ABSTRACT
Context: Extragastrointestinal stromal tumors (EGIST) are extremely uncommon neoplasm. To the best of our knowledge, only one retroperitoneal EGIST case has been reported in Oncolgy, in 2005（PubMed search result). Case Report: A 67-year old female patient presented with epigastric discomfort, dyspepsia, and anemia. Ultrasonographic examination of the abdomen showed the location of the tumor was between the tail of the pancreas and the spleen (retroperitoneal), it was variable in size of 12.3cm×7.2cm×14cm. Color Doppler Flow Imaging (CDFI) showed no flow signals with arterial-venous doppler spectrum in the masses．Contrast-enhanced computed tomography of the abdomen revealed a heterogeneously enhancing mass (8.23cm×14.2cm) and abundant blood supply of the tumor. The patient underwent gastroscopes-guided biopsy from the fundus of stomach for pathologic diagnosis and the result indicated chronic superficial gastritis. A complete gross excision was performed. Retroperitoneal tylectomy, left hepatic lobectomy, enterolysis, and liver biopsy were performed. Two weeks post operation, the patient was discharged without any postoperative problems. The final diagnosis of retroperitoneal EGIST was confirmed by histopathological examination and immunohistochemical findings (CD117 positivity). Conclusion: We report a very rare case of retroperitoneal EGIST. Although the Ultrasonographic examination, computer tomography and endoscopy examination did not confirm the final diagnosis, they are complemented to each other in order to identify the exact location of the tumor. EGIST should be considered in the differential diagnosis of solid masses of abdomen on cytology and immunohistology.
ABSTRACT
<p><b>OBJECTIVE</b>To study the clinicopathologic features, immunophenotypes and differential diagnosis of thyroid carcinoma showing thymus-like differentiation (CASTLE).</p><p><b>METHODS</b>The clinical and pathologic features of 8 cases of CASTLE were reviewed. Immunohistochemical study was performed using a panel of antibodies. In-situ hybridization for Epstein-Barr virus-encoded RNA (EBER) was also carried out.</p><p><b>RESULTS</b>There were altogether 4 males and 4 females. The age of the patients ranged from 25 to 57 years (mean = 48.8 years). All of them presented with painless mass at the anterior neck. Two patients also complained of hoarseness of voice. On CT scan, the tumor had a low density with contrast enhancement. Seven cases were located in the mid to lower pole and the remaining one in the upper pole of thyroid gland. Four cases were relatively circumscribed. The other 4 cases showed evidence of extrathyroidal invasion. Grossly, the tumor had a nodular or lobulated appearance and was gray-white in color, with a mean diameter of 4.3 cm. Microscopically, the tumor was infiltrative and consisted of islands, nests or lobules of epithelial cells separated by thick fibrous septa. The fibrous stroma showed various degree of lymphoplasmacytic infiltration, resulting in a prominent lymphoepithelioma-like pattern in 3 cases. Two cases showed squamoid differentiation, mimicking thymic Hassall corpuscles. Immunohistochemically, the tumor was consistently positive for cytokeratins, CD5, bcl-2, p63 and CD117. CEA was variably expressed. The staining for thyroglobin and TTF1 was negative. There was no labeling for EBER in all the cases. Two patients experienced local recurrence at 22 months and 12 years after surgery, respectively. They were treated with re-resection. All patients remained well on follow up. The duration of follow up ranged from 4 to 55 months.</p><p><b>CONCLUSIONS</b>CASTLE is a low-grade thyroid carcinoma with the morphologic features and immunophenotypes overlapping with those of thymic carcinoma. Awareness of this rare entity is important to both the pathologists and clinicians.</p>