Indeterminate cell histiocytosis

Indeterminate cell histiocytosis (LCH) is an uncommon proliferative illness where the predominant cells have characteristics from both non-Langerhans cell histiocytosis (NLCH) and Langerhans cell histiocytosis (LCH) in terms of morphology and immunophenotypic characteristics.^[1] Wood et al. originally described ICH in 1985 as a neoplastic disease arising from dermal indeterminate cells that lack Birbeck granules but are characteristically positive for S-100 and CD1a.^[2]

Indeterminate cell histiocytosis
Other names	Indeterminate dendritic cell tumor
Specialty	Dermatology

Signs and symptoms

Clinically, ICH is defined by pink to reddish, varying-sized, painless, non-itching papules or nodules that develop on otherwise healthy skin (sparing mucosae). These lesions can appear as a single, distinct group of lesions, or several generalized papules dispersed over the trunk, face, and limbs. They can also show signs of stable disease, remission and recurrence, or spontaneous remission.^[3]

Causes

Possible causes include scabies,^[4] mosquito bites,^[5] and a clonal drive.^[6]

Treatment

Treatment include 5% 5-fluorouracil cream, topical pure coal tar, electron beam therapy, phototherapy, and total excision.^[7][8]

See also

• Non-X histiocytosis
• List of cutaneous conditions