Cutaneous Keratocyst David Cassarino, MD, PhD Key Facts Terminology NBCCS cutaneous cyst/Gorlin-Goltz syndrome Rare cutaneous cyst showing features identical to oral keratocysts Etiology/Pathogenesis Most cases are associated with NBCCS Rare…
Steatocystoma (Multiplex) Steven D. Billings, MD Key Facts Terminology Benign cyst derived from the sebaceous duct that may present as multiple lesions (steatocystoma multiplex) or as a single lesion (simplex)…
Vellus Hair Cyst Senait W. Dyson, MD Key Facts Terminology Similar histology to epidermoid cyst with the addition of intraluminal vellus hairs Clinical Issues Small, discrete, follicular papules; often on…
HPV-related Epidermal Cyst Elsa F. Velazquez, MD David Cassarino, MD, PhD Key Facts Etiology/Pathogenesis HPV-related cysts Verrucous cysts have been reported to be associated with HPV-20 and -34 Epidermoid cyst…
Proliferating Pilar (Tricholemmal) Cyst/Tumor David Cassarino, MD, PhD Key Facts Terminology Proliferating pilar tumor (PPT), proliferating pilar cyst (PPC), proliferating trichilemmal cyst/tumor Multicystic squamous neoplasm composed of mature keratinocytes lining…
Pilar (Tricholemmal) Cyst Steven D. Billings, MD Key Facts Clinical Issues 90% of pilar cysts present on scalp Microscopic Pathology Circumscribed simple cyst Filled with dense eosinophilic keratin Stratified squamous…
Epidermoid/Epidermal Inclusion Cyst Elsa F. Velazquez, MD Key Facts Etiology/Pathogenesis Infundibular cyst variant Implantation (inclusion) cyst variant Clinical Issues Very common lesions Usually affecting face, neck, and trunk Microscopic Pathology…
Mast Cell Disease Carlos E. Bueso-Ramos, MD, PhD Roberto N. Miranda, MD L. Jeffrey Medeiros, MD Key Facts Clinical Issues Multiple clinical variants; common variants are Cutaneous mastocytosis Indolent systemic…
Follicular Lymphoma Roberto N. Miranda, MD Key Facts Terminology Follicular lymphoma (FL) Etiology/Pathogenesis Bcl-2 overexpression is present in most cases of FL Results from t(14;18)(q32;q21)/IgH–BCL2 Other factors are involved in…
Histiocytic Sarcoma Roberto N. Miranda, MD Key Facts Terminology Malignant neoplasm composed of mature histiocytes Diagnosis based mainly on morphology and immunophenotype Etiology/Pathogenesis Transdifferentiation in subset of cases B-cell lymphoma…
