We have posted updates of the following topics:
Informatics, digital & computational pathology > Artificial intelligence > Machine learning fundamentalsby Jerome Cheng, M.D.
Topic summary: Machine learning is the science of using computer algorithms to learn from patterns present in data and making predictions based on the learned patterns. Some steps in building a machine learning model: data collection and preparation; choosing a programming language / machine learning platform and machine learning algorithm; setting the hyperparameters for the model and splitting the data into training, validation and holdout sets; training and testing the model; optimizing the model. Applications in pathology / laboratory medicine include molecular subtyping of cancer, image recognition / segmentation and identification of lesions in digital slides, digital slide stain normalization, information extraction from pathology reports.
Kidney tumor > Benign / borderline adult tumors > Papillary adenoma
by Vincent Francis Castillo, M.D., Rola Saleeb, M.D., Ph.D.
Topic summary: Benign unencapsulated renal epithelial neoplasm characterized by papillary, tubular or tubulopapillary architecture with low grade nuclei and a diameter of ≤ 15 mm. Prevalent in damaged and injured kidneys; could be related to a progenitor / stem cell-like renal tubular cell population that increases upon kidney damage. More common in those with end stage renal disease, acquired cystic disease, glomerulosclerosis, prolonged hemodialysis and a history of smoking. Asymptomatic; incidentally found in nephrectomies removed for larger tumors or other causes. Thought to be precursors of PRCC; however, the incidence of PRCC is much lower than papillary adenoma, indicating that not all cases have the potential to progress to PRCC.
Penis & scrotum > Dysplasia / carcinoma in situ > Extramammary Paget disease
by Roberto Gonzalez, B.S., Debra L. Zynger, M.D.
Topic summary: Paget disease of the penis and scrotum is a rare, intraepidermal adenocarcinoma; it arises as a primary tumor or from secondary involvement of a nonpenoscrotal neoplasm. Occurs in older men with median age 65 – 72 years; presents as lesions with pruritus, erythema, pain, rash, erosion and exudation. Diagnosis: clinical history and evaluation with a punch biopsy. Unfavorable prognostic factors include younger age, shorter symptom duration, delay in diagnosis, exudation, elevated serum CEA, adnexal involvement, HER2 / neu and p53 expression. Treatment: wide local excision or Mohs micrographic surgery; if surgery is not possible, alternative therapies include imiquimod cream, photodynamic therapy, radiotherapy and chemotherapy.
Penis & scrotum > Infectious > Condyloma acuminatum
by Asra Feroze, M.B.B.S., Ritu Bhalla, M.D.
Topic summary: Human papillomavirus (HPV) associated, nonneoplastic tumor-like growths; typically considered benign. Most frequently occurs in men between 25 and 29 years of age. Transmission by oral, genital and anal sex, through skin contact. Soft and friable papillomatous growth; may occur singly or in moruloid clusters. Detection is through thorough clinical history, physical examination and biopsy. Benign course with high recurrence rate; posttreatment recurrence is seen in 38 – 73% patients with usual benign lesions. Commonly used treatment modalities: podophyllotoxin 0.5% solution or gel; trichloroacetic acid 35 – 85%; cryotherapy with liquid nitrogen; electrofulguration; CO2 laser therapy; Imiquimod cream (5%).
Vulva & vagina > Melanocytic lesions > Dysplastic melanocytic nevus
by Anna Sarah Erem, M.D., Gulisa Turashvili, M.D., Ph.D.
Topic summary: Acquired nevus in the genital area with architectural and cytologic atypia. Morphologically characterized by a significant lentiginous component, well developed shoulder, randomly distributed melanocytic atypia and marked inflammatory infiltrate. Most often diagnosed in reproductive age women. Commonly presents as macules or papules with irregular borders, pink in the center and tan to brown at the periphery. Dysplastic melanocytic nevi are usually associated with activating mutations in genes such as BRAF (typically BRAF V600E) and NRAS. Thought to have a benign clinical course; grade 2 cytologic atypia (former severe dysplasia) may be a precursor to melanoma. Treatment: simple excision is usually sufficient.
Featured Image
Contributed by: Rola Saleeb, M.D., Ph.D. and Vincent Francis Castillo, M.D.
Diagnosis: Papillary adenoma
This tumor blends into adjacent renal parenchyma and lacks a fibrous capsule. It is commonly seen in the background of chronic kidney disease.
Blog | PathologyOutlines.com 