Reticulohistiocytoma



Reticulohistiocytoma


David S. Cassarino, MD, PhD









Low-power examination shows a dense nodular to sheetlike collection of large histiocytic cells in the dermis.






High-power view shows large histiocytic cells with abundant dense, glassy-appearing cytoplasm image and a background inflammatory infiltrate containing neutrophils and eosinophils.


TERMINOLOGY


Synonyms



  • Solitary cutaneous reticulohistiocytoma (SCR)


  • Reticulohistiocytic granuloma


  • Giant cell reticulohistiocytoma


Definitions



  • Proliferation of histiocytes with abundant dense, glassy-appearing, eosinophilic cytoplasm


ETIOLOGY/PATHOGENESIS


Environmental Exposure



  • May be related to stimuli, such as insect bites, infection, trauma, or ruptured folliculitis or cyst


CLINICAL ISSUES


Epidemiology



  • Incidence



    • Rare tumor


  • Age



    • Usually occurs in adults > 40 years old



      • However, some cases have been reported in adolescents


  • Gender



    • Equal male and female incidence


  • Ethnicity



    • Most cases occur in Caucasians


Site



  • Usually head and neck region, including mucosal sites



    • However, may present at any cutaneous site


Presentation



  • Skin papule or nodule



    • Usually single lesion, but several may be present in some cases


  • Firm, rapidly growing lesion


  • Usually appear as red-brown or yellow-brown


  • May be preceded by trauma in some cases


  • Lack of systemic symptoms, including fever, weight loss, or weakness (which may be seen in multicentric reticulohistiocytosis)


Treatment



  • Surgical approaches



    • Complete conservative excision is curative



      • Usually not required unless lesion is very large or fails to resolve


Prognosis



  • Excellent; lesions often involute spontaneously


  • No definite relationship with more aggressive multicentric reticulohistiocytosis



    • However, multiple skin lesions should suggest possibility of generalized cutaneous reticulohistiocytosis


MACROSCOPIC FEATURES


General Features



  • Dermal-based, nodular, well-circumscribed but unencapsulated lesion


Size



  • Lesions typically range in size from 0.5-2 cm


MICROSCOPIC PATHOLOGY


Histologic Features

Jul 9, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Reticulohistiocytoma

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