Unraveling the characteristics of early esophageal neuroendocrine carcinoma using multi-model endoscopy: A retrospective study of serial cases

Table 1 Clinical data and endoscopic findings of 4 cases with early esophageal neuroendocrine carcinoma

Case	Sex	Age (year)	Presentation	Examination	Location (cm)	Size (cm)
1	Male	60	No symptoms	Tumor markers were normal; contrast-enhanced CT showed no definite mass	30	0.94 × 0.36
2	Male	64	Retrosternal discomfort	Tumor markers were normal; contrast-enhanced CT showed no definite mass	27	1.3 × 0.9
3	Female	70	Recurrent retrosternal discomfort with abdominal distension and chest tightness	Tumor markers were normal; contrast-enhanced CT revealed mild mucosal enhancement in the mid-esophagus and a small nodule in the anterior mediastinum	28	1.2 × 0.7
4	Female	70	Dysphagia	Tumor markers were normal; contrast-enhanced CT showed no definite mass	30	0.5 × 0.6

CT: Computed tomography.

Table 2 Review of all cases of early esophageal neuroendocrine carcinoma

Case	Ref.	Age	Sex	Location	Presentation	NBI	EUS	Stage	Pathology	Treatment	Survival
1	[13]	77	M	Middle	No symptoms	Type B1, type R	The lesion was localized in the mucosa	T1aN0M0	NEC, SCC	ESD, surgery, CTx	No sign of disease recurrence 12 months after surgery
2	[24]	80	M	Middle/28 cm	No symptoms	Type B3, type R	A hypoechoic mass invading the third hyperechoic layer (submucosal layer)	cT1bN0M0/SM2	NEC, SCC	ESD, CTx, RTx	3 months lymph node metastasis; 6 months multiple liver metastases; 8 months died
3	[29]	51	M	25 cm	Dysphagia	NA	NA	T1aN0M0	NEC, squamous cell HGIN	ESD	No recurrence or metastasis 18 months
4	[30]	75	F	Middle	NA	Type B1	A hypoechoic lesion located in the mucosal layer and partially within the superficial submucosal layer	pT1aN0M0	NEC, SCC	ESD, CTx	60 months without any recurrence
5	[31]	49	F	35 cm	Intermittent epigastric soreness and heartburn	NA	A 44 mm × 3.3 mm, well demarcated, homogenous, hypoechoic, round mass lesion within the mucosal layer, and the submucosal layer beneath the lesion was observed to be intact	T1aN0M0	NEC	EMR	2 months alive
6	[32]	55	F	Upper	Intermittent mild dysphagia	NA	Showed that the bulged lesion was highly echoic and homogeneous, originating from the muscularis mucosa	SM2/T1aN0M0	NEC	ESD, CTx	Remained disease-free during a 2-year follow-up
7	[33]	65	M	27 cm	Retrosternal discomfort	NA	Characterized the lesion as an ovoid hypoechoic mass originating from the muscularis mucosae, displaying clear margins and homogeneous echogenicity	T2N1M0	NEC	ESD	Developed systemic metastases after 16 months
8	[34]	54	M	Lower	Dysphagia, dizziness, and melena, GERD	NA	NA	NA	NEC	CTx, surgery	20 months alive
9	[35]	62	M	Distal	Epigastric pain for 2 months; obvious difficulty in swallowing accompanied by chest pain 14 months later	NA	A low echo nodule in the muscularis mucosa, with un-uniform internal echo and a clear boundary. The nodule appeared to have a capsule and the submucosa was smooth and continuous	NA	NEC	CTx, RTx	Developed after 14 months, died of brain metastases 17 months later
	[35]	68	F	NA	Epigastric pain for 1 month	NA	A hypoechoic mass in the muscularis mucosa invading the submucosal layer, and the submucosal layer was thinner than normal but still continuous	T1bN0M0	NEC	ESD, surgery	9 months alive
10	[36]	79	M	Esophagogastric junction	No symptoms	NA	NA	T1a	NEC, EC	ESD, surgery	4 years alive
11	[37]	63	M	37 cm	No symptoms	NA	NA	cT1aSM1	NEC, SCC, EC	ESD	15 months alive
12	[38]	55	M	Middle	NA	Type V1, type V2, type V3	NA	SM2	NEC, SCC	ESD, CTx	55 months alive
13	[39]	61	M	Middle	Epigastralgia provoked by swallowing	NA	There was thickening of the second layer, but the SM layer was not infiltrated, and it was judged to be a lesion in the mucosa	SM1	NEC	ESD, CTx, surgery	Lymph node metastasis 14 months later; lung metastases 17 months later; died 25 months later
14	[40]	70	M	Lower/33 cm	Discomfort when swallowing, weight loss	Type 3, type 4IB	The lesion was depicted as a hypoechoic area in layer 2; the third layer was preserved and the depth of the lesion was considered to be intramucosal	pT1b (SM: 200 μm)	NEC, SCC	ESD, CTx	Paracardial lymph node swelling 5 months later; died 22 months later
15	[41]	63	M	33 cm	A loss of appetite	NA	A 7 mm hypoechoic nodule on the mucosal layer with slight invasion to the submucosal layer	T1bN0M0	NEC	EMR	18 months alive

M: Male; F: Female; NA: Not available; GERD: Gastro-esophageal reflux disease; NBI: Narrow band imaging; EUS: Endoscopic ultrasound; SM: Submucosa; T: Tumor; N: Node; M: Metastasis; NEC: Neuroendocrine carcinoma; SCC: Squamous cell carcinoma; HGIN: High-grade intraepithelial neoplasia; EC: Esophageal carcinoma; ESD: Endoscopic submucosal dissection; CTx: Chemotherapy; RTx: Radiotherapy; EMR: Endoscopic mucosal resection.