Basicmedical Key

 Solitary circumscribed neuroma (“palisaded encapsulated neuroma”) represents spontaneous proliferation of peripheral nerve fibers  Multiple mucosal neuromas associated with multiple endocrine neoplasia syndrome (type 2B) represents rare autosomal dominant condition  Traumatic…

 Inflammatory component shows variable mixtures of lymphoplasmacytic cells, eosinophils, neutrophils, and histiocytes • Areas with prominent myxoid change • Scattered enlarged atypical tumor cells, some with macronucleoli  Cells with macronucleoli resemble Reed-Sternberg…

 Elongated and anastomosing rete ridges  Atypical basal cells with hyperchromatic-staining nuclei  Subtle abnormal maturation (large, eosinophilic keratinocytes)  Whorling and keratin pearl formation  Usually associated with LS&A  Preferential association with HPV-unrelated…

 Skin metastases: Nodule, often pigmented, may be ulcerated, multiple or solitary  Nodal metastases: Usually in regional lymph nodes  Blue nevus-like melanoma: Blue macule/papule, often near original site of primary melanoma…

 Most patients have good prognosis, with only minority of cases progressing to systemic disease or death Microscopic • Severely atypical/borderline Spitz tumor  Typically, large and deep cellular compound melanocytic tumors  May…

 Genes implicated include PTCH1 (Gorlin syndrome),  TP53, SOX9, BMI1, BAX, RMRP Clinical Issues • Extremely common: Most common cancer in humans • Most common in head and neck region (up to…

 Usually presents on scalp in infancy, often at birth  Presents as yellowish flat to warty plaque; enlarges during puberty • Basaloid follicular hamartoma  Usually presents in adults Microscopic • Nevus sebaceus  Abnormalities…

 Represent < 0.5% of all oral malignancies • Mean in 6th-7th decades • M > F (2.5-3:1) • Hard palate and maxillary alveolus are most common sites of involvement (~ 80%) • Cervical lymph…

 Benign clear cell adnexal proliferation with external root sheath differentiation • Subtype: Desmoplastic tricholemmoma Etiology/Pathogenesis • Some cases are associated with Cowden syndrome (PTEN hamartoma syndrome)  Multiple tricholemmomas, hamartomas, and visceral tumors…

 Solitary form (myofibroma)  Multicentric form (myofibromatosis) • Synonyms: Infantile myofibromatosis, congenital generalized fibromatosis  Continuum with lesions termed myopericytoma and infantile hemangiopericytoma Clinical Issues • Most common from birth to 2 years • Most…