Early onset, development and histological features of gastric signet-ring cell carcinoma.

Objective: To explore the early onset, development and histological features of gastric signet-ring cell carcinoma (SRCC). Methods: Three hundred and sixty-two patients with differentiated adenocarcinoma with signet-ring cells were enrolled. Histomorphological and immunohistochemical features and patterns of the specimens were observed in detail. Results: Infection of the gastric mucosa, especially by Helicobacter pylori, can cause massive cell proliferation and transformation in the deep gastric foveola, the isthmus of the gastric gland, and the proliferative zone of the upper neck of the gland. Signet-ring-like heterocysts monoclonally proliferated after the redifferentiation and reproliferation, extending horizontally along the gastric foveola. Gastric foveolar-type SRCC grew infiltratively into the lamina propria of the mucosa and the submucosa, signet-ring cells could differentiate into undifferentiated adenocarcinoma with signet-ring cell differentiation, mucinous adenocarcinoma with signet-ring cell differentiation, gastric adenocarcinoma with signet-ring cell differentiation, and fundus gland adenocarcinoma with signet-ring cell differentiation. Conclusion: Early SRCC developed from the proliferative zones of the fundus of the gastric foveola and the neck of the gastric gland, growing horizontally along the gastric foveola. It developed into gastric adenocarcinoma with signet-ring cell differentiation after reproliferation and retransformation in the mucosa.

Signet Ring Cell Differentiation in Salivary Duct Carcinoma with Rhabdoid Features: Report of Three Cases and Literature Review.

Salivary duct carcinoma with rhabdoid features (SDCRF) is a rare salivary tumor with poor prognosis and is proposed as a salivary counterpart of pleomorphic lobular carcinoma of the breast (PLCB). Here, we report three cases of SDC with rhabdoid features (SDCRF) mimicking PLCB. Pleomorphic adenoma (PA) component was accompanied in all the cases confirming carcinoma ex PA. One patient had frequent rhabdoid features and showed invasive growth into the surrounding tissue. The other two patients had intracapsular tumor but with rhabdoid features. The patients with intracapsular SDCRF survived for > 5 years after surgery with no evidence of recurrence, whereas the patient with extracapsular SDCRF died 10 months after biopsy, and autopsy revealed disseminated metastasis to the central nervous system. Histologically, tumor cells in all three cases resembled PLCB, with a discohesive appearance, abundant cytoplasm, enlarged hyperchromatic nuclei, and similar immunohistochemical profiles, namely loss of membranous E-cadherin, obscured expression of membranous ß-catenin, diffuse positivity of androgen receptor, gross cystic disease fluid protein-15, mitochondrial adenosine triphosphate synthase subunit ß, MUC1, and INI-1. Estrogen and progesterone receptors were negative, and HER2 immunoreactivities were variable. The tumor cells of extracapsular invasive SDCRF exhibited higher MIB-1 labeling index and more frequent intracytoplasmic lumina than those of intracapsular SDCRF. Ultrastructurally, rhabdoid cells contained intracytoplasmic lumina with microvillous structure, analogous to those reported in PLCB. No intracytoplasmic intermediate filament aggregation was observed. These observations indicate that SDCRF is a salivary counterpart of PLCB and under signet ring cell differentiation.

Primary mucinous carcinoma of thyroid gland with prominent signet-ring-cell differentiation: a case report and review of the literature.

PURPOSE: This study reports a case of primary mucinous carcinoma of the thyroid gland with signet-ring-cell differentiation, and reviews the literature to evaluate its real incidence and the prognosis of these patients. PATIENTS AND METHODS: A 74-year-old Chinese woman, presenting with a mass in the right lobe of thyroid gland, came to the hospital. Computed tomography revealed a mass in the right lobe of the thyroid gland, accompanied with right neck lymphadenectasis and airway deviation caused by tumor compression. Thyroid imaging suggested a thyroid malignant tumor and suspicious lymph node metastasis. Histologically, the tumor was characterized by the tumor cells arranged in small nests or trabeculae with an abundant extracellular mucoid matrix. The tumor cells formed diffuse invasion among thyroid follicles. In the peripheral regions, prominent signet-ring-cells formed a sheet-like structure and extended into the extrathyroidal fat tissue. The tumor cells were diffusely positive for thyroid transcription factor-1 (TTF-1) and PAX8, while they were focally positive for pan-cytokeratin (AE1/AE3) and weakly expressed thyroglobulin. RESULTS: Based on the histological features and immunohistochemical profile, a diagnosis of primary mucinous carcinoma of the thyroid gland with signet-ring-cell differentiation was rendered. CONCLUSION: Using a panel of immunohistochemical markers may be helpful for differential diagnosis and for determining whether the tumor is primary or not.