Primary Lymphoma of Gastrointestinal Tract: A Rare Entity

Introduction

The function of the circulatory system is to transport various substances in the body. The lymphatic system is a part of the circulatory system. Small tube-like vessels carry lymph throughout the body and in between blood vessels. The function of the lymphatic system is to maintain the fluid level in the body and maintain immunity.

What Is Lymphoma?

The cancer of the lymphatic system is known as lymphoma. Around 5 percent of all malignant conditions are lymphomas. This is caused by the proliferation of T-lymphocytes, B-lymphocytes, and natural killer cells. The causative factors for lymphomas are:

1. Infectious Organisms: Infectious conditions like Borrelia burgdorferi, Chlamydia psittaci, and Campylobacter jejuni are associated with T-lymphocytic lymphoma. Mucosa-associated lymphoid tissue (MALT) lymphoma is a B-lymphocytic lymphoma caused by Helicobacter pylori. Other than this, viruses like the human T- cell lymphotropic virus, hepatitis C virus, and human herpesvirus 8 are associated with lymphoma.

2. Immunodeficiency: Immune-deficient conditions are associated with lymphoma. Organ transplants, HIV infections, and conditions like DiGeorge syndrome ( caused by the missing part of chromosome 22), agammaglobulinemia (an inherited disorder caused by the absence of B-lymphocytes), and Wiskott-Aldrich syndrome (rare immunodeficiency disorder) caused by immunodeficiency disorders are responsible for lymphomas.

3. Drugs and Chemical Substances: Chemical substances like alcohol, marijuana, LSD, and cocaine are associated with this type of carcinoma. Drugs like nonsteroidal anti-inflammatory drugs (NSAIDs), histamine2-receptor antagonists, psychotropic agents, and immunosuppressants are responsible for the increased risk of lymphoma.

4. Autoimmune Diseases: Autoimmune disorders are considered potential risk factors for lymphomas. Autoimmune conditions that are associated with an increased risk of lymphomas are Sjögren syndrome (a systemic condition associated with dryness of the eye and mouth), systemic lupus erythematosus (an autoimmune disorder of soft tissues), rheumatoid arthritis (an autoimmune inflammatory disorder), and Crohn disease (an autoimmune inflammatory disorder of the gastrointestinal tract).

Histologically lymphomas can be divided into two sub-types, these are:

1. Hodgkin Lymphoma: It is previously known as Hodgkin’s disorder. In this condition presence of distinct cells like Hodgkin Reed-Sternberg (HRS) cells can be found. These cells are B-lymphocytes in origin and appear as large bi-lobbed cells with two nuclei. The four sub-types of this type of lymphoma are; nodular sclerosis, lymphocyte-rich, mixed cellular type, and lymphocyte-depleted type.

2. Non-Hodgkin Lymphoma (NHL): This type of lymphoma arises either from T-lymphocytes or B-lymphocytes. The subtypes are follicular lymphoma, mantle cell lymphoma, Burkitt lymphoma, peripheral T-cell lymphomas, and diffuse large B Cell lymphoma. Diffuse large B-cell lymphoma (DLBCL) is the commonest and most aggressive type of lymphoma. In the gastrointestinal tract, this is the commonest type of lymphoma. Other than this, such types of lymphomas can be seen in the central nervous system, the eyes, and the testes.

What Are the Different Primary Gastrointestinal Lymphomas?

The gastrointestinal tract is one of the commonest sites for extra-nodal lymphomas. Around 40 percent of extra-nodal lymphomas are gastrointestinal in nature. According to WHO (World Health Organization), 4 percent of malignant gastrointestinal conditions belong to lymphomas. Most of the lymphoma of the gastrointestinal tract are non-Hodgkins in nature. But, such types of malignant conditions are rare and affect only 1505 people in 100,000 people. The common types of gastrointestinal carcinomas are:

