14
Alimentary Tract (Esophagus, Stomach, Small Intestine, colon, Rectum, Anus, Biliary Tract)
Fig. 14.26 Mycobacteria. (A) Scattered histiocytes are present, some with linear striations in their cytoplasm (Papanicolaou stain x HP). (B) Acid-fast bacilli
(AFB) stain of histiocytes (AFB x HP).
Fig. 14.27 Benign lymphoid hyperplasia. This manifests as numerous
dyshesive lymphocytes. Most are small and mature appearing. A fewer larger
transformed lymphocytes with prominent nucleoli are present. Near the
center of the field is a tingible body macrophage. The polymorphism is a clue
to the benign nature of this process (Papanicolaou x HP).
Malignant Lymphoma
Relative to other portions of the alimentary tract, malignant
lymphomas occur commonly in the small bowel vis-à-vis other
malignancies. However, the majority occur distal to the duode-
num, and thus they are sampled rather infrequently in endo-
scopic biopsies and brushings. In a large review by Domizio and
associates, the single most common and prominent feature at
presentation was abdominal pain, often related to intestinal per-
foration with peritonitis.165 Other presenting features included
weight loss, obstruction, diarrhea, and an abdominal mass.
One-third of the neoplasms were T cell in type, which is rare in
the remainder of the GI tract. Grossly, the T-cell neoplasms typi-
cally presented as an ulcer, stricture, or plaque in the jejunum.
The B-cell neoplasms tended to be larger and to occur as annular
or exophytic masses in the ileum. A much greater proportion of
the T-cell tumors were histologically high grade and most often
were of the pleomorphic medium and large-cell size variants.165
Overall, the cytologic appearance of duodenal lymphomas
in brushings should closely resemble those obtained from the
stomach. Streaks of rather large, noncohesive, and monomorphic
cells with high N/C ratios need to be distinguished from reac-
tive inflammatory elements. The atypical appearance of the
cells, their overall uniformity, and a predominance of large
cells are crucial in this distinction. Nuclear membranes are dis-
tinct and often have irregularities in the form of indentations,
cleaves, and folds. Chromatin is variably granular and one or
more well-defined nucleoli are evident. In the T-cell neoplasms,
pleomorphism of the malignant elements may be greater than
in the B-cell lymphomas. There may be an admixture of small,
medium-sized, and large neoplastic cells. These last may have
huge macronucleoli and relatively voluminous cytoplasm. Neu-
trophils and granular debris are present in the background, at
times intimately mixed with the neoplastic cells. In this setting
of a polymorphic cell population, the diagnosis of lymphoma
may be very challenging.
The
cytologic differential
diagnosis
includes
the
more
common adenocarcinoma. As the lymphoma probably will have
ulcerated the mucosa, regenerative changes within benign epi-
thelial cells (reparative atypia) may add to the confusion. Both
focal and diffuse nodular lymphoid hyperplasia may involve
the duodenum. If there are defects in the overlying mucosa, the
brush may sample the reactive lymphoid cells. A polymorphic
appearance of lymphoid cells with round smooth and irregular
nuclear contours and a wide spectrum of diameters are present
(Fig. 14.27). A helpful clue is the presence of tingible body
macrophages mixed with the lymphocytes.
Giardia
may also be
present. Rarely, granulocytic sarcoma may present in the duo-
denum. Smears contain cells representing all maturation stages
of segmented leukocytes with a large proportion of blasts; the
recognition of eosinophilic elements may be a helpful tip.
Metastatic Tumors
Metastases may occur to any portion of the alimentary tract.13,106
Although malignant neoplasms arising almost anywhere in the
body may spread to the tract, the more frequent ones include
melanoma and carcinomas of the breast, ovary, and lung. Only
rarely have these neoplasms been described in endoscopic cyto-
logic preparations. According to Kadakia and co-workers, biop-
sies and brushings are complementary, although both modalities
are often positive.106
397
previous page 393 ComprehensiveCytopathology 1104p 2008 read online next page 395 ComprehensiveCytopathology 1104p 2008 read online Home Toggle text on/off