What is the definition of Reticulohistiocytoma?

Reticulohistiocytoma (RH) is a rare benign lesion of the soft tissue. It belongs to a group of disorders called non-Langerhans cell histiocytosis and is a type of reticulohistiocytosis, all of which are types of histiocytosis. Histiocytosis is a condition in which there is rapid production (proliferation) of histiocytes (immune cells) in the skin or soft tissues. The stimulus that causes the immune system to react in RH is currently not well understood. RH present as a yellow to reddish-brown smooth surfaced, firm nodule or lesion on the trunk and/or extremities of the body. Historically, RH has been found in young adults, with a slightly higher incidence in males. RH typically resolve spontaneously over a period of months to years, are not associated with systemic disease, and do not otherwise affect health. Treatment involves surgical removal of the lesion.

What are the alternative names for Reticulohistiocytoma?

  • Solitary reticulohistiocytosis
  • Solitary histiocytoma

What are the causes for Reticulohistiocytoma?

While it is known that reticulohistiocytoma (RH) develop due to a rapid production of immune cells (histiocytes) in the skin or soft tissues, the cause of this process is not currently known.

What are the current treatments for Reticulohistiocytoma?

Reticulohistiocytoma (RH) typically resolve spontaneously over a period of months to years; however, surgical excision usually results in a cure.

What is the outlook (prognosis) for Reticulohistiocytoma?

The long-term outlook (prognosis) for Reticulohistiocytoma (RH) is good. RH is thought to represent a benign skin lesion. RH tends to spontaneously resolve over a period of months to years and affected individuals remain healthy. Recurrence of RH is rare.

How is Reticulohistiocytoma diagnosed?

The diagnosis of reticulohistiocytoma (RH) is made based on clinical presentation, histology, and immunohistochemistry profile. RH occur in isolation and are typically described as small, yellow to reddish-born nodules. The lesions usually are slightly elevated from the surrounding skin. Detailed information on histology of reticulohistiocytoma is available through DermNet NZ, an online resource about skin diseases developed by the New Zealand Dermatological Society Incorporated. There are several differential diagnoses for RH. It is important to distinguish RH from Rosai-Dorfman disease, juvenile xanthogranuloma, a variety of granulomatous conditions, and some malignant neoplasms, including histiocytic sarcoma, melanoma, and epithelioid sarcoma. Reticulohistiocytoma should also be distinguished from multicentric reticulohistiocytosis.
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  • Journal: Journal of medical case reports
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  • Number of Patients: 1
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This case report describes a 33-year-old Egyptian female diagnosed with macrophage activation syndrome triggered by systemic lupus erythematosus flare treated with a combination of dexamethasone sodium phosphate, intravenous immunoglobulin, and cyclosporine.
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  • Treatment Used: PD-1 Antibody Plus Lenvatinib
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Clinical Trial
  • Status: Recruiting
  • Phase: Phase 2
  • Intervention Type: Drug, Biological, Procedure, Radiation
  • Participants: 25
  • Start Date: October 13, 2017
Cord Blood Ex-Vivo MSC Expansion Plus Fucosylation to Enhance Homing and Engraftment