Indeterminate cell histiocytosis successfully treated with narrowband UVB

Abstract

We present a 47-year-old man with a sudden eruption of more than 100 reddish-brown papules, which histologically exhibited a dense dermal proliferation of large mononuclear cells with vesicular nuclei and abundant pale cytoplasm. Electron microscopy and immunohistochemistry revealed findings consistent with indeterminate cell histiocytosis and the patient responded well to treatment with narrowband UVB therapy. Case synopsis:A 47-year-old, otherwise healthy man with a history of mild plaque psoriasis presented to his dermatologist for evaluation of two asymptomatic, reddish brown, dome shaped papules on his abdomen. The lesions had been present and asymptomatic for several weeks and further evaluation and treatment was initially deferred given the banal appearance of the lesions. In ensuing weeks however, the number of similar appearing lesions increased and spread centrifugally from his trunk to his extremities and face. When the patient returned for a follow up several weeks later, he had over a hundred lesions involving his entire body, but most prominent on this trunk (Figures 1 and 2). Punch biopsies of representative lesions were obtained at this time. A systemic workup was also performed as even though the patient remained in good health, the sudden increase in the number of skin lesions raised concern for internal disease. A systemic workup including bone marrow biopsy, computed tomography scan of the chest, abdomen and pelvis, complete blood count, and complete metabolic panel was performed. The results of these evaluations were normal except for a mild thrombocytopenia. Given the negative systemic work up and the patient's continued overall good health, concern for systemic involvement was considered minimal.

Indeterminate cell histiocytosis: A systematic review of the literature with a comprehensive revision of clinical, histopathological, and molecular features

“…From the first literature search and after deduplication and screening for ICH reports, we gathered 96 papers, describing 142 patients, and spanning from 1985 to 2022. Subsequently, applying the inclusion criteria for the diagnosis of ICH, we excluded 18 papers 14–31 . We then selected and included in the study 78 papers, describing 108 patients (Figure 1).…”

“…Subsequently, applying the inclusion criteria for the diagnosis of ICH, we excluded 18 papers. [14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31] We then selected and included in the study 78 papers, describing 108 patients (Figure 1). 5,8,9,12, From two case series, we included only some of the described patients, as indicated in Table 1.…”

A Case of Indeterminate Cutaneous Dendritic Cell Tumors in the Setting of Chronic Myelomonocytic Leukemia

“…With regards to cutaneous IDCN associated with CMML, UV therapy ± psoralen appears to be quite promising given the excellent recorded responses and improved tolerability of treatment. 4,6,16–18 Chemotherapy and total skin electron beam therapy have been reported effective in multilesional cases, although relapses requiring additional treatments appear common. 3,14,15…”

“…With regards to cutaneous IDCN associated with CMML, UV therapy 6 psoralen appears to be quite promising given the excellent recorded responses and improved tolerability of treatment. 4,6,[16][17][18] Chemotherapy and total skin electron beam therapy have been reported effective in multilesional cases, although relapses requiring additional treatments appear common. 3,14,15 In summary, the literature describes IDCN as a cutaneous proliferation of histiocyte-like cells, which are typically positive for CD1a and S100, negative for langerin, and strongly associated with concomitant hematopoietic neoplasm.…”