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

Abstract

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 hypoenhancement 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.

Urinary Large Cell Neuroendocrine Carcinoma

“…Fewer than 50 sporadic cases have been reported in the literature so far, including both pure and mixed histology. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] Nevertheless, since this tumor has been recently recognized as a distinct entity, it has been suggested that some urinary LCNECs might have gone underdiagnosed or just misdiagnosed as undifferentiated UC. 7 Similar to lung tumors, underdiagnosis and consequent underreporting remain an issue also in bladder cancer if appropriate diagnostic workup is not performed.…”

“…Similar to SmCC, LCNEC is a biologically aggressive NE tumor, usually associated with a dismal prognosis despite an aggressive treatment. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]34 Most clinical studies have analyzed both SmCCs and LCNECs, the latter comprising a small amount of the whole case series, and reported similar survival and cancer-specific mortality rates in LCNEC compared with SmCC, ranging from <1 year for advanced disease to > 2 years for early disease. 7,12,15,16 Bhatt et al 10 reported a 5-year survival rate of 17% for their study population, which consisted of 14 SmCCs and only 4 LCNECs.…”

“…The overall prevalence of urinary LCNEC seems to be exceedingly low. Fewer than 50 sporadic cases have been reported in the literature so far, including both pure and mixed histology 9–28. Nevertheless, since this tumor has been recently recognized as a distinct entity, it has been suggested that some urinary LCNECs might have gone underdiagnosed or just misdiagnosed as undifferentiated UC 7.…”

“…Current knowledge of this disease is limited and is mainly based on small series and case reports. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] Currently, there is no consensus on standard treatment for patients suffering from this aggressive malignancy. Herein, we describe the largest cohort of LCNEC, providing detailed clinicopathologic and immunohistochemical features of this rare disease.…”

“…Due to the rarity of LCNEC, its biological and clinicopathologic characteristics remain largely unknown, which limits the development and evaluation of rational therapeutic strategies. Current knowledge of this disease is limited and is mainly based on small series and case reports 9–28. Currently, there is no consensus on standard treatment for patients suffering from this aggressive malignancy.…”