Inflammatory pseudotumor of the colon.

Inflammatory pseudotumor refers to a nonmalignant or low-grade neoplastic lesion characterized by the presence of spindle-cell proliferation with abundant inflammatory cells. Lung and orbit are the most frequent sites of occurrence, but the lesions may originate in nearly every site in the body, including the abdomen. We present a rare and interesting case of inflammatory pseudotumor of the colon in a 21-year-old male who presented to the emergency room with abdominal pain.

A Case of Appendiceal Adenocarcinoma with Clinical Benefit from FOLFOX and Bevacizumab.

A 44-year-old woman presented with lower abdominal pain and bilateral ovarian masses on ultrasound. Exploratory laparotomy revealed extensive peritoneal and intra-abdominal disease and an abnormal appendix. Bilateral salpingo-oophorectomy, infracolic omentectomy, ileocolic resection and primary anastomosis were performed. Final pathology revealed a primary appendiceal adenocarcinoma, poorly differentiated, of signet ring cell type. CT scan postoperatively revealed gross residual disease. The patient was treated with FOLFOX chemotherapy combined with bevacizumab. Repeat CT scan showed a decrease in residual disease and the patient clinically improved. After her treatment has been continued for 13 months, she remains clinically well and her CT scan shows sustained disease stability. Disseminated appendiceal carcinoma is generally considered to be refractory to 5-FU-based chemotherapy and, to our knowledge, this is the first reported case of a patient with appendiceal adenocarcinoma demonstrating clinical benefit and sustained stability of disease with combination chemotherapy plus bevacizumab.

Mixed epithelial and stromal tumour (MEST) of the kidney: report of 14 cases with male and PEComatous variants and proposed histopathogenesis.

AIMS: This article adds new cases and variants of MEST with discussion of the histopathogenesis. METHODS AND RESULTS: Fourteen MEST were originally diagnosed as cystic nephroma which represents an incidence of 1.6% of renal neoplasms in adults. In females, the stromal component showed areas of müllerian differentiation with positive immunoreactivity for oestrogen (ER) and progesterone receptors (PR) and CD10. Immunoreactivity for HMB45 was identified in a single case having a leiomyomatous appearance. The epithelial component displayed features of müllerian epithelium and reactive renal tubular cells. In two male cases, MEST consisted of fibrous and smooth muscle stroma and cysts lined only by reactive renal tubular cells. Immunoreactivity for ER and PR was focal and weak. CONCLUSIONS: MEST represents a tumour developing from müllerian-like stromal cells in the kidney. The neoplastic stroma encroaches on the renal tubules and has the potential to stimulate the growth of the renal tubules by contact, with development into cysts. Furthermore, the müllerian stroma likely induces the renal tubules to differentiate into müllerian-like epithelium. Melanocytic differentiation of the stroma may occur which represents the PEComatous variant. MESTs in males were histopathologically slightly different from those in females due to the different hormonal milieu.

Calretinin: an immunohistochemical marker for the normal functional endometrial stroma and alterations of the immunoreactivity in dysfunctional uterine bleeding.

Calretinin has been identified in the central nervous system, in various endocrine and mesothelial cells, and is often used as an immunohistochemical tool in the pathologic diagnosis. We have recently observed its presence in the endometrial stromal cells (ESC) of the normal functionalis (FL). Endometrial tissue from various physiologic and pathologic conditions was submitted for immunostaining for calretinin. For each condition, two to ten samples were tested. Calretinin displayed a strong cytoplasmic and occasionally nuclear reactivity for ESC of the normal FL in all physiologic phases of the normal menstrual cycle except for the breakdown period. Reactivity was limited in the superficial zone of the FL in proliferative phase, and was extensive in all stages of secretory phase. The ESC of the basilis layer, postmenopausal women, endometriotic and adenomyotic tissue, endometrial polyps, hyperplasia, carcinoma, and ESC neoplasms were not reactive for the marker. In endometrial specimens from patients with dysfunctional bleeding, there were varying degrees of decrease in reactivity in a patchy pattern. We demonstrated for the first time that calretinin reactivity of the ESC is strong and diffuse in a zonal pattern in the normal FL of the normal cycling endometrium. In endometrium with dysfunctional bleeding, postmenopausal, ectopic, hyperplastic, and neoplastic endometria, the ESC displayed focally decreased to negative reactivity. Calretinin can be used as a marker for normally functional ESC. Further study is necessary to investigate the mechanism and the role that calretinin plays in the physiologic cyclic changes of the endometrium.