CITOLOGIA PER AGO SOTTILE (FNC) DELLE MASSE RENALI

Cytology of normal structures of the kidney:Glomeruli structures(lobulated structures, small crowded nuclei) Proximal convoluted tubule cells(fairly large cell with large, granular well-defined cytoplasm, eccentric, round nuclei with dense chromatin; dd with r. oncocytoma)Distal convoluted tubule cells (sincytial, smaller nuclei cells with scanty, ill-defined, non-granular cytoplasm). non-tumoral processes:Pyelonefritis, Xantogranulomatous pyelonefritis, Malacoplakia, Renal infarct, cystic lesions. Benign renal neoplasms:Angiomyolipoma, Metanephric adenoma, Renal oncocytoma, Renal cortical adenoma. Angiomyolipoma (AML): Origin from perivascular epithelioid cells, Sporadic/tuberose sclerosis (50%), Male/female 2/1, Single or multiple, Benign (may extend in the vena cava or spread to regional lymph nodes, exceptional sarcomatous transformation), Imaging non diagnostic Cytological findings: smooth muscle cells, adipocytes, foamy macrophages, giant histiocytes, inflammatory cells, HMB45+. Renal oncocytoma:3% all renal tumors with higher median age (65yrs oncocytoma vs 55 yrs RCC), thin capsule, brown because of lipochrome in the mitochondria, central scar, Cytological findings: large, eosinophilic cells, one or two small, nucleolated nuclei, possible macronucleoli and atypia. Metanephric adenoma:Children or young adults, Pathology: well circumscribed, cellular, uniform, small cells, acinar pattern, Cytological findings: small, lymphocyte-like, monomorphic, hyperchromatic cells with scanty cytoplasm and small nucleoli. Acinar or tubular pattern (dd: Wilms’ tumour). Renal cell carcinoma (RCC):3% of adults malignancies, Male/female 1.6 / 1, peak incidence 6° decade, Risk factor: tobacco, cystic kidney, von Hippel-Lindau (40-55%), Chromosomal abnormalities: 3 in clear cell, 17 and 7 papillary type, Asymptomatic, haematuria, flank pain, Diagnosis: CT, US, fine-core needle biopsy. Classification and grading:Clear cell (hypernephroid), Chromophil (papillary), Chromophobe, Collecting duct type. Fuhrman grading system:I Nuclei round, uniform, +/- 10μm, nucleoli small or absent, II Nuclei slightly irregular, +/- 15μm, nucleoli evident, III Nuclei very irregular, +/- 20μm, nucleoli large and prominent IV Nuclei pleomorphic, multilobated, 20μm or more, chromatin clumped and prominent nucleoli.RCC cytological features:Cluster or isolated cells with abundant clear cytoplasm, Low nuclear / cytoplasmic ratio, Nuclei and nucleoli size depending on the grade of differentiation, Occasional very large nuclei, Cytoplasmic eosinophilic globules, oil red-O +. RCC papillary type (chromophil type) cytological features:RCC papillary type I and type II Papillary cluster with fibrovascular cores, Small nuclei with grooves, Histiocytes and psammoma bodies may be present Cytoplasmic hemosiderin, DD: urothelial cell, clear cell carcinoma, oncocytoma. RCC chromophobe type:Lower median age, Male/female 1/1, Better prognosis, cytological features, Cells isolated or in small groups, Flocculent or granular cytoplasm Thickned cell borders, perinuclear halos (koilocytic), Binucleated cells, Intranuclear inclusion, Colloidal iron+.