Histiocytic lymphoma of the stomach (a case report).
While carcinoma of the stomach is a fairly common entity, lymphomas of the stomach are quite rare. We recently had, under our care, a case of gastric lymphoma. The rarity of its occurrence has prompted us to publish this case report.
A.B., a 65 year old male was admitted to the K.E.M. Hospital, on 17-3-1982 with the complaints of epigastric pain and discomfort after food, accompanied by weight loss of two months' duration. There was no history of haematemesis or melaena.
On examination he had a vague, ill-defined, mobile lump, about 10 cm x 15 cm in the epigastrium. The rest of the abdominal and rectal examination revealed no abnormality. The left supraclavicular lymph node was not palpable.
A barium study (done elsewhere) showed a large growth in the antral region of the stomach. Other investigations like urine, stools, haemogram, blood urea, blood sugar and serum electrolytes were within normal limits. A plain X-ray of the chest and ECG tracings were also normal. The clinical impression was carcinoma of the antrum of the stomach. A exploration under general anaesthesia on 22-3-1982, the patient was found to have a large tumour mass filling up the distal half of the stomach. The proximal stomach was dilated. The mass, though mobile, was adherent to the transverse colon and involved the middle colic artery. A few lymph nodes were palpably enlarged along the greater and lesser curvatures of the stomach. There were no secondaries in the liver or pelvis. The spleen was not enlarged.
A routine radical partial gastrectomy along with a partial colectomy (transverse colon) was carried out, followed by gastrojejunostomy and colocolostomy.
The excised specimen [Fig. 1] consisted of the stomach, transverse colon and the mesocolon along with the omentum. The stomach showed an ulcer, 9 cm x 9 cm in size, with everted indurated edges; the ulcer floor was whitish and contained 'necrotic material; the mucosal folds of the proximal stomach were hypertrophic.
Histological section [Fig. 2] from the ulcerated growth showed an irregular tumour mass, composed of sheets of tumour cells infiltrating all the coats of the stomach. The tumour cells were round to polygonal with large vesicular hyperchromatic nuclei with mitotic activity. There was cellular pleomorphism. The omentum showed tumour deposit. Transverse colon and mesocolon were free of tumour cells. The lymph nods showed sinus histiocytosis. The histological diagnosis, was stage II histiocytic lymphoma of the stomach.
The post-operative period was uneventful. Oral feeding was commenced on the 4th day and gradually built up. The sutures were removed on the 12th day and the patient was discharged on the 18th day. When last seen he was fit and had put on 3.5 kg in weight.
Primary malignant lymphomas of the gastro-intestinal tract comprise about l-4% of all malignant neoplasms of the gastro-intestinal tract. They most often affect the stomach and ileum and less often the colon and rectum. Involvement of the gut may appear as a part of dissemination of systemic lymphomatosis. In such instances, the lesions are typically multifocal whereas primary lymphomas are usually solitary masses in a particular segment of the gut.
The incidence of G.I. lymphomas varies from 25 to. 48%, our hospital incidence being 25% during the last 31/2 years (one out of four cases). Malignant lymphoma of the stomach has a slight preponderance in the males in the ratio of 1.5:1 and the average age of its occurrence is about 55-60 years.
In infants and children, the gastric mucosa has no lymphoid tissue; but in adults, aggregates of lymphocytes appear in the lamina propria. It is suggested that the usual precursor of extra-nodal lymphoma is a specific pathologic proliferative response of lymphoid tissue at the site. In many of these proliferations there are strong auto-immune aspects. Conditions like mal-absorption syndrome and the lymphoproliferative type of chronic gastritis provide a seed bed for a substantial fraction of lymphomas.
The classification of the lymphomas on gross are polypoidal, ulcerative and diffuse,,  in their incidence of occurrence. For histological classification there are a number of them; but, the one commonly followed is the modified Rappaport's classification.
Usually, a definite diagnosis of lymphoma cannot be made clinically, excepting occasionally, if a large mass with a large ulcerative growth and multiple polypoidal lesions seen on X-ray are present.
The commonest mode of presentation is with abdominal pain followed by cachexic symptoms, hematemesis and rarely perforation.
The best form of treatment is a curative resection followed by 3000-4000 rads of deep X-ray therapy. The 5-year survival rate following this therapy is about 20-30,% and 10-year survival rate is 15-30%. If surgical resection is not possible, only deep X-ray therapy may be given; but, the 5-year survival rate drops to 1.5%. The overall 5-year survival rate for lymphomas of the stomach, tonsils, and particularly lungs are better than carcinoma of the same organs; whereas, lymphomas of testis and breast are more lethal.
By and large, the extra nodal lymphomas have a better prognosis than. the nodal lymphomas. According to Freeman et al and Rudders et al, the survival rate is higher in the follicular variety than in the diffuse variety. Lymphocytic group has an overall better prognosis than the histiocytic group followed by the undifferentiated variety. The diffuse histiocytic lymphoma has the worst prognosis.
According to Ann Arbour staging, stages I and II have an overall better prognosis than stages III and IV. Our case lies in stage II.
Thanks are due to Dr. C. K. Deshpande, Dean, Seth G.S. Medical College and K.E.M. Hospital, Bombay, for permitting us to publish this hospital data.