Gastrointestinal autonomic nerve tumours and their separation from other gastrointestinal stromal tumours: an ultrastructural and immunohistochemical study of seven cases

Abstract

Gastrointestinal stromal tumours (GIST) represent a heterogeneous group whose classification frequently requires ultrastructural and immunohistochemical studies. In a retrospective study of the ultrastructural findings of 24 gastrointestinal stromal tumours, whose light microscopic study has yielded ambiguous results and in which accurate diagnosis had required ultrastructural support, seven were found to have the characteristics of gastrointestinal autonomic nerve (GAN) tumours. In all of them the diagnosis was based on the presence of dendritic processes with dense neuroendocrine granules. Immunohistochemically, the seven tumours were negative for smooth-muscle markers. All stained positively for vimentin. NSE, chromogranin, and synaptophysin were positive in most of them, while S-100 protein was positive only in two cases. We present the ultrastructural and immunohistochemical features of seven GANT against the background of the GISTs of our series. We conclude that GAN tumours cannot be diagnosed by light microscopy alone but this tumour group displays characteristic electron microscopic and immunohistochemical features and appears to represent a distinct type of GIST.

Differential diagnosis of gastrointestinal stromal tumor and other spindle cell tumors in the gastrointestinal tract based on immunohistochemical analysis

“…Information on NSE reactivity in GISTs is limited [7]. We found that over 80% of GISTs were NSE positive and that approximately 30% of non-gastric tumors were S-100 positive, suggesting the possibility of neural differentiation.…”

“…We found that over 80% of GISTs were NSE positive and that approximately 30% of non-gastric tumors were S-100 positive, suggesting the possibility of neural differentiation. Gastrointestinal autonomic nerve tumors (GANTs) are described as distinctive entities that differ from other mesenchymal tumors of the gastrointestinal tract [2,57], and most have been reported as immunoreactive for vimentin, NSE, and occasionally S-100 [7]. However, recent studies have suggested that GANTs are not a separate entity because they share a molecular genetic identity with conventional spindle and epithelioid cell forms of GIST [28].…”

Novel type of interstitial cell (Cajal-like) in human fallopian tube

“…)differentiate into smooth muscle cells, when ckit signaling is blocked [98]. Moreover, their malignant counterparts in GIST occasionally express either smooth muscle [99] or neuroendocrine [100] markers.…”

Autonomic nerve tumour with skeinoid fibres: ultrastructure of skeinoid fibres examined by quick-freezing and deep-etching method

“…The common sites are stomach, small intestine and retroperitoneum [3,14,15,20], but a case of oesophageal GANT was recently reported [19]. The clinical symptoms vary, including an enlarging abdominal mass, abdominal pain and gastrointestinal bleeding [14,15,22].…”