Wu, Douglas

Pelvicalyceal invasion (PCI) is a relatively novel pT3a staging parameter for renal cell carcinoma (RCC) nephrectomies. While interobserver reproducibility staging studies of sinus/vascular invasion in RCC exist, a similar evaluation for PCI has not been performed. Moreover, in our experience, there is also diagnostic variability in how pathologists interpret PCI. Herein, we explore interobserver reproducibility among genitourinary (GU) pathologists. Twenty hematoxylin and eosin-stained digitized slides from RCCs (all grossly approaching the renal pelvis) were distributed to 31 GU pathologists to classify each as PCI or not PCI based on their respective clinical practices; slides with concomitant sinus/fat/vascular invasion were excluded. Slides were then evaluated for the following 4 morphologic features: tumor abutting renal pelvis, tumor pushing/indenting into the renal pelvis, polypoid configuration of tumor into the renal pelvis, and tumor eroding through renal pelvic urothelium. Interobserver reproducibility was assessed, and the morphologic features were correlated with PCI. Relationships between pathologists’ interpretations, morphologic features, and PCI were evaluated using hierarchical clustering. Although the diagnosis of PCI was relatively uniform with a majority agreement (>67%) reached in 16/20 slides, overall interobserver reproducibility was only moderate (kappa=0.601). While all 4 morphologic features were sensitive for PCI, polypoid configuration of the tumor into the renal pelvis and the tumor eroding through the renal pelvic urothelium were most specific (90%, 100%, respectively). Although we show general consensus among genitourinary pathologists on PCI assessment, clarifying the diagnostic guidelines with specific criteria should be included in pathologic staging systems.

AimsCompared to lymphovascular invasion (LVI), hilar soft tissue invasion (HSTI) is a relatively novel pT2 staging parameter in testicular germ cell tumours (GCT), associated with metastasis at the time of diagnosis and a risk factor for disease relapse. Given diagnostic variability in how pathologists interpret HSTI, herein we explore interobserver reproducibility among genitourinary (GU) pathologists.MethodsTwenty haematoxylin and eosin‐stained digitized slides from testicular GCTs were distributed to 30 GU pathologists to classify each as HSTI or not HSTI based on their respective clinical practices; slides with concomitant LVI were excluded. Slides were then evaluated for the following morphologic features: tumour invasion beyond prominent hilar vessels, tumour invasion beyond the rete, tumour invasion beyond the level parallel to hilar adipose tissue and tumour within (directly touching) hilar adipose tissue. Interobserver reproducibility was assessed, and the morphological features were correlated with HSTI. Relationships between pathologists' interpretations, morphological features and HSTI were evaluated using hierarchical clustering.ResultsAlthough the diagnosis of HSTI was relatively uniform with a majority agreement (>67%) reached in 17/20 slides, overall interobserver reproducibility was only moderate (kappa = 0.50). Morphological features such as invasion beyond the level parallel to hilar adipose tissue and invasion into fat were more sensitive and specific for HSTI, while features such as invasion beyond hilar vessels and invasion beyond rete were less useful.ConclusionsThese findings suggest that more specific defined diagnostic criteria for testicular GCT HSTI are needed.

Background: Atypical fibroxanthoma (AFX) is a dermal-based, low-grade neoplasm with no specific lineage of differentiation. The occurrence of AFX with osteoclast-like giant cells is exceptionally rare. Less than 20 cases have been reported in the literature. Case Presentation: A 77-year-old man with a medical history of multiple basal and squamous cell carcinomas of the skin, presented with a progressively growing erythematous nodule on the sun-damaged right central parietal scalp. A shave biopsy showed a dermal spindle cell proliferation accompanied by numerous osteoclast-like multinucleated giant cells and predominant atypical mitotic figures. The immunohistochemical staining showed a diffuse positive staining for CD68 and SMA, patchy staining for CD10, and negative staining for SOX-10, pan-cytokeratin, CK5/6, S100, CD34, and desmin. The tumor was completely excised with negative margins. A subsequent follow-up over a period of 13 months showed no recurrence. Conclusion: Distinguishing AFX with osteoclast-like giant cells from both malignant and benign skin lesions with osteoclast-like giant cells is crucial. Although AFX tumors display worrisome malignant histologic features, most cases have a favorable prognosis with a local recurrence rate below 5% and exceedingly rare metastasis.