Percentage of sarcomatoid histology is associated with survival in renal cell carcinoma: Stratification and implications by clinical metastatic stage.

PURPOSE: Sarcomatoid dedifferentiation in renal cell carcinoma (RCC) represents an aggressive histology where degree of sarcomatoid histology (SH) may impact prognosis for cM0 and cM1 patients. We aimed to evaluate the association of percentage of SH with survival. MATERIALS AND METHODS: Patients ≥18 years old diagnosed with RCC with any degree of SH after nephrectomy were included (2005-2020) from a single-center. Associations of degree of SH and cM stage with overall survival (OS) and recurrence-free survival (RFS) were evaluated by Kaplan-Meier curves and Cox proportional hazards regression. RESULTS: One hundred twenty-eight patients were included with 80 (62.5%) cM0 and 48 (37.5%) cM1. cM1 patients were more likely to be male with higher clinical T stage (P = 0.001) than cM0, but a similar proportion had ≥20% SH (47.9% vs. 42.5%, P = 0.55). With median 19.4 months follow-up, SH was associated with worse OS per 10% increase (hazard ratio [HR] 1.12 [95% confidence interval {CI} 1.03-1.23], P = 0.009) and a ≥20% cutoff (HR 2.87 [95% CI 1.27-6.47], P = 0.01). Patients with cM0 disease and <20% SH had better 2-year OS (81.4%) compared to cM0 and ≥20% SH (44.8%) or cM1 patients who received nephrectomy (54.8%). Tumor size was also an independent predictor. Sites of distant metastasis and lines of therapy were similar for metachronous and synchronous patients. SH stratified 2-year RFS (cM0: 70.2% for <20% SH vs. 32.1% for ≥20% SH). CONCLUSIONS: SH in RCC is independently associated with OS and RFS. Patients who are cM0 with any SH may be candidates for adjuvant immunotherapy while those with ≥20% SH likely carry micrometastatic disease and should receive closer surveillance.

Rare primary pulmonary angiosarcoma with aberrant neuroendocrine differentiation.

Angiosarcomas are aggressive, malignant endothelial cell tumors derived from the vascular or lymphatic epithelium. Angiosarcomas makes up less than 1% of all soft tissue sarcomas. Primary pulmonary angiosarcoma is a rare tumor that most commonly presents as metastatic disease and carries a grim prognosis. The disease rarity and low index of suspicion make the diagnosis problematic. In this report, we present a case of primary pulmonary angiosarcoma with aberrant neuroendocrine differentiation. The diagnostic images, pathology and management strategy are discussed in this case with overall longer survival. The unique neuroendocrine pathologic subtype may contribute to the overall longer survival, however, there are only a few limited cases published. Further recognition and investigation of primary pulmonary angiosarcoma with aberrant neuroendocrine differentiation is warranted to further characterize diagnostic markers, determine more effective treatment strategies, and establish a possible link to improved survival.

The Conundrum of Diagnosing Cutaneous Composite Lymphoma in the Molecular Age.

INTRODUCTION: Cutaneous composite lymphoma (CCL) is extremely rare. When 2 potentially distinct lymphoid lesions occur at one skin site, distinguishing between one neoplastic clone and a secondary reactionary lymphoid response versus a second neoplasm is difficult. In this study, we describe a unique case of CCL along with a review of reported cases in literature to identify clues and discuss issues that are relevant to the diagnosis of CCL. DESIGN: Review of a CCL case from our institution and a systematic review of reported cases of CCL in the literature. RESULTS: A total of 18 studies describing 22 cases and a case report from our institution are included. The mean age at diagnosis was 68 years. Most cases herein presented with multiple skin lesions (67%) and reported a history of immune suppression (76%). Nineteen cases (83%) had a combination of T-cell and B-cell neoplasms, whereas the remaining cases had 2 distinct B-cell clones. Clonal differentiation was confirmed based on morphology and immunohistochemistry in all cases, and by polymerase chain reaction studies in 19 cases. Complete remission was achieved in only one quarter of reported cases. CONCLUSION: Diagnosing CCL can be challenging because accurate differentiation of 2 or more clonal populations at 1 site is tedious. A stepwise approach and integration of clinical, morphologic, immunohistochemistry, and molecular data along with an understanding of the prognosis of the lymphomas in question is essential for an accurate diagnosis and necessary because of therapeutic and prognostic implications.