We have posted updates of the following topics:Anus & perianal area > Other nonneoplastic > Fistula
by Fahire Goknur Akarca, M.D., Nikka Khorsandi, M.D., Kwun Wah Wen, M.D., Ph.D.
Topic summary: Anal fistulas are epithelialized tracts created between an external opening in the perianal skin and an internal opening in the anal canal. Benign epithelialized communication between anal canal and perianal skin that is most commonly idiopathic. Mean age of occurrence is 40 years with a range of 20 – 60 years. Most commonly identified causes of anal fistulas are Crohn’s disease, infections and rectal foreign bodies. Treatment: exam under anesthesia is the most common first step of a suspected fistula, to determine complexity and characteristics. Simple fistula is treated with a primary fistulotomy with incision made along fistula tract for curettage and to promote adequate tract drainage and wound healing; this is very curative.
CNS & pituitary tumors > Gliomas, glioneuronal tumors, and neuronal tumors Adult-type diffuse gliomas > Astrocytoma, IDH mutant
by John DeWitt, M.D., Ph.D.
Topic summary: IDH1 / IDH2 mutated, diffusely infiltrating glioma, most often with concurrent TP53 or ATRX mutations and without 1p / 19q codeletion. In the absence of 1p / 19q codeletion, a component that morphologically resembles oligodendroglioma is compatible with this diagnosis. Age of diagnosis is typically younger than glioblastoma, IDH wild type, with higher grade tumors occurring more often in older patients (third or fourth decade for grade 2 or 3, versus fifth decade for grade 4). Within IDH mutant astrocytoma, younger age is correlated with improved prognosis and survival. Complete resection as extensively as is safely possible.
Oral cavity & oropharynx > Soft tissue tumors & proliferations > Parulis
by Molly Housley Smith, D.M.D.
Topic summary: Localized collection of acute inflammation and edematous granulation tissue on the gingiva, which represents the intraoral opening of a draining odontogenic (dental) infection. Diagnosis is most often made upon clinical evaluation of fluctuant / draining gingival nodule associated with adjacent dental infection; histopathologic confirmation is useful but may not be needed. Parulides may be accompanied by an ill or well defined radiolucency at or around the apex of a nonvital tooth. While the gingival nodule may be removed surgically, the nodule will recur without effective treatment of the underlying associated infection (e.g., root canal therapy, dental extraction, etc.).
Stomach > Neuroendocrine tumors > Well differentiated neuroendocrine tumor
by Dana Razzano, M.D., Teri A. Longacre, M.D.
Topic summary: The 5th edition of the WHO 2019 Digestive Tumors Classification definition of neuroendocrine tumor (NET): well differentiated, grade 1, 2 or 3 based on mitotic rate per 2 mm2 (based on counting 10 mm2 and taking the average) and Ki67 immunohistochemical index (counted in ≥ 500 cells in the area of highest staining); grade assigned by whichever value is higher. Type I is the most common, followed by type III, with type II being very rare. All types tend to occur in the age range of 50 – 60 years. Prognostic factors: dependent on tumor subtype, grade and stage at presentation. Treatment: dependent on size at time of endoscopic evaluation.