Nephrogenic rests are abnormally per sistent foci of embryonal cells (still pre sent after 36 weeks of gestation) that are potentially capable of developing into nephroblastoma (also called Wilms tumour). The presence of diffuse or multifocal nephrogenic rests is called nephroblastomatosis.
Nephrogenic rests are found in 25-40% of patients with nephroblastoma, and in approximately 1% of term infant autopsies.
Nephrogenic rests can be found adjacent to nephroblastoma or in the surrounding renal parenchyma. They are classified into perilobar and intralobar types.
Here are 5 differences between perilobar and intralobar nephrogenic rests.
Perilobar nephrogenic rests are peripherally located, wheras intralobar nephrogenic rests are randomly intermingled between the renal parenchyma, typically located in the central areas of the lobe.
2. DEMARCATION FROM ADJACENT PARENCHYMA
Perilobar nephrogenic rests are sharply demarcated from the surrounding tissue, whereas intralobar nephrogenic rests are poorly demarcated, usually infiltrate among native nephrons.
Perilobar nephrogenic rests have scanty stroma, whereas intralobar nephrogenic rests are and are composed mainly of stromal and epithelial elements.
Perilobar nephrogenic rests are usually multifocal whereas, intralobar nephrogenic rests are mostly unifocal (often single).
5. ASSOCIATED CONDITIONS
Perilobar nephrogenic rests are associated with hemihypertrophy and overgrowth syndromes such as Beckwith-Wiedemann syndrome. lntralobar nephrogenic rests are associated with Denys-Drash syndrome (which is associated with nephroblastoma, pseudohermaphrodit ism, glomerulopathy, and renal failure) and WAGR syndrome (Wilms tumour / nephroblastoma, aniridia, genitourinary anomalies, and mental retardation syndrome).
PERILOBAR AND INTRALOBAR NEPHROGENIC RESTSHISTOPATHOLOGICPICTURES.
Molecular progression of serous ovarian tumor. Borderline low and high grade
1.Molecular progression of low grade ovarian serous tumors. There is data to suggest progression from serous cystadenoma / cystadenofibroma with BRAF / KRAS mutations → SBT (serous borderline tumor) → LGSC (Low grade serous carcinoma) ; however, this is still controversial
2. Molecular progression of high grade serous ovarian tumors.
TP53 alterations in nearly all cases of high grade serous carcinoma
Germline, somatic or promoter hypermethylation (inactivation) of BRCA1 and BRCA2 in ~50% of cases
Gastrointestinal pathogens are very common in routine practice. It takes experience and keen observation to differentiate gastrointestinal pathogens from one another. In case of confusion, go with your ‘GUT’ feeling.
Lets look at a few differentiating features of Giardia lamblia, Cryptosporidium parvum and Isospora belli.
Pear shaped trophozoites with 2 ovoid nuclei, present in the luminal surface. They are 10-15 microns in length and 5-9 microns in width.
GIARDIA IS SEEN IN THE LUMINAL SURFACE
CRYPTOSPORIDIUM IS SEEN ATTACHED TO ENTEROCYTES LIKE SMALL BEADS.
2. CRYPTOSOPORIDIUM PARVUM
In tissue biopsies, 2 – 5 μm basophilic round bodies are seen protruding from the apex of enterocytes (“blue beads”) within the cell membrane. Parasites bulge out of apex of epithelial cells
ISOSPORA IS LARGEST AMONG THE THREE. IN CONTRAST TO GIARDIA AND CRYPTOSPORIDIUM – ISOSPORA DOES NOT HAVE AN APICAL LOCATION, INSTEAD LOCATED IN THE TIP OF VILLI.
3. ISOSPORA BELLI
Oocysts are generally ovoid to ellipsoid in shape, range from 10-40µm in length by 10-30µm in width. Cysts are present in PARASITO- PHOROUS VACUOLE. Does not have an apical location.