A primary gastric Adenosquamous carcinoma: Case report

Abstract

Introduction

Adenosquamous carcinoma (ASC) is too rare accounting for <0.5 % of all gastric cancers and has a worse prognosis than adenocarcinoma.

Case presentation

We report a case of a man with digestive symptoms and epigastric discomfort came to a Gastrointestinal clinic. CT scan of the abdomen and pelvis showed a large mass localized in the gastric fundus and cardia. A PET-CT scan showed a localized lesion in the stomach. Gastroscopy revealed a mass in the gastric fundus. Biopsy from the gastric fundus reported a poorly-differentiated squamous cell carcinoma. A laparoscopic abdominal exploration found a mass and Infected Lymphatic Nodes on the abdomen wall. a second biopsy reported an Adenosquamous cell carcinoma grade II. The therapeutic was open surgery and then chemotherapy.

Clinical discussion

Adenosquamous carcinoma usually presents at an advanced stage with metastasis (Chen et al., 2015). In our case, the patient presented with a stage IV tumor; including two lymph nodes metastasis (pN1, N = 2/15) and abdominal wall involvement (pM1).

Conclusion

Clinicians should be aware of this potential site of adenosquamous carcinoma (ASC) because this carcinoma has a poor prognosis even if diagnosed at an early stage.

Highlights

• •Epidemiology: Adenosquamous carcinoma (ASC) is a rare cancer accounting for less than 0.5% of all gastric cancers.
• •Case report: We report a case of a man with digestive symptoms and epigastric discomfort to the hospital.
• •Diagnosis: A PET-CT scan showed a localized injury in the stomach.
• •Pathology: the histological changes were: adenosquamous cell carcinoma grade II (the glandular component represents 10% of the tumor in the fundus region - the squamous component represents 90% of the tumor).
• •the tumor extends into the cardia-fundus region and body, tumor stage: tumor invades the muscular layer, margins: free and regional lymph nodes: pN1(N=2/15).

1. Introduction

Gastric cancer is the fourth most common cancer globally, and it is mainly caused by a genetic mutation in the stomach cells, which are lined by simple columnar epithelium [6].

In all pathological types, adenocarcinoma (AC) is the most diagnosed in patients, whereas adenosquamous carcinoma (ASC) is very rare, accounting for <0.5 % of all gastric cancers [2].

ASC has acquired great importance due to the lack of clear understanding of its histological composition [1].

Many hypotheses have discussed the origin of squamous carcinoma cells, however, the most prominent one is that squamous carcinoma cells are derived from adenocarcinoma [1]. In order to diagnose an (ASC), squamous component should be >25 % of the tumor mass [6]. Unfortunately, the majority of patients have been diagnosed at an advanced tumor stage [1].

Although there is no standard treatment protocol for ASC, surgical treatment remains the best option, followed by a postoperative adjuvant therapy. Chemotherapy and radiotherapy increase survival rate, especially because radiotherapy is effective against SC [1]. However, (ASC) has a worse survival rate than typical (AC) [2], whereas clinical therapies are not well established yet [1].

In this paper, we report a rare case of an (ASC) with the diagnosis and treatment protocols [7].

2. Presentation of case

A 57-year-old man with burps and abdominal discomfort presented to a private clinic. His medical history included losing 12 kg over the past three months. He also had been suffering from dysphagia, recurrent abdominal pain and epigastric discomfort for two years. He has no pathological nor surgical history. However, he has been a smoker of a pack and half per day for 25 years, and he has allergic to penicillin. According to his family history, his sister had lymphoma, his uncle had gastric cancer, and two other uncles had laryngeal carcinoma and brain cancer, respectively.

The laboratory tests were normal, But the stool sample was positive for occult blood.

An abdominal and pelvic computed tomography (CT) scan showed a large mass localized in the gastric fundus and cardia, measuring 107 mm as its maximum diameter; the rest organs were normal without any radiological signs of metastases. The lymph nodes were as normal too. The chest X-ray was clear.

A PET-CT multi slice scan showed a localized mass in the stomach with no metabolic activity detected.

An upper GI endoscopy showed a large and isolated mass in the gastric fundus, which a biopsy was taken from it. Histological examination revealed poorly- differentiated squamous cell carcinoma.

The therapeutic options were either to start with three rounds of chemotherapy and then surgery, or start with surgery immediately followed by chemotherapy. It was decided to start with surgery because of the patient's well health and the fact that chemotherapy could make him weaker and less comfortable with the surgery.

A laparoscopic abdominal exploration showed 10 cm mass and a suspected node on the abdomen wall above the liver.

Therefore, it was transformed into open surgery, included a total gastrectomy and biopsy from abdominal wall were performed with safety margins of 2.5 diameters from the esophagus, and 15 regional lymph nodes were resected. Then an intestinal anastomosis to the esophagus was made with lymph nodes adjacent to the gastric wall and nodes around the celiac curettage.

