Less than 5% of gastrointestinal cancers are small intestine cancers, making them an uncommon type of cancer.  Black people have a greater prevalence rate than white people, with an estimated yearly incidence of 0.3 to 2.0 cases per 100,000 people. This incidence has been rising recently [1, 2].  The prevalence rises after age 40, with the most common diagnosis occurring in those between the ages of 55 and 64.  The United States currently has a 65.5% 5-year survival rate; the length of survival is significantly influenced by the stage of cancer upon diagnosis [3]. There are four major histological kinds of small intestinal cancer: sarcoma (10–15%), carcinoid tumor (35–42%), lymphoma (15–20%), and adenocarcinoma (30–40%) [4]. The duodenum is where adenocarcinoma of the small intestine (ASI) most frequently occurs (57%), followed by the jejunum (29%), and the ileum (10%) [5]. A diagnosis of ASI is typically delayed by 6 to 10 months because to the nonspecific abdominal discomfort that manifests clinically as abdominal pain, nausea, vomiting, gastrointestinal bleeding, and intestinal blockage [6]. Since ASI is a rare cancer, no effective screening techniques have been developed, and little is known about the prognosis, treatment options, and clinical features of ASI patients, particularly Asian individuals.

Here, we report on a 55-year-old man with a complaint of swelling over the medial aspect of right thigh. He was diagnosed until he had an incomplete small Intestine obstruction. Patient was managed conservatively with chemotherapy. The patient was given Oxaliplatin 180mg and Capecitabine 500mg for 14 days in 21 cycles. The patient was also referred for radiotherapy. The patient was doing well as of his last follow-up.

A 55-year-old male patient presented to us with a complaint of swelling over the medial aspect of right thigh. The patient also had an associated complaint of pain over the swelling. On elaborating origin, duration and progression, the patient noticed the swelling two weeks ago and was of the same size. It was initially painless but later developed pain.

Physical Examination Findings

On examination, the swelling was 10×6cm in size. The swelling was firm to hard in consistency, tender and fixed to underlying muscles. All other physical examination findings were unremarkable. The patient did not have any complaints of loss of function in the right lower limb, fever, weight loss, fatigue and anorexia. MRI of the right thigh was performed. It demonstrated two fairly large, well-defined abnormal signal intensity lesions in intramuscular and intermuscular regions with spindle shape with the craniocaudally and peripheral thick enhancing wall. The lesions were hyperintense on T2 and hypointense on T1 with central non enhancing necrosis. The lesions were seen in medial compartment of upper half of right thigh. The lesions were located along the neurovascular bundle. The larger lesion measured approximately 8.8(cc)×3.5(w)×2.2(AP) cm. No perilesional edema was seen. On the basis of MRI findings, a provisional diagnosis of nerve sheath tumor was made. The decision for undertaking an excisional biopsy was made. Excision biopsy was done under spinal anaesthesia and the postoperative period was uneventful. The patient was discharged following the biopsy and was asked to come for follow-up when he received his biopsy results.

Follow-up Study

The patient came after two weeks. The biopsy of the tumor revealed that it was composed of nests, cords and focally gland-forming tumor with large pleomorphic tumor cells and frequent mitosis. Many of the cells show intracytoplasmic mucin. Extensive area of necrosis was also seen. Also on the same follow up visit, the patient also had a complaint of a swelling in left supraclavicular region since 5 days. On examination, swelling was 5×3cm in left supraclavicular region. The overlying skin was normal with no abnormal pulsations. Mild tenderness was present. Transillumination test and slip sign were negative.

On the basis of history and physical examination a provisional diagnosis of lymphadenopathy was made. For further investigating the etiology, USG of the local part was done and it revealed multiple enlarged lymph nodes in the left supraclavicular region over the left side of the neck with surrounding fat stranding. Few of the lymph nodes appeared necrotic. Further FNAC of the enlarged lymph node was conducted. The smear prepared from the aspirate contained cells. It showed malignant epithelial cells in discohesive clusters as well as singly. The cells showed nuclear pleomorphism and high N:C, coarse chromatin, irregular nuclei, prominent nucleoli and scanty cytoplasm. Bizarre cells were also seen. The results of the FNAC pointed towards a metastatic epithelial malignancy, possibly an adenocarcinoma.

