We have posted updated reviews of the following topics:Kidney tumor > Benign adult tumors > Renomedullary interstitial cell tumor
by Rachelle Gietzen, M.D., Eduardo Eyzaguirre, M.D.
Topic summary: Tumor often found incidentally at autopsy or imaging for other reasons. Arises from medullary interstitial cells, seen as gray-white nodules in renal medulla, composed of spindled cells in basophilic stroma with entrapped tubules.
Microbiology & parasitology > Atypical bacteria: Mycoplasma > M. hominis / Ureaplasma spp.
by Arthur H. Totten, Ph.D., George Andy Farr, M.L.S., Sixto M. Leal, Jr., M.D., Ph.D.
Topic summary: M. hominis / Ureaplasma spp. are atypical bacterial pathogens which stain poorly by the dyes used in Gram stain due to the absence of a cell wal. They cause urogenital syndromes and infections in transplant patients and neonates. Culture requires specialized media conditions.
Oral cavity & oropharynx > Congenital anomalies > Hairy tongue
by Molly Housley Smith, D.M.D.
Topic summary: Hairy appearance of the dorsal tongue due to marked elongation of the lingual filiform papillae. Great clinical and micro images.
Salivary glands > Cytopathology (Milan system) > Milan system – Neoplasm: benign
by Jen-Fan Hang, M.D.
Topic summary: This is the second topic in the Salivary gland chapter regarding the Milan System for Reporting Salivary Gland Cytopathology (see also http://www.pathologyoutlines.com/topic/salivaryglandsmilandiagnostic.html), published in 2018. It describes salivary gland FNA diagnostic of a benign neoplasm (pleomorphic adenoma 60 – 70%, Warthin tumor 20 – 30%). The estimated risk of malignancy by the Milan system is < 5%.
Thyroid gland > Papillary carcinoma > Columnar cell variant
by Shipra Agarwal, M.D., Andrey Bychkov, M.D., Ph.D.
Topic summary: The columnar cell variant of papillary thyroid carcinoma is rare and aggressive. It features columnar cells with nuclear pseudostratification, scant cytoplasm and absent / minimal nuclear features of papillary thyroid carcinoma. It should be differentiated from metastatic colon and endometrial adenocarcinoma .