The second pathological report revealed that the histological changes were: adenosquamous cell carcinoma grade II (the glandular component represents 10 % of the tumor in the fundus region - the squamous component represents 90 % of the tumor), tumor size: 10 × 9 cm, the tumor extends into the cardia-fundus region and body, tumor stage: tumor invades the muscular layer, margins: free and regional lymph nodes: pN1(N = 2/15). The abdominal wall specimen revealed small foci of tumor cells (SCC, pM1), so the patient is in stage4 (pT2, pN1, pM1).

After one month the patient started the first round of chemotherapy, which has to be 8 rounds, each round composed of 150 mg cisplatin once every three weeks and 98 capecitabine 500 mg pills spread over 14 days at an average of 7 pills per day. However, the patient had some side effects such as impaired appetite and nausea without vomiting. Therefore, the therapeutic protocol was modified to Oxaliplatin 200 mg instead of cisplatin and kept capecitabin as usual, however the patient lost >10 kg in addition to the side effects so he refused to complete the last two rounds.

After the chemotherapy ended in three-month time, the patient conducted a CT scan, which was completely clear.

The patient recovered, and now he has a very good health, living normal life.

3. Discussion

Adenosquamous carcinoma is a rare malignant cancer of the gastric tract. It comprises about <1 % of all gastric cancers. In order to diagnose this mixed tumor, both adenocarcinoma and squamous carcinoma should exist in the biopsy, and the squamous component should be >25 % of the tumor.

Moreover, adenocarcinomas usually constitute the major component of the tumor [1]^, [2]^, [3]. Surprisingly, in our case, the squamous component was the dominant one, representing 90 % of the whole tumor.

There are five recommended possibilities of tumor histogenesis: [1] squamous metaplasia of an adenocarcinoma [2]; cancerization of metaplastic non-neoplastic squamous cells [3]; cancerization of the ectopic squamous epithelium [4]; differentiation of multipotential undifferentiated cancer cells toward both squamous and glandular cells; and [5]collision of concurrent adenocarcinoma and squamous cell carcinoma [4]. However, according to Ge, Yugang, et al., the histogenesis of this tumor remains unclear [5]. Therefore, further studies are required to explain the presence of these two mixed components together.

The adenosquamous carcinoma usually presents at an advanced stage with metastasis [2]. In our case, the patient presented with a stage IV tumor; including two lymph nodes metastasis (pN1, N = 2/15) and abdominal wall involvement (pM1).

Y.-Y. Chen et al. revealed that the tumor tends to behave more aggressively when the adenocarcinoma component comprises the major histological component of the invaded lymph nodes [2]. In our case, the involved lymph nodes were composed mainly of the squamous component. Therefore, this may be a sign of slightly less aggressive behavior, leading to a better overall survival rate. Nevertheless, the real correlation between the histological component and the prognosis is still inconsistent [5].

Chen et al. addressed that the two most common metastasis sites associated with this tumor are the liver and peritoneal dissemination [1]. Our patient did not develop metastasis to the liver within two months after surgery.

Shirahige A et al. reported that this carcinoma has a poor prognosis even if diagnosed at an early stage [4]. Yet, we should take into consideration that the case in that report had primary adenocarcinoma, prior to the adenosquamous carcinoma development. On the contrary, Y. Kimura et al. reported that the prognosis might be good if discovered at an early stage [6]. We still cannot tell which hypothesis is more reliable, and more studies are needed to solve this controversy.

According to its rarity, there is still no standard treatment for adenosquamous carcinoma. However, radical gastrectomy seems to be the most curative therapy [1]. According to Y. Kimura et al., chemotherapy improves the survival rate; and if there was lymph node invasion, it should be applied even if the tumor does not invade the submucosal layer [6]. Hence, given that the tumor in our case invades only the mucosal layer, we think that applied adjuvant chemotherapy might provide a better prognosis.

Ge, Yugang, et al. reported that radiotherapy improves the prognosis [5]. Unfortunately, we were not capable of applying radiotherapy because of the wide dissemination of the abdominal wall metastasis. In conclusion, given that the current tumor comprised majorly of the squamous component, and it is known that the squamous carcinomas respond well to this therapy, we think that an even better prognosis could be achieved if radiotherapy was applicable (Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5, Fig. 6).

Fig. 1.

Macroscopic images taken by upper GI endoscopy.

Fig. 2.

Macroscopic images taken by upper GI endoscopy.

Fig. 3.

Macroscopic images taken by upper GI endoscopy.

Fig. 4.

Macroscopic images taken by upper GI endoscopy.

Fig. 5.

The surgical pathology report.

Fig. 6.

The surgical pathology report.

Ethical approval

Ethical approval was provided by the authors institution.

Funding

Not applicable.

CRediT authorship contribution statement

Christine Alsheikh: Writing the paper.

Waad Alissa: Data collection.

Abdullah Aladnan Aljammas: Data analysis.

Maan Nashar: Study design.

Ziad Aljarad: Study design and providing us with information.

Guarantor

Abdullah Aladnan Aljammas.

Maan Nashar.

Christine Alsheikh.

Waad Alissa.

Take full responsibility.

Declaration of patient consent

The authors declare that they have obtained the parents' consent.

Consent for publication

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Declaration of competing interest

Not applicable.

Data availability

All data are included in this published article and its supplementary information files.