We have posted updated reviews of the following topics:Bladder, ureter & renal pelvis > Squamous cell neoplasms > Squamous cell carcinoma
by Susan Prendeville, M.D.
Topic summary: Uncommon subtype of carcinoma showing pure squamous morphology without any component of conventional urothelial carcinoma. Caused by Schistosoma infection, smoking and chronic irritation. Must be distinguished from urothelial carcinoma with squamous differentiation and secondary spread of squamous cell carcinoma primary to cervix, penis or anus.
Bladder, ureter & renal pelvis > Glandular neoplasms > Villous adenoma
by Varsha Manucha, M.D.
Topic summary: Villous adneoma is a rare bladder tumor and even rarer as an isolated lesion in native bladder. Most are diagnosed with coexistant malignancy and recently was reported coexisting with neuroendocrine carcinoma following augmentation cystoplasty.
Bone > Other tumors > Mazabraud syndrome
by Travis H. Johnson, D.O., M.S., Jessica L. Davis, M.D.
Topic summary: Rare disorder due to postzygotic activating somatic mutations in the GNAS gene. The exact presentation and severity depend on the extent of mosaicism and the involved tissues. Most patients are diagnosed in adulthood. Consists of fibrous dysplasia of bone, either polyostotic or monostotic and one or more intramuscular myxomas.
Chemistry, toxicology & urinalysis > General chemistry > Metabolism > Parathyroid hormone
by Patricia Tsang, M.D., M.B.A.
Topic summary: Maintains serum calcium within a tight range of 9 – 10 mg/dL, mobilizes calcium from bone, increases calcium reabsorption from the kidney and stimulates calcium absorption from the gut. 84 amino acids derived from cleavage of prepro parathyroid hormone (PTH); biologic activity due to 34 amino acids at amino terminus; other portions are inert but may give false positives in detection systems.
Colon nontumor > Noninfectious colitis > Lymphocytic colitis
by Martha M. Yearsley, M.D.
Topic summary: Chronic nonulcerating colitis; subtype of microscopic colitis. Common cause of chronic nonbloody diarrhea in older adults with normal or near normal colonoscopy and increased intraepithelial lymphocytes as the histologic hallmark.
We have added new images to the topics:Oral cavity & oropharynx > Other nonneoplastic > Mucocele
clinical images contributed by Nathan Lee, D.M.D.