Sato Y, et al. J Gastric Cancer. 2018 Aug;18:e33. https://doi.org/10.5230/jgc.2018.18.e33

Neurofibromatosis type 1 (NF1) is an autosomally dominant inherited disorder characterized by multiple pigmented skin spots (café-au-lait spots) and neurofibroma. NF1 is associated with a wide variety of benign or malignant tumors. We report a NF1 patient who received surgical treatment for rectal carcinoma and multifocal small intestinal gastrointestinal stromal tumors (GISTs). A 70-year-old female patient with NF1 was referred to our hospital after a positive fecal occult blood test. Locally advanced rectal carcinoma was detected in the upper rectum using colonoscopy. A submucosal tumor 20 mm in diameter was detected in the duodenal bulb during the upper gastrointestinal endoscopy. The biopsy specimen from the duodenum was GIST with positive immunostaining of KIT and CD34 microscopically. Laparoscopic low anterior resection for rectal carcinoma and local excision of the duodenal GIST were performed successfully. During the operation, five white small nodules were found on the serosa of the jejunum. One nodule was excised for histological examination. The resected rectal tumor was a well-differentiated adenocarcinoma with multiple lymph nodes metastases according to the histology. The duodenal tumor was found to be low-risk GIST. Moreover, the nodule from the jejunum was very low risk GIST. An excised skin wart was neurofibroma according to the histology. GIST or carcinomas have been reported to occasionally occur in the digestive tract of the patients with NF1. We present a rare case of a NF1 patient with GISTs and colorectal carcinoma.

BackgroundPrimary gastric squamous cell carcinoma (SCC) is a very rare disease. The origin of this tumor remains unclear, although there are some hypotheses.Case summaryA 60-year-old man consulted a previous physician complaining of upper abdominal pain. Esophagogastroduodenoscopy revealed type 2 gastric cancer, and the patient was referred to our hospital. After close examination, the patient was diagnosed as cStage IIA gastric adenocarcinoma, and distal gastrectomy was performed. Histochemical studies showed typical findings of SCC, and the tumor was surrounded by intestinal metaplasia. Immunohistochemical examination was positive for cytokeratin (CK) 5/6 and caudal-type homeobox protein 2 (CDX2) and negative for p63/p40.ConclusionThe results of immunostaining for CK5/6 supported that this tumor was SCC, but the question why p63/p40 were negative and CDX2 was positive still remained. Concerning about the origin of p63/p40 and CDX2, it was suggested that the tumor cells were not derived from ectopic squamous epithelium but from intestinal metaplasia. And tumor cells looked like homogeneous and squamous metaplasia was not observed. These findings supported the idea that these tumor cells arose from stem cells in the intestinal metaplasia of the stomach.

Gastric cancer exhibits various degrees of fluorine F-18 fluorodeoxyglucose (18F-FDG) uptake on positron emission tomography/computed tomography (PET/CT). We evaluated the relationship between 18F-FDG uptake and the presence/absence of metastasis in individual lymph nodes (LN) on a one-to-one basis. We analyzed 21 patients with gastric cancer. We injected 18F-FDG intravenously in the morning, and gastrectomy with LN dissection was performed in the afternoon of the same day. Radiation doses were measured at each LN using a well-type counter, and we then compared 18F-FDG uptake, the shortest diameter, and pathological examination results for each LN. In our study, 906 LNs were analyzed, including 115 metastatic LNs. Metastatic LNs showed significantly higher 18F-FDG uptake (P < 0.0001), and were significantly enlarged (P < 0.0001). The receiver operating characteristics (ROC) curve had a larger area under the curve (0.71) for 18F-FDG uptake than for the shortest LN diameter (0.60). Considering histology, the ROC curve for intestinal type adenocarcinoma had a larger area under the curve than that for diffuse type (0.75 vs 0.61). F-FDG uptake is potentially a more useful variable than LN diameter for discriminating between LN with and without metastasis, especially in intestinal type gastric cancer cases.

Background: It is unknown whether transmediastinal esophagectomy (TME) is an acceptable surgical procedure for locally advanced esophageal squamous cell carcinoma (ESCC). Therefore, we investigated the feasibility of long-term survival after TME with neoadjuvant docetaxel, cisplatin, and 5-fluorouracil combination chemotherapy (DCF therapy). Methods: This retrospective, observational study included locally advanced resectable ESCC. All patients received two cycles of preoperative DCF therapy (60 mg/m² of docetaxel and cisplatin on day 1 and 700 mg/m²/day of 5-FU on days 1–5 in each cycle) followed by radical TME. The main outcomes were survival and the rate of adverse events of chemotherapy and surgery. Results: Sixteen patients were included in this study. All patients received two cycles of DCF therapy, followed by surgery. The median follow-up duration of the 16 patients was 35.4 months. The 2-year overall survival (OS) was 93.3% (95% confidence interval [CI], 61.3–99.0), and the 3-year OS was 78.8% (95% CI, 47.3–92.7). The 2-year and 3-year relapse-free survivals were both 73.3% (95% CI, 43.6–89.1). Leukopenia and neutropenia occurred in most patients; however, they were controllable. Fifteen patients completed TME, and one was converted to open transthoracic esophagectomy because of tracheal injury. Three-field dissection was performed for 12 of 16 patients (75%), and R0 resection was achieved in 15 of 16 patients (93.8%). Three cases of grade IIIb chylothorax were observed. There was no mortality in this study. Conclusion: Combined neoadjuvant DCF and TME for locally advanced ESCC was safe and less invasive than traditional therapies and had a satisfactory long-term prognosis.

Background: Gastrointestinal stromal tumors (GIST) arising from sites other than the gastrointestinal (GI) tract, termed extra-gastrointestinal stromal tumors (EGIST), are rare. Among EGIST, those with platelet-derived growth factor receptor alpha (PDGFRA) mutations are even rarer, with only a few cases reported. About 80% of GIST has KIT mutations, and 10% of GIST have PDGFRA mutations, which commonly affect the TK2 domain (exon 18). Among the exon 18 mutations, the D842V substitution is limited to gastric GIST. In EGIST, the degree of KIT and PDGFRA mutations varies on where the location of the tumor is, and it is suggested that omental EGIST is similar to gastric GIST. Adjuvant imatinib therapy is recommended for high-risk GIST; however, it is known that imatinib is less effective against GIST with a PDGFRA D842V mutation. Case presentation: A 75-year-old man was referred to our hospital with an extrinsic tumor of the lesser curvature of the gastric body. Intraoperative findings showed a tumor located outside of the lesser omentum with no connection between the tumor and the gastric wall. The tumor was subsequently resected. Pathological examination indicated a GIST arising in the lesser omentum measuring 70 mm in its longer dimension. Because the tumor had a PDGFRA mutation (D842V substitution), imatinib was suspected to lack efficacy to the tumor. Thus, although the tumor was considered clinically to have a high risk of recurrence, adjuvant imatinib therapy was not indicated. The patient has been free of recurrence for 29 months since the surgery. Conclusion: We described a case of EGIST with a PDGFRA mutation arising in the lesser omentum. And we reviewed 57 cases of omental EGIST and showed that the clinicopathological characteristics and mutation status in omental EGIST were very similar to gastric GIST. In particular, PDGFAR D842V mutation rate in omental EGIST seemed as high as that in gastric GIST. These results suggested that omental EGIST is strongly related to gastric GIST, so the behavior of omental EGIST might be akin to gastric GIST. However, further studies are required to determine the prognosis and the necessity of adjuvant therapy for EGIST with a PDGFRA mutation.