We have posted updates of the following topics:
Colon > Infectious colitis > Intestinal spirochetosisby Giby V. George, M.B.B.S., Aaron R. Huber, D.O.
Topic summary: Colonization of the colonic epithelium by the filamentous nontreponemal anaerobic spirochetes, Brachyspira aalborgi or Brachyspira pilosicoli. Most commonly asymptomatic but may present with diarrhea or abdominal pain / cramps. Human intestinal spirochetosis (HIS) has a global distribution and Brachyspira species have been detected on nearly every continent, with the exception of Antarctica. Pathogenesis, transmission and risk factors remain unclear. Gold standard for diagnosis is histologic examination of an endoscopic colon or rectal biopsy. Metronidazole is the most commonly utilized antibiotic for symptomatic patients; symptoms will resolve in the majority of patients (81%).
Gallbladder & extrahepatic bile ducts > Gallbladder nonneoplastic > Cholesterolosis
by Reem Hamasha, M.D., Raul S. Gonzalez, M.D.
Topic summary: Accumulation of lipids (triglycerides, cholesterol precursors and cholesterol esters) within subepithelial macrophages in the lamina propria of the gallbladder. Focal, diffuse or polypoid (polypoid cholesterolosis = cholesterol polyps). Also known as strawberry gallbladder. Seen in 10 – 30% of cholecystectomies; occurs in female patients 75% of the time and associated with high BMI. Asymptomatic, noninflammatory; no malignant potential. Incidentally found during abdominal sonography (appears as a pseudopolyp) or diagnosed on histopathology of surgical specimens; microscopic examination provides the definitive diagnosis. Treatment: cholecystectomy.
Skin nonmelanocytic tumor > Adnexal tumors > Sebaceous glands > Nevus sebaceus of Jadassohn
by Ronan Knittel, M.D., Nima Mesbah Ardakani, M.D.
Topic summary: Nevus sebaceus of Jadassohn (sebaceous nevus, organoid nevus) is a hamartoma that is histologically characterized by a complex and abnormal proliferation of epidermis and adnexal structures. Commonly presents at birth as a single yellow patch of alopecia on the scalp, becomes verrucous during childhood and puberty and shows variable enlargement during adulthood (due to development of a range of often benign and seldom malignant tumors). Nevus sebaceus is now considered as a mosaic RASopathy with postzygotic somatic mutations of the Ras protein family, mainly due to HRAS and rarely KRAS mutations, in a section of the skin. Generally, nevus sebaceus will follow a benign course. Generally safe to observe; surgical excision as a cosmetic procedure or to remove a secondary neoplasm.
Transfusion medicine > Therapeutic apheresis > ASFA guidelines overview
by Muharrem Yunce, M.D., Mrigender Singh Virk, M.D.
Topic summary: Apheresis is a modality in which the blood of a person is passed through a device that separates blood into different components, removes 1 constituent and returns the rest, with or without a replacement fluid. American Society for Apheresis (ASFA) publishes guidelines to systematically review the available evidence and provides a categorical way to approach the request of apheresis procedures in different diseases. ASFA guidelines organize diseases and their therapies into category and grading systems; category describes the efficacy and priority of apheresis in treatment of a disease while grading describes the quality of evidence to support apheresis treatment of a disease.