The retinoblastoma family consists of the tumor suppressor nuclear phosphoprotein pRb/p105 and related proteins p107 and pRb2/p130. Recent immunohistochemical studies of the retinoblastoma family of proteins in lung and endometrial cancer and choroidal melanomas show a tight inverse correlation between the histologic grading in the most aggressive tumor types and pRb2/p130 expression. This led us to investigate the role of pRb2/p130 in salivary tumors. We studied the expression of pRb2/p130, p107, E2F4, p27, and PcNA by immunohistochemistry in a panel of 44 salivary gland tumors. We found a direct correlation between the cytoplasmic expression of pRb2/p130 and tumor grading and the presence of metastasis that was highly statistically significant (P < 0.001). Additionally, increased cytoplasmic pRb2/p130 expression was significantly correlated with a decreased probability of survival (P < 0.001). Interestingly, p107 nuclear expression showed a strong direct correlation when compared with the same variables. pRb2/ p130 showed the highest percentage of undetectable nuclear levels in the specimens examined and the tightest inverse correlation (P < 0.0001) with both the histologic grading and pCNA expression in malignant salivary tumors. Additionally, E2F4 showed an identical localization pattern as to that of pRb2/p130. These data suggests an important role for pRb2/ p130 in the pathogenesis and progression of certain salivary gland cancers.

Introduction: Endometriosis-associated intestinal tumours represent the malignant trasformation of gastrointestinal endometriosis. Clinical features are similar to a colon tumor with abdominal or pelvic pain, dyschezia or bloody stools. Intestinal occlusion or perforation have also been described as a first presentation. The diagnosis is often postoperative and it is based on specific immunohistochemical patterns (CK7+/CK20-). Case presentation: In this article we present a rare case of a woman with a malignant trasformation of an endometriotic lesion of the sigmoid colon, who underwent emergency surgery for intestinal occlusion. She underwent an exploratory laparotomy and Hartmann resection. The immunophenotypic analysis of the specimens revealed the following pattern: CK20-, CK7+, compatible with the diagnosis of endometrioid adenocarcinoma. Conclusions: Endometrioid carcinoma is a rare tumor, difficult to diagnose preoperatively because clinically it presents with symptoms similar to those of patients with sigmoid adenocarcinoma. A high index of suspicion in conjunction with careful histological and immunohistochemical examination (CK7, CK20, CDX2, CD10, ER, and PR) is important for establishing a correct diagnosis.