Page 1432 - Hematology_ Basic Principles and Practice ( PDFDrive )

1278 Part VII Hematologic Malignancies

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A B C

Fig. 79.1 NORMAL MARGINAL ZONE CELLS. (A) Marginal zone cells are seen most readily in sections
from the normal spleen. The splenic white pulp typically has three distinctive layers: the germinal center, the
mantle zone, and external to this, the marginal zone (see asterisk). (B) Marginal zone cells are not usually seen
in lymph nodes, but for some reason are sometimes present in mesenteric lymph nodes (see asterisk). They
have a similar appearance to those in the spleen. (C) In the gastrointestinal tract, the lymphoid tissue in Peyer’s
patches is believed to have a marginal zone equivalent (see asterisk). The cells are again external to the mantle
zone and are believed to traffic between the epithelium and the lymphoid follicle.

TABLE Staging Systems for Gastrointestinal Lymphomas the third to the ninth decades, and there is a slight female predomi-
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79.1 nance (55%). In contrast to most other indolent lymphomas,
ENMZL frequently presents at a localized stage (≈40% stage I and
Adapted Ann Lugano ≈30% stage II), and the risk for systemic dissemination is low (albeit
Arbor System 25 System 26 Paris System 27 Areas Involved a variable depending on primary location), which has important
IE1 I 1 T1 N0 M0 Mucosa to submucosa implications for the choice of therapy.
IE2 I 2 T2 N0 M0 To muscularis propria The most commonly affected primary site is the mucosa of the
or subserosa gastrointestinal tract, in particular the stomach (approximately 44%
T3 N0 M0 To serosa of all ENMZL cases) followed by the small intestine (≈7%). Ocular
IIE T4 N0 M0 To adjacent organs structures are also frequently involved (≈12%), namely, the orbit
(≈40% of all ocular adnexal ENMZL), the conjunctiva (35%–40%),
IIE1 II 1 T1–4 N1 M0 Regional lymph nodes b the lacrimal glands (10%–15%), and the eyelids (≈10%). Other
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IIE2 II 2 T1–4 N2 M0 Nonregional abdominal commonly affected sites include the bronchial mucosa (≈11% of all
lymph nodes ENMZL cases), the skin (≈9%), the salivary glands (≈6%), and the
IIIE IV T1–4 N3 M0 Extraabdominal lymph thyroid gland (≈6%). More rarely reported sites are Waldeyer pha-
nodes ryngeal lymphoid ring, breast, liver, pancreas, urogenital tract, and
central nervous system. 32–35 Findings at presentation depend on the
IV T1–4 N0–3 M1 Distant organs specific organ affected. Gastric ENMZL may lead to dyspepsia,
B1 Bone marrow epigastric pain, nausea, anorexia, and manifestations of gastro-
a In case of more than one visible lesion synchronously originating in the intestinal bleeding. Conjunctival ENMZL often forms a painless
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gastrointestinal tract, select the characteristics of the more advanced lesion. nodule or plaque that has a “salmon-pink patch” appearance and can
b Anatomic designation of lymph nodes as regional according to site: (a) 37
stomach: perigastric nodes and those located along the ramifications of the be associated with erythema, chemosis, and foreign-body sensation.
celiac artery (i.e., left gastric artery, common hepatic artery, splenic artery); (b) Primary cutaneous ENMZL frequently presents as multiple red to
duodenum: pancreaticoduodenal, pyloric, hepatic, and superior mesenteric violaceous papules, plaques, or nodules, most often on the trunk or
nodes; (c) jejunum/ileum: mesenteric nodes and, for the terminal ileum only, extremities, in particular the arms, which very uncommonly ulcer-
the ileocolic as well as the posterior cecal nodes; (d) colorectum: pericolic and 38
perirectal nodes and those located along the ileocolic, right, middle, and left ate. Salivary and lacrimal gland ENMZL are often preceded by sicca
colic, inferior mesenteric, superior rectal, and internal iliac arteries. syndrome, with xerostomia or xerophthalmia. B symptoms are
uncommon (≈15% of cases). 32
IPSID usually affects young adults, with no gender predominance,
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fungoides and Sézary syndrome, which may be used for the cutane- and is seen most commonly in the Middle East and Northern Africa,
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ous forms of ENMZL. usually in low socioeconomic status populations. The disease affects
the proximal small bowel diffusely and generally presents with a
EXTRANODAL MARGINAL ZONE LYMPHOMA malabsorption syndrome, with steatorrhea, hypocalcemia, weight
loss, abdominal pain, and fever. Cases involving the stomach, the
OF MALT TYPE colon, and very rarely, the respiratory tract have been described. 7
Epidemiology and Manifestations
Pathobiology and Differential Diagnosis
ENMZL is the most frequent of the MZL subtypes, accounting for
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approximately 8% of all NHL. A recent analysis of Surveillance, Etiology
Epidemiology, and End Results (SEER) data quotes a yearly incidence
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rate of 1.59 per 100,000 adults in the United States. The median ENMZL is strongly associated with chronic antigenic stimulation,
age of presentation is around 60, with a wide range spanning from including that deriving from chronic bacterial infections 15,17,40–59 or