To locate the primary tumor, a colonoscopy was performed, which revealed normal mucosa and vascularity in the entire colon and upto 5 cm of terminal ileum, Figure 1.

Figure 1: Microscopic images of the tumour from the pathologic specimen

Full body CT scan was done to locate the primary. CT revealed eccentric enhancing wall thickness in proximal ileal loop in mid abdomen in supra umbilical region representing a neoplastic etiology.

Metastatic lesions were also seen in the eighth segment of right lobe of liver, bilateral adrenal glands, left perinephric space and abdominal wall on both sides. Also, ill-defined lytic lesions were visualized in right paravertebral region extending from L3 to L5 level. Multiple para-aortic, aortocaval, retrocaval, mesenteric, bilateral iliac and and right inguinal nodes were enlarged representing nodal spread.

Final Diagnosis

Metastatic Adenocarcinoma of Small Intestine was to be done. Diagnosis was made on the basis of CT results, supported by the results of FNAC of supraclavicular lymph node and biopsy of the tumor on the thigh.

Post-Operative Course

Patient was managed conservatively with chemotherapy. The patient was given Oxaliplatin 180mg and Capecitabine 500mg for 14 days in 21 cycles. The patient was also referred for radiotherapy.

Although the small intestine makes up 90% of the absorptive mucosal surface area and 75% of the digestive tract's length, small intestine tumors are less common than other gastrointestinal cancers.  The higher IgA levels and the smaller intestine faster transit than the large colon are two potential causes.  The low prevalence of tumors is also attributed to the small intestine's sensitivity to stress and the presence of fewer germs [7].  Small intestine cancer is typically seen in older persons [3], but in this instance, it was discovered in a young guy who was 55 years old.  Until he developed a partial small intestinal blockage with lymph node metastases, the lump was invisible. Several swollen lymph nodes in the left supraclavicular region over the left side of the neck with surrounding fat stranding were found in this study, which was comparable to others where the diagnosis of ASI was primarily made at advanced stages.  There weren't many lymph nodes that looked necrotic.  The swollen lymph node underwent further FNAC [8].

To find the primary, a full body CT scan was performed.  A malignant etiology was indicated by the CT scan of the mid-abdominal region's proximal ileal loop, which showed eccentric increasing wall thickness.  The total accuracy rate of CT scans for diagnosing ASI is 47%.  Although CT scans are capable of identifying lesions, they are unable to provide accurate information about the intestinal mucosa and may overlook small or flat lesions.  To distinguish between benign and malignant small intestine tumors, the PET/CT technology is utilized [9].

The preferred treatment for localized ASI is still surgical excision with clear margins and regional lymph node resection; in fact, because of the high risk of blockage or severe hemorrhage, these procedures are sometimes necessary even in cases of metastatic ASI [10].  There is currently no established chemotherapeutic treatment for ASI.  Palliative chemotherapy's role in advanced ASI has been the subject of numerous investigations.

CONCLUSIONS

We report a rare case of adenocarcinoma of the small intestine (ASI) in a 55-year-old male. Diagnosis of ASI remains a challenge. A physician’s suspicion and awareness is crucial in patients with swelling over the medial aspect of right thigh.

The patient was given Oxaliplatin 180mg and Capecitabine 500mg for 14 days in 21 cycles. The patient was also referred for radiotherapy. The patient was doing well as of his last follow-up. Because the incidence of ASI is very low, there is a need for further studies to evaluate the possible application of newer investigative agents and strategies to obtain a better outcome within the framework of international collaborations.

Funding: No funding sources

Conflict of interest: None declared

Ethical approval: The study was approved by the Institutional Ethics Committee

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that her name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed.

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