appunti del dott. Claudio Italiano
cfr prima Linfoma intestinale
In this particular form of primary lymphoma there is widespread involvement of a large tract or of the entire small intestine. Widespread intestinal lymphoma has a relatively high incidence in native populations of Middle Eastern countries. Adolescents and young adults (aged 15 to 40) are affected most frequently. Although widespread intestinal lymphoma is also observed in the Western world, it is much less common and affects a more advanced age group than in the Middle East. Symptoms and signs of intestinal malabsorption represent a prominent character. The clinical picture may resemble celiac sprue. Weight loss, diarrhea, steatorrhea, malaise, and asthenia are common.
Edema is often present, often in connection with plasma protein loss in the intestine, and anemia. Indeed, most of the various signs and symptoms that characterize malabsorption due to widespread lesions of the intestinal mucosa have been observed, at one time or another, in patients with primary diffuse lymphoma of the small intestine. On the other hand, fever, significant and often severe abdominal pain, and anorexia are usually prominent aspects of widespread lymphoma, while they are not so common in other diseases of the mucosa of the small intestine, such as celiac sprue, which cause malabsorption.
The abdomen may be distended and painful, but a palpable abdominal mass, common
in the focal form of the disease, is less common in primary diffuse intestinal
lymphoma. Drumstick fingers have often been noted.
Ascites, although less frequent than edema, can be marked when present. Lymphadenopathy and
hepatosplenomegaly are not part of the primary diffuse intestinal lymphoma,
while lymphadenopathy and hepatosplenomegaly are often observed. Steatorrhea is
usually a character in evidence when the disease becomes clinically complete. An
excess of fat is evident with the Sudan staining of faeces and the
quantification of fat excretion in feces documents the presence of malabsorption.
As would be expected, serum carotene and cholesterol levels are often lowered
and prothrombin time can be prolonged.
Indeed, laboratory findings, such as
clinical symptoms, closely resemble those seen in other diseases of the small
intestine with widespread lesions of the mucosa. The presence of an abnormal
immunoglobulin has been well documented in some patients with widespread
intestinal lymphoma. The abnormal immunoglobulin is of the IgA type, it is free
of light chains and is characteristically composed of heavy chains of the
subclass α 1. When it is detectable with the electrophoresis of the serum (about
50 percent of the patients who have this abnormality) , a broad band is usually
observed in the region of a2 and β-globulins. Small amounts of abnormal protein
can usually be found in concentrated urine samples, while large amounts may be
present in samples of jejunal secretions. Radiological examination of the small
intestine after a meal of barium is useful for evaluating patients with
widespread primary lymphoma of the small intestine. In some patients,
obliteration of mucosal folds, lumen dilatation and flocculation and barium
segmentation may closely resemble the radiological picture of celiac sprue. In
others, extremely coarse mucous folds are observed and the intestinal wall can
be extraordinarily thickened. The latter picture may resemble that of Whipple's
disease or amyloidosis. In Whipple's disease, however, the lesion is usually
more severe in the proximal tenuous, whereas in the lymphoma the distal gut may
be the severest portion. Peroral biopsy of the small intestine can provide a
definitive diagnosis if the biopsy intestinal segment is affected by the
neoplasm.
Tumor invasion of the small intestine in patients with disseminated lymphoma
may cause intestinal obstruction, fistulization, perforation and / or bleeding.
For the truth, the clinician is not usually aware of intestinal involvement
until the patient has the signs and symptoms of these complications. It should
be noted that bowel symptoms in patients with generalized lymphoma do not always
reflect intestinal lymphoma involvement. Usually, when the secondary involvement
in patients with a disseminated lymphomatous process becomes clinically manifest,
the nature of the underlying disease has already been established due to the
presence of extraintestinal manifestations.
Primary intestinal lymphomas must be distinguished from other neoplasms, benign or malignant, which give rise to the formation of lesions with mass characters in a segment of the small intestine. Carcinoma, sarcoma, fibroma, primary intestinal leiomyoma and carcinoid tumors can infiltrate the intestinal wall and, like lymphoma, can ulcerate and bleed. These same neoplasms may also present as intraluminal tumors, as do lipomas and adenomas, and all can intussuscepire and cause symptoms of intestinal obstruction.
Although the appearance of a mass-type lesion in radiological examinations with barium contrast may suggest a specific type of intestinal neoplasia, the definitive diagnosis requires laparotomy and histological examination of the tumor. In many cases, it is not difficult to distinguish between lymphoma and non-neoplastic infiltrative lesions of the small intestine such as Crohn's disease and tuberculosis or fungal enteritis. The extraintestinal manifestations of non-neoplastic diseases can help to differentiate them from lymphoma. In general, both small and large intestine involvement is more common and the total length of the affected intestine is usually greater in Crohn's disease than in lymphoma. In Crohn's disease, the stenotic lesions of the intestine are very frequent, while the stenosis is less common and usually associated with a more irregular aspect of the intestinal wall in the lymphoma. Often the intestinal lumen is of normal caliber or even dilated. However, sometimes the radiological appearance of non-neoplastic infiltrative lesions may resemble lymphoma so closely that surgical exploration is required to resolve the diagnostic dilemma. The clinical and radiological picture of patients with malabsorption caused by the influx of a long segment of the intestine by the lymphoma can closely reproduce the picture of other diseases of the intestinal mucosa with malabsorption such as celiac sprue, Whipple disease and amyloidosis . In fact, some patients with well-documented celiac sprue experience widespread intestinal lymphoma years after the onset of celiac disease. However, the frequency of this relationship is not well defined, because the widespread intestinal lymphoma in its early stages may resemble celiac sprue so closely that it is not always possible to determine whether a particular patient has had lymphoma from the beginning or if he he had celiac sprue at first and lymphoma developed later. In patients with diffuse intestinal lymphoma with malabsorption, fever is frequent and treatment with a gluten-free diet does not lead to significant improvement. Lymphoma can be distinguished from Whipple's disease by peroral biopsy; PAS-positive macrophages are not found in lymphoma and are always present in Whipple's disease. Biopsy can also be useful for discriminating intestinal amyloidosis from lymphoma. The appearance of intestinal symptoms in patients with previously diagnosed disseminated lymphoma deserves a thorough diagnostic evaluation, with appropriate radiological examinations, so as to be able to precisely define the nature of the lesion. Although secondary intestinal involvement is frequent in patients with disseminated lymphoma, the incidence of neoplastic lesions of this type that give rise to intestinal symptoms is not high.