Paper # 001 Versión en Español Versión en Español

Adenocarcinoma of the Stomach after Therapy for Lymph Nodes Low Grade Lymphoma

Marcial Garcia-Rojo, Jesús González, Ana Morillo, Jesús Martín

[Title] [Introduction] [Materials and Methods] [Pictures] [Discussion] [Bibliography]

Materials and Methods

Pictures


RESULTS

Axillary Lymph Node
The pathological examination of the axillary lymph node biopsy showed macroscopically a 2.5 x 2.5 x 1.5 cm lymph node with an smooth and homogeneous cut surface. The histological examination revealed an almost complete effacement of the architecture of the lymph node, only sparing some marginal zones. This effacement was due to a neoplastic diffuse proliferation of small lymphocytes with eccentric nuclei with visible nucleoli and a moderate amount of cytoplasm, which showed frequent PAS positivity. Immunohistochemically, neoplastic cells were found to be positive with the Common Leukocyte Antigen (CLA) (CD54A), L-26 (CD-20) and Kappa light chains immunohistochemical markers. They were negative for Kappa light chains and UCHL-1 (CD45RO), although there were frequent accompanying non-neoplastic small UCHL-1 positive lymphocytes. The neoplasm was diagnosed as a low grade B-cell non Hodgkin lymphoma type lymphoplasmacytoid (immunocytoma).

Stomach
The pathological examination of the gastrectomy specimen showed an infiltrated aspect of the gastric mucosa and muscular layer in both the fundic area and the antrum, with a more extensive involvement of the lesser curvature. Histologically the neoplasm was diffuse and composed of malignant individual cells and small groups with abundant intracytoplasmic mucin., often producing a signet-ring aspect. In about a 10 % of the tumor, there were lakes of extracellular mucin con scarce amount of cells often arranged in small sheet. These mucinous areas affected mainly the muscular layer of the stomach. The neoplastic cells reached the serous surface and infiltrated the fundic area and part of the antrum and cardiac zones, but spared the proximal and distal resection margins. There were metastases from this tumor in four of seven lymph nodes isolated in the lesser curvature and also in nine of thirteen lymph nodes isolated from the greater curvature and omentum.

Collision of lymphoma and adenocarcinoma in lymph nodes
Interestingly, all the lymph nodes isolated in the surgical specimen were affected by a low grade non Hodgkin lymphoma type immunocytoma, with the same characteristics of the one diagnosed six months earlier. So, in thirteen lymph nodes we could observe a collision of the lymphoma and the metastasis of the adenocarcinoma. The lymphoma in these nodes only spared the marginal sinus, were a great amount of metastatic signet ring adenocarcinoma cells were located, frequently extending to the surrounding perinodal adipose tissue. The differentiation of adenocarcinoma cells from lymphoid cells were accentuated by the PAS and Colloidal Iron Stains, that stained strongly signet ring adenocarcinoma cells.

The immunohistochemical study of these two neoplasms revealed that the lymphoid tumor had the same characteristics as the lymphoma diagnosed six months earlier. Meanwhile, the adenocarcinoma cells were strongly positive with cytokeratins 8, 18 and 19 and CEA, and negative with LCA and the rest of lymphoid markers previously mentioned.

Spleen
The splenectomy specimen was 11 x 8 x 6.5 cm and weighed 282 g. At the cut surface a market whitish diffuse dotting cold be observed. No metastases were found neither in the spleen nor in the ten lymph nodes of the hilus, but all of these and the splenic white pulp were affected by a low grade non Hodgkin lymphoma type immunocytoma.


Materials and Methods

Pictures