Case Report : A case of metastatic adenocarcinoma found during inguinal hernia repair

Tumors found during hernia repair are rare. They may be intrasaccular (most commonly), saccular or extrasaccular, and they are usually primary. In this case report we present a case of metastatic adenocarcinoma (confirmed by biopsy) found inside the inguinal hernia sac. Following further investigation, primary tumor of the ileum and ileocecal junction was found. An elderly male presented with a history of bilateral inguinal swelling for a year, that had been asymptomatic initially, but had increased in size and was painful following prolonged activity. During laparoscopic hernioplasty a right sided inguinal hernia with nodules on peritoneum and omentum were observed. After taking a biopsy, repair of the hernia was performed. Carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 levels were raised. A computed tomography (CT) scan of the abdomen and chest showed a mass involving the distal ileum and the ileocecal junction, with lymphadenopathy, peritoneal carcinomatosis, as well as hepatic and lung metastasis. Surgery was not possible in this patient. A possible relation of an inguinal hernia with an ileal neoplasm was found in this patient. An irreducible swelling not causing any problems can be suspicious, which should be properly investigated to get to an early diagnosis.


Competing interests:
The author(s) declared that no grants were involved in supporting this work.

Introduction
Inguinal hernia sac tumors are a rare occurrence, with one study reporting only 0.07% of repairs being positive for metastatic tumors 1 .Traditionally, hernia sac tumors are classified as intrasaccular, saccular and extrasaccular, based on the anatomical relationship of the tumor to the hernia sac 2,3 .Intrasaccular tumors are one the most frequent type.They generally consist of primary tumors of organs lying within the hernia sac, such as cancers of colon, bladder, and metastatic neoplasms involving the omentum.
Tumors that extend into the hernia sac by way of peritoneal involvement are classified as saccular and include, among others, primary mesothelioma and peritoneal metastasis from the intra-abdominal organs.When the tumor is within the hernia defect but lies outside the hernia sac, it is classified as extrasaccular.Examples include metastatic involvement of inguinal lymph nodes [2][3][4] .In this case report we present a case of metastatic growth that was found inside the inguinal hernial sac, later confirmed by histopathology to be metastatic adenocarcinoma.Post-operative workup revealed the primary tumor to be an adenocarcinoma involving the distal ileum as well as the ileocecal junction.

Case presentation
A 57-year-old man, with no known comorbid, from Karachi, Pakistan, was admitted to the Civil Hospital, Karchi, Pakistan, in November 2017, with a history of bilateral inguinal swelling that had begun a year prior to presentation, that had been small and inconsequential initially, but had recently grown larger and would become painful during prolonged standing and walking.In last three weeks prior to admittance, the swelling would not reduce with lying down.On physical examination, he was found to have a bilateral, incomplete, non-reducible inguinal hernia.His baseline laboratory investigations were all within normal limits, and chest radiograph was unremarkable.The patient underwent a cardiac review and was declared fit for general anesthesia.He was scheduled for laparoscopic hernioplasty.Intra operative findings revealed white nodules on parietal peritoneum and the omentum, while only the right-sided inguinal hernia was observed.A biopsy was taken, and mesh repair was done on the right side.Histopathology of the biopsy showed metastatic adenocarcinoma.The patient was evaluated for an intra-abdominal neoplasm.Carcinoembryonic antigen (CEA) levels and carbohydrate/cancer antigen (CA 19-9) levels were sent and patient scheduled for an ultrasound scan (US) of the abdomen and pelvis, esophagogastroduodenoscopy (OGD), colonoscopy and computed tomography (CT) scan of the chest, abdomen and pelvis with contrast enhancement.The patient's CEA levels were 14.04 ng/ml (normal level <3.5 ng/ml) and CA 19-9 levels were 125.2 U/ml (normal level <27 U/ml).The only findings of the abdominal and pelvic ultrasound were hypo-echoic lesions in the liver.OGD showed antral gastritis and biopsies were taken which showed no evidence of malignancy.
Colonoscopy showed rounded well-demarcated lesions measuring 1.5 cm seen in the cecum, multiple biopsies were taken.However, biopsy showed no evidence of malignancy.Computed tomography (CT) of abdomen and chest showed a mass involving the distal ileum and the ileocecal junction, with lymphadenopathy, peritoneal carcinomatosis, as well as hepatic and lung metastasis (Figure 1).The patient was considered inoperable and hence, no surgery was considered.The patient left against medical advice and no follow up was obtained.

Discussion
Malignant tumors presenting within inguinal hernias are a rare occurrence.Literature reveals less than 0.4 % of the excised hernia tissue shows microscopic evidence of neoplasia 5 .Among these the most common primary tumor associated with hernia sac metastasis is carcinoma of the colon 2,5 .This case was unique as in our patient the neoplasm involved the small bowel (distal ileum) as well as the ileocecal junction.To our knowledge, there is no literature available which mentions a case of metastatic ileal/ileocecal junction neoplasm presenting as an inguinal hernia.
In most cases of colon cancer presenting as an inguinal hernia one possible explanation for the occurrence of an inguinal hernia could be the increased intra-abdominal pressure, perhaps secondary to the intra-abdominal neoplasm, occurring especially in the elderly 2,6 .For instance, obstructive colon cancer, massive tumors or tumors associated with ascites can lead to increased intra-abdominal pressures and result in an inguinal hernia.However, in our patient, there were no additional symptoms, indicating that other factors were involved.
Here we turn to the history the patient gave us on presentation.A patient's presenting complainant is an important factor and can raise suspicion of an underlying malignancy 3 .It has been suggested that a long-standing hernia, becoming acutely incarcerated has a greater chance of containing a tumor.Some authors have even gone so far as to say that any non-reducible mass in the inguinal canal, lacking an impulse, should raise concern for malignancy 3 .Furthermore, constitutional symptoms can also suggest the possibility of an underlying malignancy.In many such cases, abdominal pain was the most frequent symptom present pre-operatively 3 .Of note in our patient is the history of acute incarceration, as the patient said that up till recently the swelling would reduce on lying down.Since the peritoneum is a common site of intra-abdominal metastasis, a hernia repair gives a good opportunity for the surgeon to perform a peritoneal biopsy, thereby providing an earlier diagnosis.Furthermore, due to reports of occult malignancies from histopathological examination of hernia sac, several authors have recommended routine microscopic examination of the hernia sac 2,7 .However, other authors have reported histopathological examination in only selected cases 2 .Several authors also suggest a routine fiberoptic sigmoidoscopy in patients presenting with a hernia, because of the coexistence of an inguinal hernia and colonic cancer 2,8 .

Conclusion
In conclusion, our study showed that an inguinal hernia and ileum/ileocecal junction neoplasm can coexist together, especially in the elderly.In addition, we also reported that an irreducible hernia can raise suspicion of metastasis and, the patient can be asymptomatic at the time of presentation.Despite the rare co-existence of hernia and malignancy, we still recommend routine microscopic histopathological examination in all suspicious cases, as this can lead to an earlier diagnosis, and if the patient is asymptomatic this can be the only means to determine an occult malignancy.

Consent
Written informed consent for publication of their clinical details and clinical images was obtained from the patient.
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