination confirmed the diagnosis of LCNEC with invasion into the whole layer of the bladder wall.

Conclusion

This case suggested that CEUS was a valuable imaging method to detect and diagnose LCNEC in the bladder, and that CEUS can provide information related to the depth of wall invasion and the microvasculature.