Renal neoplasia with papillary architecture involving the pelvicalyceal system

Fumarate Hydratase ( FH ) c.1431_1433dupAAA (p.Lys477dup) variant is not associated with FH protein deficiency and increased 2SC in two separate patients with renal neoplasia

“…This tumor showed constitutive expression of carbonic anhydrase IX, consistent with VHL inactivation in clear cell RCC (Figure 1e), retained expression of FH (Figure 1f), and no increase in 2SC (not shown). While molecular profiling of the tumor was not performed to exclude a compound heterozygous state, these cases support the findings of Zhang et al and suggest that "the heterozygous FH c.1431_1433dupAAA (p.Lys477dup) variant may not contribute to RCC" (Gupta et al, 2021;Zhang et al, 2020).…”

“…Importantly, both patients underwent germline testing due to identification of a renal tumor at a relatively young age. The first patient, previously reported by us, was a 13-year-old girl that presented with a 3.3 cm, pT1a (WHO grade 1) papillary renal neoplasm that lacked prominent nucleoli (Figure 1a), showed retained expression of FH (Figure 1b), and no increase in 2SC (Figure 1c) (Gupta et al, 2021). The second patient (40-year-old male) presented with a 3.9 cm, pT1a (WHO grade 1) clear cell RCC (Figure 1d), a histologic subtype unrelated to FH-deficient tumors, that underwent cryoablation.…”

Papillary Renal Cell Carcinoma With “Drop Metastasis” (Tumor Seeding) Involving the Distal Ureter

“…Involvement of the renal pelvicalyceal system ("defined as a renal tumor involving the urotheliumlined renal calyceal or renal pelvic mucosa") by renal cell carcinoma is a feature of high-stage tumors. 3,4 Renal pelvicalyceal system involvement by papillary renal cell carcinoma is extremely rare, and most of the data are derived from studies involving clear cell renal cell carcinoma. 3,4 In a study involving the Mayo Clinic nephrectomy registry (8225 patients; 1970 to 2017), only 5 cases originally classified as papillary renal cell carcinoma were documented to involve the pelvicalyceal system.…”

Challenges in Paragangliomas and Pheochromocytomas: from Histology to Molecular Immunohistochemistry

“…Keratin expression is almost always absent, except for rare subtypes such as duodenal gangliocytic paragangliomas and cauda equina paragangliomas [ 14 ]. When assessing these lesions, the pathologist needs to consider many different aspects, including clinical information, primary tumor site, histology, the extent of invasion, the presence of vascular invasion, as well as the novel TNM staging system as dictated by the 8th edition of the American Joint Committee on Cancer (AJCC) Staging Manual [ 19 , 20 ]. Interestingly, even though the TNM system for PPGL is newly adopted, the staging seems to reflect the biological properties and clinical outcomes when applied on retrospective materials [ 21 ].…”

“…Interestingly, even though the TNM system for PPGL is newly adopted, the staging seems to reflect the biological properties and clinical outcomes when applied on retrospective materials [ 21 ]. In addition, the pathologist could also consider to implement histological scoring algorithms in order to stratify the future risk of metastatic disease [ 19 ]. Although all PPGLs are considered to exhibit malignant potential, only 10–15% of pheocromocytomas and between 30 and 50% of abdominal paragangliomas will metastasize to non-chromaffin sites [ 7 ].…”