Pathology Notes

Rosacea Updated: 12/21/2023 © Jun Wang, MD, PhD   General features AKA acne rosacea May involve skin or eye More common in light skin populations, adult Five subtypes Erythematotelangiectatic Granulomatous Papulopustular Phymatous Ocular Usually clinical diagnosis Pathogenesis Unclear etiology, likely multi-factorial Immune dysfunction Ultraviolet radiation Physical or chemical trauma  Microorganisms: Demodex mites ( D. folliculorum and D. brevis ), bacillus oleronius Vascular hyper-reactivity Probably genetic background: family history Clinical features May involve skin and eyes Skin manifestions Central facial erythema Papules, pustules , flushing, telangiectasia Phymatous changes (rhinophyma) Ocular manifestions Lid margin telangiectases Interpalpebral conjunctive injection Spade-shaped corneal infiltrate Pathological findings Perifollicular lymphocytic infiltration and vascular ectasia Management Avoid triggering factors Laser, surgery, etc Back to acute i

Nevoid basal cell carcinoma syndrome Updated: 05/19/2020 © Jun Wang, MD, PhD General features AKA Gorlin syndrome, basal cell nevus syndrome, etc Autosomal dominant  Germline mutation of PTCH1 Multiple developmental abnormalities Increased risk for childhood medulloblastoma Pathogenesis Inactivation of PTCH1, receptor for hedgehog protein Loss of suppression of Smoothened (SMO) Probably downstream over activation of transcription factors Gli1 and/or Gli2 Clinical presentations Major manifestations Early development of basal cell carcinoma Odontogenic keratocyst Palmar and plantar pits Lamellar calcification of the falx cerebri Family history of nevoid basal cell carcinoma syndrome   Minor manifestations Childhood medulloblastomas Craniofacial anomalies: Cleft lip/palate, macrocephaly, frontal bossing , hypertelorism Vertebral/rib anomalies, such as bifid/splayed/extra ribs or bifid vertebrae Polydactyly Cardiac or ovarian fibromas , often b

Practice question answers, skin tumors 3 © Jun Wang, MD, PhD 1. E. The lesion is characterized by partial or complete loss of melanin pigmentation without other abnormalities, most consistent with vitiligo . Actinic keratosis is a squamous precancerous lesion with rough surface or cutaneous horn . Dermatophytosis is fungal infection and is usually an erythematous, centrifugally growing annular lesion with a peripheral scale . Scar may have hypopigmentation but usually has a bulging appearance due to regenerative changes. 2. C. Vitiligo is associated with autoimmune destruction of melanocytes. Allergic reaction is associated with various dermatitis, including allergic contact dermatitis , urticaria , and erythema multiforme , etc. Excess estrogen associated hyperpigmentation is seen in melasma . Sun exposure is associated with hyperpigmentation, such as melasma , and proliferative disorders lentigo , melanoma , squamous cell carcinoma and   basal cell carcinoma . Tyrosina