Sinonasal Neuroendocrine Carcinoma: 15 Years of Experience at a Single Institution

Objectives Sinonasal neuroendocrine carcinomas (SNECs) are among the rarest paranasal sinus cancers. Consensus guidelines for therapy are difficult to develop due to limited data regarding the natural history and successful treatment of these tumors. This study presents 15 years of experience treating SNEC at a single institution and a review of the literature. Design Retrospective review. Setting Academic medical center in the United States. Participants Patients diagnosed with primary SNEC. Main Outcome Measures Overall survival. Results Thirteen patients were identified and included. Overall estimated survival was 74.6% at 5 years. Ten of 13 (76.9%) patients were diagnosed with high-grade neuroendocrine carcinoma and three (23.1%) with intermediate or low grade. All three patients with low- or intermediate-grade cancer survived more than 10 years from their initial diagnosis (median survival: 11.6 years) and are currently alive. The four patients who died had high-grade carcinoma, and estimated overall 5-year survival for all patients with high-grade carcinomas was 65.6%. Five patients, all with high-grade carcinoma, of seven who completed primary chemoradiation therapy (CRT) required salvage resection, and 60% are alive without disease. Conclusion This cohort has a higher overall rate of survival than many recent case series and reviews. There is consensus that multimodal therapy is preferred over monotherapy, but approaches to treatment vary widely. Our approach of surgical resection as primary therapy for low-grade tumors and primary CRT for high-grade SNEC has been successful, and could indicate hope for improved survival among these patients.

Dysregulation of PI3K/Akt/PTEN Pathway in Canine Mammary Tumor

The PI3K/Akt/PTEN axis is one of the most important signaling pathways in tumorigenesis. Recently, mutation of PIK3CA has been highlighted due to the similarities of mutational hotspots in both dogs and humans. PIK3CA H1047R (c.3140A > G) has been discovered as the most common mutational hot spot in canine mammary tumor in recent studies, while the feature of PIK3CA-mutated canine mammary tumor is obscure. Methods: A total of 83 mammary samples classified as normal (n = 13), adenoma (n = 25), low-grade carcinoma (n = 21), and high-grade carcinoma (n = 24) were included in this study. Genomic DNA from each sample was extracted, amplified by conventional PCR, and analyzed through Sanger sequencing. Analysis for the expression of PIK3CA, Akt, p-Akt, and PTEN was performed by immunohistochemistry, and of Akt2 by RNA in situ hybridization. Results: PIK3CA H1047R mutation was detected in 14.3% (10/70) of tumor samples. Dysregulation of p-Akt, Akt2, and PTEN was observed in mammary tumor samples, but only PTEN dysregulation was associated with PIK3CA H1047R mutation. Conclusions: The present study showed that dysregulation of components in the PI3K/Akt/PTEN pathway is a feature of canine mammary tumors, but this dysregulation is not directly correlated to the PIK3CA H1047R mutation except for PTEN expression.

Dealing with prostate cancer? Don’t let histiocytic lesions fool you!

Background Prostate adenocarcinoma has well known benign mimickers. Histiocytic proliferations usually impose differential diagnosis with high-grade component of acinar adenocarcinoma (Gleason pattern 5). Case presentation We present herein three cases of histiocytic lesions of the prostate in which accurate recognition avoided inappropriate upgrading (malakoplakia associated with prostate adenocarcinoma, two cases) and false positive diagnosis at biopsy (xanthoma with signet ring morphology). Conclusion In needle biopsies, pathologists should have a low threshold to perform immunostains when considering a differential diagnosis between high-grade carcinoma and a histiocytic lesion. In prostatectomy specimens, abrupt transition to solid areas in low and intermediate grade tumors should raise concern to exclude malakoplakia. PAS and von Kossa stains are inexpensive and a valuable tool to highlight typical Michaelis–Gutmann bodies.

Aberrant Diffuse Intense CD10 Expression In P16 Positive Undifferentiated Endometrial Carcinoma: A Diagnostic Dilemma

Introduction/Objective High-grade endometrial neoplasms frequently pose a diagnostic challenge on purely histologic evaluation due to their ambiguous morphologic features. High grade endometrioid adenocarcinoma, serous carcinoma, undifferentiated carcinoma, and a minority of sarcoma cases can present with a solid growth pattern. Methods We present a 59-year-old patient who underwent a hysterectomy and bilateral salpingo-oophorectomy for a biopsy proven FIGO grade 2 endometrial carcinoma. Results Grossly, the entire endometrial cavity was involved by a hemorrhagic tumor. Microscopic examination showed the entire specimen to be replaced by predominantly non-cohesive diffuse sheets of mitotically active, pleomorphic cells without any glandular, papillary, serous or clear cell features.The differential diagnosis included undifferentiated carcinoma, serous carcinoma, carcinosarcoma, stromal sarcoma and other tumors including high- grade lymphoma. By immunohistochemistry, the tumor cells showed variable positivity for CK7, EMA, CK19, CK18, CK8, AE1/AE3, pan-keratin, CAM5.2, CD56, synaptophysin, p53, cyclinD1 and with a high Ki-67 proliferation index of 80%. The tumor was diffusely/intensely positive for CD10 and P16 while being negative for ER, PR, PAX8, HPV, mesenchymal and lymphoid markers. While diffuse/intense CD10 positivity and ER/PR negativity raised a concern for stromal sarcoma component, the above phenotype confirmed an aggressive/high grade carcinoma. Diffuse/intense p53 and p16 expression raised a consideration of serous carcinoma, but morphology and absence of PAX-8 failed to support this diagnosis. Undifferentiated carcinoma of the endometrium is a high-grade carcinoma which has been recognized as a distinct entity with diffuse p16 and p53 positivity in the absence of PAX-8 and hormone receptors. Positive vimentin, along with a negative HPV, confirmed the endometrial rather than cervical origin of this neoplasm. Conclusion By reporting this case, we draw attention to the previously unreported diffuse intense CD10 expression in undifferentiated carcinoma of endometrium to avoid misdiagnosis with considerations that include stromal sarcoma.