1. Oropharyngeal Lymphoma: These types of lymphomas are the second most common types of extranodal lymphomas. Around 10 to 15 percent of malignant conditions in this region belong to lymphomas. The most common site for lymphoma in this region is Waldeyer’s ring, palatine tonsils, the base of the tongue, and oropharyngeal walls. Infection from the Epstein-Barr virus is considered a potential risk factor for this condition. The common symptoms of this condition are difficulty in swallowing, obstruction of the airway path, difficulty in hearing, and sensation of foreign body in the throat. This type of lymphoma is mainly diffuse B-cell type lymphoma. Histologically intermediate large cells can be found. Expression of B-cell antigens like CD19, CD20, and CD22 can also be noted. These lymphomas appear as lobular masses at the base of the tongue in radiological evaluations. Computed tomography imaging using molecular markers like 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) can be used for the actual detection of this type of condition.

2. Esophageal Lymphoma: Esophageal lymphoma is a rare entity. It is seen in less than one percent of cases. The main cause of this type of lymphoma is secondary to gastric lymphoma. Other than this, metastasis from cervical and mediastinal lymph nodes may also be responsible for such types of pathology. This is most commonly seen in immunocompromised patients and in HIV patients. Difficulty in swallowing, pain during swallowing, chest pain, and weight loss are the usual complication of such patients. In the endoscopy, the usual diagnostic features are ulcerated and nodular mass in the esophagus. Other than this presence of varicelloid patterns and tracheoesophageal fistula can also be seen.

3. Gastric Lymphoma: This is the commonest site for lymphoma in the gastrointestinal tract. 60 to 75 percent of cases of lymphoma of the gastrointestinal tract occur in this region only. Chronic inflammation and infection from Helicobacter pylori, Hepatitis B, and HTLV1 are the causative factors for this type of cancer. Most of the lymphoma in this region are either diffuse B-cell type lymphoma or mucosa-associated lymphoid tissue (MALT) lymphoma. In the endoscopic examination, polypeptides mass, ulceration, and diffuse infiltrations can be observed. In computed tomography (CT) imaging, swelling of the abdominal lymph nodes along with thickening of the gastric tissue folds can be seen. In magnetic resonance imaging, irregular thickening of the mucosal folds, submucosal infiltration, and exophytic tumor growth can be observed.

4. Small Intestine Lymphoma: The prevalence rate of lymphoma in the small intestine is only 2 percent. But 15-20 percent of carcinoma cases in the small intestine comprise lymphoma. The most common site for small intestine lymphoma is the ileum, followed by the jejunum and duodenum. Most of the lymphomas in the small intestine are mucosa-associated lymphoid tissue (MALT) in nature. Others belong to the category of either diffuse B-cell type lymphoma or mantle cell lymphoma. This type of lymphoma is mainly seen in patients aged over 50 years. Burkitt’s lymphoma is mainly seen in children or patients suffering from HIV. Hodgkin lymphoma of the small intestine is seen in extremely rare cases. Ultrasonography examination of the abdomen will reveal a hypoechoic mass with thickening of the wall of the small intestine. In the computed tomography examination, nodules and polypeptides can be observed.

5. Colorectal Lymphoma: Primary colorectal lymphoma is a rare entity, and in most cases, such lymphomas can be seen secondary to other diseases. This condition is mainly seen in old-aged male individuals. Most of the lymphomas of this region are B- cell in origin. Mantle cell lymphoma is the most common type of lymphoma in this region.

What Are the Treatment Options?

The main treatment option for lymphoma of the gastrointestinal tract is chemotherapy, followed by radiotherapy. Surgical resection can be done in cases like esophageal lymphoma and low-grade small intestinal lymphoma. Proton pump inhibitors, along with antibiotics, can be prescribed in patients with gastric lymphoma to prevent any kind of remission.

Conclusions

The carcinoma of the lymphatic system is known as lymphoma. Such types of carcinoma are mainly caused by infectious conditions and by immune-deficient conditions in the body. Gastric lymphoma is the commonest cancerous condition of the gastrointestinal tract. Other than this, conditions like esophageal lymphoma, lymphoma of the small intestine, and colorectal lymphoma can be seen. Such conditions can be treated by the application of chemotherapy or radiotherapy.