A resected case of neuroendocrine carcinoma of the stomach with unusual lymph node metastasis

Abstract

Gastric endocrine cell carcinoma is a relatively rare tumor. We experienced a case of early gastric cancer in which an endocrine cell carcinoma was identified within a differentiated adenocarcinoma, and a component of this endocrine cell carcinoma had metastasized to lymph nodes of the stomach. In its 2010 revision regarding digestive system tumors, WHO classified cancer cells with characteristics of both glandular system cells and neuroendocrine cells as mixed adeno neuroendocrine carcinoma (MANEC) under the neuroendocrine carcinoma (NEC) category. In this case, we observed an endocrine cell carcinoma continuous with an intramucosal differentiated adenocarcinoma, and cancer cells with an irregular gland duct structure were observed in the proliferative portion of the submucosal tissue. In addition, there was a 35 mm size lymph node metastasis in the lesser curvature of the stomach consisting entirely of poorly differentiated cancer cells with polymorphic, highly atypical nuclei and scant cytoplasm. Immunohistological analysis showed that the endocrine carcinoma in the gastric mucosa was chromogranin A positive and the infiltrated area of the submucosal tissue was also chromogranin A positive. The lymph node metastasis was positive not only for chromogranin A, but also for Synaptophysin and CD56. Furthermore, the Ki67 labeling index was high at approximately 80 % for the gastric endocrine cell carcinoma and approximately 90 % for the lymph node metastases. Until now, there are no reports related to the patients with early gastric cancer accompanied with lymph node metastasis of MANEC. This case is very interested in considering the mechanism of lymph node metastasis of MANEC. The patient has shown no sign of recurrence for 1 year and 4 months after postoperative chemotherapy.

Mixed Neuroendocrine Non-Neuroendocrine Neoplasms: A Systematic Review of a Controversial and Underestimated Diagnosis

“…The quantitative composition of the primary tumour was described in 36 studies (n = 294) [12,15,17,19,21,[23][24][25]27,29,30,34,36,[39][40][41]45,46,[48][49][50][52][53][54]56,57,59,65,73,74,80,82,[84][85][86]92]; the two components were present in equal proportion in 27.9% (n = 82) of cases, whereas in the remaining 72.1% one of the two histologies was predominant; the neuroendocrine component in 42.2% (n = 124), the non-neuroendocrine component in 29.9% (n = 88).…”

“…Among 69 studies (n = 667) reporting the grade of differentiation of the neuroendocrine component [11][12][13][14][15][16][17][18][19][21][22][23][24][25][26][27][28][29][54][55][56][57][58][59][60][61][62]68,71,[73][74][75]79,80,82,[84][85][86][87]89,[91][92][93]96,97,100,101], a large proportion of MiNENs (92.5%; n = 617) had a grade 3 neuroendocrine component, whereas 4.3% (n = 29) and 3.1% (n = 21) had a grade 1 and a grade 2 neuroendocrine component, respectively. Among MiNENs with a grade 3 neuroendocrine component, the morphological subtype (large cell or small cell) was reported in 25 studies (n = 241) [11,…”

“…Interestingly, in 43 studies (n = 61) where more than one diagnostic sample was available [11,[13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28]30,[32][33][34][36][37][38][39][41][42][43][44][45][46][47]49,50,53,55,[59][60][61][62]64,65,96], the initial diagnosis from the first sample collected (either cytological or histological) was in keeping with MiNEN or suspicion of MiNEN in 36.1% (n = 22) of cases, adenocarcinoma in 36.1% (n = 22), poorly differentiated neuroendocrine carcinoma in 21.3% (n = 13), and well differentiated neuroendocrine tumour in 6.6% (n = 4).…”

Gastric Neuroendocrine Carcinoma with Rapid Progression

“…Mainly cases diagnosed as MANEC after ESD and additional surgery and those diagnosed as NEC from a metastatic lesion following ESD have been reported (12)(13)(14)(15)(16)(17). A search of PubMed for case reports (between 1998 and 2018) of gastric NEC diagnosed at early stages yielded only seven cases, including ours, in which the patient age, sex, site of occurrence, and depth of invasion could be assessed in detail (Table) (12)(13)(14)(15)(16)(17). Most cases had been diagnosed as having adenocarcinoma based on a biopsy obtained before the first treatment, and those diagnosed with NEC by a biopsy were extremely rare.…”