The prognostic relevance of histologic subtype in appendiceal adenocarcinoma

BackgroundThe aim of this population-based study was to determine the prognostic value of the histologic subtypes mucinous (MAC), non-mucinous (AC) and signet ring cell (SRCC) adenocarcinoma among patients with appendiceal cancer.Methods and materialsData from the Netherlands Cancer Registry (NCR) of patients with primary appendiceal adenocarcinomas with MAC, AC and SRCC histologic subtype, diagnosed between 2001 and 2015 were used (n = 675). To categorize patients according to the recent histopathological classification, the NCR was linked with the Dutch Pathology Registry (PALGA). Log-rank tests and Kaplan-Meier analyses were performed to estimate overall survival (OS), and the cox proportional hazards model was run to identify prognostic factors.ResultsAC was the most frequently encountered histologic subtype (50.9%), followed by MAC (35.8%) and SRCC (13.3%). In locoregional disease, histologic subtype was not a prognostic factor for OS with 5-year survival rates for patients with AC, MAC and SRCC of 60.0%, 60.5% and 69.6% respectively (p = 0.68). Metastatic disease was more common in SRCC (53.8%) than in MAC (38.8%) and AC (23.4%) (p < 0.0001). Median OS for patients with metastatic disease was 12.6, 27.7 and 18.2 months in AC, MAC and SRCC respectively (p < 0.005). MAC was associated with higher survival compared to AC (HR 0.48, 95%CI 0.34–0.69). In subanalyses, MAC was only a positive prognostic factor compared to AC in patients with peritoneal metastases (HR 0.42, 95%CI 0.28–0.62).ConclusionHistologic subtype had no prognostic relevance in locoregional or systemic metastatic disease in appendiceal adenocarcinoma. In peritoneal metastases, mucinous histologic subtype was a favorable prognostic factor, compared to non-mucinous and signet ring cell subtype.     

Primary diagnosis of angiosarcoma by fine needle aspiration: Lessons learned from 3 cases

Angiosarcomas are rare malignancies arising from cells of endothelial origin and are aggressive sarcomas that can occur in any anatomic site. They are reported to have predilection for the scalp, extremities and breasts. The incidence of these tumors is increasing, which has been suggested to be attributable to the growing use of radiotherapy to treat breast and other malignancies. There is currently limited literature describing the primary cytologic diagnosis of angiosarcoma on fine needle aspirate material. We describe the findings of three cases of angiosarcoma diagnosed by fine needle aspiration. Our three cases offer distinct radiologic, clinical and cytopathologic points‐of‐view: a thyroid angiosarcoma, a mediastinal angiosarcoma and a skin angiosarcoma. The cytomorphology of angiosarcoma is characterized by large highly atypical spindle to epithelioid cells with abundant cytoplasm in dispersed single cells or loose aggregates. The nuclei are large and pleomorphic with vesicular chromatin and prominent nucleoli. Mitoses are readily identified. The background can be bloody and/or necrotic. Occasional intracytoplasmic lumens are a helpful morphologic feature suggesting vascular differentiation. HHV‐8 immunostaining may aid in the differential diagnosis with Kaposi sarcoma while epithelioid hemangioendothelioma can be distinguished based on morphologic features. Given the metastatic potential and high mortality rate associated with these tumors, this entity is an important consideration in the contexts herein described.