Generalized eruptive histiocytoma: a report of a variant case showing the presence of dermal indeterminate cells

Abstract

We describe a 14-year-old Japanese girl with a variant of generalized eruptive histiocytoma. She presented with the characteristic features of classical generalized eruptive histiocytoma but with the following minor differences. Clinically, some of the papular eruptions tended to coalesce to form plaques. Histoligically, some of the histiocytic cells were S-100 protein- and OKT-6-positive; these were thought to be indeterminate cells because they lacked Birbeck granules. In addition, PAS-positive cells were few and there were some intermingled lymphocytes and a few eosinophils.

Unusual variants of non-Langerhans cell histiocytoses

“…Two clinical subtypes seem to predominate: a solitary nodular form [11][12][13][14]16 (Fig 1, A) and a multiple papulonodular form 3,5,6,[8][9][10]15,[17][18][19][20][21][22][23][24][25][26] (Fig 1, B). The former is usually characterized by a single, soft red asymptomatic nodule about 1 cm in diameter; the latter presents with a widespread eruption of multiple, firm asymptomatic lesions ranging in size from a few millimeters to 1 cm, varying in color from dark red to brownish and covered by intact skin.…”

“…7 Age of onset and incidence ICH affects predominantly adults, showing no sex-or age-specific predilection, although about one third of the cases so far reported in the literature are pediatric. 4,[8][9][10][11][12][13][14][15] Since the original description of Wood et al, 5 only about 20 cases of ICH had been reported, until a recent study on a large collection that included 18 patients with ICH. 4 …”

Diffuse xanthogranulomatous dermatitis and systemic Langerhans cell histiocytosis: A novel case that demonstrates bridging between non-Langerhans cell histiocytosis and Langerhans cell histiocytosis

“…1 It has been recently proposed that similar to the unification of LCH, non-LCH fall along a continuum rather than represent discrete entities. 1,2,5,6,9,11,12,14,16,19 Moreover, the segregation of LCH from non-LCH is called into question when case reports appear that exhibit overlapping features of both conditions. 8,10,13,15,26 Depending on the timing of the biopsy, LCH can cytomorphologically resemble non-LCH and vice versa.…”

“…The aforesaid conditions not only differ in their clinical presentation, they also exhibit slightly different histologic findings (Table I), [2][3][4][5][6]11,13,[16][17][18][19][20][21][22][23][24] and immunohistochemical staining patterns (Table II). [3][4][5][6][7]11,14,[16][17][18]22,25 On the other hand, despite vast clinical differences, all nonpulmonary LCH are composed of a clonal proliferation of LCs. 1 It has been recently proposed that similar to the unification of LCH, non-LCH fall along a continuum rather than represent discrete entities.…”

“…[3][4][5][6][7][8][9][10] Furthermore, cases exist that exhibit concomitant lesions of LCH and non-LCH, and cases where LCH cells were converted into mature histiocytes with chemotherapy; thereby providing further evidence that an overlap exists both within and between the various histiocytoses. 5,6,[8][9][10][11][12][13][14][15][16] Herein we present a patient who does not easily fit into either the non-LCH or LCH category, but rather displayed clinical and histologic features that bridged both conditions. Through this novel case we review what is currently known about the various conditions classified under the non-LCH and LCH rubric.…”