Artifactual signet-ring-like cells in endoscopic biopsy of gastric lymphoma
ABSTRACT To describe the morphologic characteristics of neoplastic lymphocytes with shrinkage artifact of cytoplasm secondary to formalin fixation and/or necrosis, which simulate carcinoma signet-ring cells in endoscopic biopsy.
Sixty-eight endoscopic biopsies with gastric lymphoma were studied retrospectively. We selected those biopsies in which artifactual signet-ring-like cells were the main histologic feature and were confused with adenocarcinoma. Mucin stains were performed on all specimens. To support their B-cell phenotype, immunohistochemical study with leukocyte common antigen (CD45), pan B-cell marker L26, keratin, and carcinoembryonic antigens were performed. The diagnosis of gastric lymphoma was confirmed in gastrectomy specimens.
The distinction between poorly differentiated adenocarcinoma and gastric lymphoma in endoscopic biopsies is sometimes difficult owing to the morphologic similarities that these neoplasias can share and the small amount of tissue obtained by this technique. An additional factor that may contribute to this confusion is the presence of artifactual lymphocytes resembling signet-ring cells.
Three (4%) of the 68 biopsies showed artifactual lymphocytes in most or all the tissue fragments that resembled carcinoma signet-ring cells. These biopsies showed massive substitution of gastric glands by lymphomatous infiltrate. Crush artifact of neoplastic lymphocytes was observed in many fields. Necrosis, inflammation, and epithelial erosion were prominent findings. Mucin stains were negative, and immunohistochemical studies were positive for leukocyte common antigen and B-cell marker L26 in two of the three cases.
We conclude that if a poorly differentiated neoplasm consistent with signet ring adenocarcinoma is found in an endoscopic biopsy with artifactual changes, the diagnosis of gastric lymphoma must be excluded using histochemical and immunohistochemical studies.
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ABSTRACT: Goblet cells in the lower respiratory tract are metaplastic bronchial epithelial cells usually associated with asthma or chronic bronchitis. Goblet cells acquire their name by a tendency to distend with mucus, with subsequent distortion in cell shape. Due to similarity of shape, metaplastic goblet cells and signet ring cells can be easily confused in cytologic samples. A 55-year-old male with a history of gastrointestinal adenocarcinoma underwent brushing, washing and biopsy of a bronchial lesion. The bronchial wash and brush samples showed a very cellular specimen, with large aggregates of distended columnar cells. These were arranged in long strips, thick bundles and occasional three-dimensional aggregates. Some aggregates contained numerous rounded cells with markedly distended cytoplasm. The rounded cells were slightly larger than the distended columnar cells. These cells had a relatively large but innocuous-appearing nucleus displaced to the periphery of the cell. The corresponding bronchial biopsy revealed signet ring adenocarcinoma, presumably metastatic from the gastrointestinal primary. Signet ring adenocarcinoma, either primary or metastatic, can be difficult to diagnose in cytologic and histologic specimens. There are numerous mimics of signet ring cells, both benign and neoplastic. In respiratory cytologic specimens, one of the benign imposters is goblet cell metaplasia.Acta cytologica 01/1999; 43(6):1108-12. DOI:10.1159/000331362 · 1.56 Impact Factor
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ABSTRACT: We describe 5 patients (mean age, 50 years; all had uterine bleeding) whose routine endometrial biopsy and curettage specimens contained prominent signet-ring cells. Each specimen contained loose aggregates of signet-ring cells scattered within the endometrial stroma that were characterized by peripherally displaced, small, uniform nuclei with indistinct nucleoli and showed no mitotic activity. The central portion of the cytoplasm was occupied by single or multiple cytoplasmic vacuoles. In all cases, the signet-ring cells were reactive for vimentin and negative for epithelial membrane antigen and cytokeratin. Four cases were focally positive for muscle-specific actin or smooth muscle actin and negative for CD68, Mac387, periodic acid-Schiff, mucicarmine, and alcian blue. In these 4 cases, the surrounding endometrial stroma showed decidual changes, and the signet-ring cells demonstrated a morphologic continuum with more typical decidualized stroma. As such, the signet-ring cells in these cases were vacuolated, decidualized endometrial stromal cells. In the remaining case, the vacuolar contents of the signet-ring cells were periodic acid-Schiff-positive and resistant to diastase predigestion, and the cells reacted with Mac387 and CD68. The surrounding stroma showed no decidual reaction. Thus, the signet-ring cells in this case were of histiocytic differentiation. Endometrial stroma occasionally may contain nonneoplastic signet-ring cells that closely mimic adenocarcinoma. At least 2 directions of differentiation, decidual and histiocytic, are possible.American Journal of Clinical Pathology 03/2001; 115(2):249-55. DOI:10.1309/RL5H-VC5D-9WE2-X71H · 2.51 Impact Factor
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ABSTRACT: We report a case in a 74-year-old woman of collecting-duct carcinoma of the kidney with prominent signet ring cell features. Grossly, the tumor measured 5.5 cm in greatest dimension, occupied the entire upper pole of the kidney, and was well circumscribed. Microscopically, it displayed a predominant tubulopapillary pattern of growth with a hyalinizing stroma. The tumor tubules were lined by a single layer of cells with large, pleomorphic nuclei, some of which had a hobnail appearance. Large intracytoplasmic vacuoles with compression of nuclei (signet ring cells) were present throughout the tumor. Alcian blue, mucicarmine, and periodic acid-Schiff stains failed to identify intracellular mucin or glycogen in the signet ring cells. Enlarged cells with intracytoplasmic vacuoles were also noted in the adjacent collecting ducts. The tumor cells were immunohistochemically positive for cytokeratin including cytokeratin 7, CAM 5.2, AE1/3, and 34 beta E12, vimentin, peanut lectin agglutinin, and Ulex europaeus agglutinin. Electron microscopy revealed that the intracytoplasmic vacuoles were due to intracellular edema. To the best of our knowledge, this is the first reported case of renal collecting-duct carcinoma with prominent signet ring cell features.Modern Pathology 07/2001; 14(6):623-8. DOI:10.1038/modpathol.3880361 · 6.19 Impact Factor