“Crawling-type” adenocarcinoma of the stomach: a distinct entity preceding poorly differentiated adenocarcinoma

Abstract

Background Gastric ''crawling-type'' adenocarcinoma (CTAC) is a neoplasm histologically comprising irregularly fused glands with low-grade cellular atypia that tends to spread laterally in the mucosa. It is necessary to elucidate the clinicopathological characteristics of CTAC. Methods We evaluated 25 CTACs-16 intramucosal (M-) and 9 submucosal invasive (SM-) cancers-clinicopathologically and immunohistochemically. Results CTAC was most frequently located in the lesser curvature of the middle-third of the stomach. Macroscopically, 21 lesions were superficial-depressed and 4 were superficial-flat type. Histologically, all CTACs had cystic dilated glands and 16 lesions had focal signet-ring cells. All invasive areas of the SM-CTACs were occupied by poorly differentiated adenocarcinoma with an infiltrative growth pattern and abundant stroma. Fifteen CTACs were surrounded by mucosa with partial or no intestinal metaplasia. In the intramucosal area, 24 lesions were mixed phenotype with mucin and brush border immunoexpression. SM-CTAC was frequent in lesions with an intramucosal poorly differentiated component (PDC) greater than 10 mm in size (P = 0.041), and lymph node metastasis (LNM) was frequent in lesions with a PDC greater than 20 mm (P = 0.039). The frequency of an expanded pattern (Ki-67-positive cells occupying [ 50 % of the mucosa) was higher in SM-CTAC than in M-CTAC (P = 0.027). p53 overexpression was not detected in the intramucosal areas of any of the lesions. Conclusion CTAC is a distinct subgroup of gastric adenocarcinoma in the early phase. A larger PDC and a Ki-67 expanded pattern were predictive of submucosal invasion or LNM.

Very well-differentiated gastric carcinoma of intestinal type: analysis of diagnostic criteria

“…These previous studies reported some of the features that we assess here, including tortuous, branching, anastomosing, and distended glands, as well as the presence of discohesive cells. [1][2][3] A limited set of stromal features including desmoplasia and inflammation have also been noted previously. 3 The finding of 'spiky' glands, glandular outgrowth, and abortive glands as architectural features and the assessment of the remaining stromal features have not previously been described.…”

“…Very well-differentiated gastric adenocarcinoma of intestinal type is a distinct variant characterized by low-grade nuclear atypia and a morphology mimicking intestinal metaplasia. [1][2][3] The neoplastic glands show subtle architectural abnormalities such as branching and anastomosis, commonly reproducing the shapes of the letters W, H, Y, or X at low power. 4 Anecdotally, we have noted the challenge in diagnosing this variant of gastric adenocarcinoma, especially on biopsy specimens, which are often misinterpreted as reactive intestinal metaplasia.…”

“…5 Although it has been suggested that very well-differentiated gastric adenocarcinomas have low malignant potential with slow growth, some cases have been reported with transformation into diffuse-type morphology resulting in more aggressive behavior. [1][2][3]6 As a matter of fact, the spectrum of this variant of gastric adenocarcinoma, including its clinicopathological features and biological behavior, has not been well characterized because this entity is rare, noted to comprise only 1.9% of early gastric cancer, and it has been described in only a few small series. [1][2][3]5 Given the limited information available to date, we initiated this study to evaluate a series of very well-differentiated gastric adenocarcinomas of intestinal type in detail, with a notable focus on determining the key diagnostic features of this challenging lesion.…”

Clinicopathology of Early Gastric Carcinoma: An Update for Pathologists and Gastroenterologists

“…Nevertheless, intramucosal tubular adenocarcinoma has been confirmed to have a low risk of lymph node metastasis [14,18,19] and, therefore, can be safely removed endoscopically. In histopathology, most early tubular adenocarcinomas originate in the isthmus/neck of a gastric unit along the lesser curvature in the distal stomach [13,20]. A pathologic diagnosis of early tubular adenocarcinoma requires 2 essential histology features [20,21,22]: (1) nuclear dysplastic changes with hyperchromasia, nuclear enlargement in the size of 3-4 naïve small lymphocytes, high nuclear-to-cytoplasmic ratio, marked pleomorphism, increased mitotic figures with atypical forms, prominent nucleoli, and cellular immaturity; and (2) architectural abnormalities with a spectrum of growth patterns at low power view, such as anastomosing, fusing, branching, cribriforming, budding, back-to-back crowding, microcysts, disunion, spiky glands with sharp projections, single cell clusters, abortive glands, and necrotic debris in the gland lumens.…”

“…In histopathology, most early tubular adenocarcinomas originate in the isthmus/neck of a gastric unit along the lesser curvature in the distal stomach [13,20]. A pathologic diagnosis of early tubular adenocarcinoma requires 2 essential histology features [20,21,22]: (1) nuclear dysplastic changes with hyperchromasia, nuclear enlargement in the size of 3-4 naïve small lymphocytes, high nuclear-to-cytoplasmic ratio, marked pleomorphism, increased mitotic figures with atypical forms, prominent nucleoli, and cellular immaturity; and (2) architectural abnormalities with a spectrum of growth patterns at low power view, such as anastomosing, fusing, branching, cribriforming, budding, back-to-back crowding, microcysts, disunion, spiky glands with sharp projections, single cell clusters, abortive glands, and necrotic debris in the gland lumens. Recognition of the morphologic characteristics of early tubular adenocarcinoma is crucial in small biopsies to guide patient triage and management, as most patients with early tubular adenocarcinoma are treated by endoscopic, rather than surgical resection in East Asian countries.…”