Cutaneous Plasmacytoma Aaron Auerbach, MD, PhD David Cassarino, MD, PhD Key Facts Terminology Neoplasm of monoclonal plasma cells Must 1st rule out plasmacytoid B-cell lymphoma Clinical Issues Skin is rare…

Polyvinylpyrrolidone Storage Disease Cyril Fisher, MD, DSc, FRCPath Key Facts Etiology/Pathogenesis Phagocytic foreign body-type reactive condition Found in aerosol hair sprays, adhesives, lithographic solutions, shaving products, plastics Used to improve…

Rosai-Dorfman Disease Elizabeth A. Montgomery, MD Key Facts Terminology Lesional histiocytes contain variable numbers of intact lymphocytes within their cytoplasm Referred to as lymphophagocytosis or emperipolesis Sinus histiocytosis with massive…

Multicentric Reticulohistiocytosis David Cassarino, MD, PhD Key Facts Terminology Giant cell reticulohistiocytosis Clinical Issues Most cases occur in adults > 40 years old Multiple nodules and arthropathy Prognosis is variable;…

Reticulohistiocytoma David Cassarino, MD, PhD Key Facts Terminology Proliferation of histiocytes with abundant dense, glassy-appearing eosinophilic cytoplasm Clinical Issues Usually occurs in adults > 40 years old, but cases have…

Juvenile and Adult-type Xanthogranuloma Elizabeth A. Montgomery, MD Key Facts Terminology Stable or regressing histiocytic lesion that usually occurs in childhood Form of non-Langerhans histiocytosis Clinical Issues Majority in individuals…

Osteoma Cutis David Cassarino, MD, PhD Key Facts Etiology/Pathogenesis Primary: May be part of Albright hereditary osteodystrophy or other genetic syndromes Secondary: Associated with preexisting lesions, such as nevi, tumors,…

Chondroma David R. Lucas, MD Key Facts Terminology Benign hyaline cartilage neoplasm of soft tissue with predilection for hands and feet Synonyms: Extraskeletal chondroma, chondroma of soft parts, osteochondroma, myxochondroma…

Atypical Lipomatous Tumor and Liposarcoma Elizabeth A. Montgomery, MD Key Facts Terminology Intermediate (locally aggressive, nonmetastasizing) lipogenic neoplasm composed of atypical adipocytes Clinical Issues Accounts for 40-45% of all liposarcomas…

Hibernoma Khin Thway, BSc, MBBS, FRCPath Key Facts Terminology Benign tumor with differentiation toward brown fat, most frequently seen in younger adults Clinical Issues Peak incidence in 3rd decade Most…