Non-Langerhans Cell Histiocytoses

Abstract

Based on our series of 111 cases of non-Langerhans cell histiocytoses, we present a new unifying concept for this rare group of disorders. The common denominator is the monocyte/ macrophage, which presents with various histologic features probably due to the influence of cytokines. Non-Langerhans cell histiocytoses are classified according to the predominant mononuclear (vacuolated, spindle-shaped, xanthomatized, scalloped, and oncocytic) and/or multinucleate (Touton, ground-glass appearance, Langhans, and foreign body) histiocytic cell types. Variable mixtures of these cell types produce common polymorphous patterns with prominence of vacuolated, spindle-shaped, and xanthomatized histiocytes in juvenile xanthogranulomas and of scalloped and oncocytic histiocytes in adult xanthogranulomas. Rarely, unusual monomorphous reaction patterns are observed: mostly vacuolated histiocytes are seen in the mononuclear variant of xanthogranulomas, (early benign cephalic histiocytosis, and generalized eruptive histiocytoma. Xanthomatized histiocytes predominate papular xanthoma and rarely xanthoma disseminatum, whereas spindle-shaped histiocytes are evident in spindle cell xanthogranuloma and progressive nodular histiocytosis, scalloped histiocytes are evident in most cases of xanthoma disseminatum, and finally oncocytic histiocytes are evident in reticulohistiocytoma and multicentric histiocytosis. Immunohistochemical, ultrastructural, and clinical findings can rationally be adjusted to this unifying concept of non-Langerhans cell histiocytoses. The time course of lesions, the age of the patients, and the presence or absence of underlying internal diseases are, or may, at least partially, be related to and thus explain variations on the theme of the non-Langerhans cell histiocytic reaction.

Papular Xanthoma Associated with Angiokeratoma of Fordyce: Considerations on the Nosography of This Rare Non-Langerhans Cell Histiocytoxanthomatosis

“…Since the histological and immunocytochemical features of many xanthomized non-LC histiocytoses (juvenile xanthogranuloma, PX, xanthoma disseminatum and PNH) may be very similar [18, 19, 20]and since nonxanthomized non-LC histiocytoses like benign cephalic histiocytosis and generalized eruptive histiocytosis can transform into xanthomized non-LC histiocytosis [22, 23, 24, 25, 26], the exact diagnosis of these overlapping diseases is in many cases mainly based on clinical findings. Clinically, xanthoma disseminatum differs from PX because of (a) the tendency of the lesions to become confluent and to merge into plaques; (b) the involvement of skin folds and mucous membranes and (c) the association with diabetes insipidus [27].…”

Progressive nodular histiocytosis

“…The presence of histiocytic infi ltrates occurs in all forms and is characterized by spindle-shaped, vacuolated, stellate, oncocytic (ground-glass) and foamy cells, all of which express immunohistochemical macrophage markers such as CD68 and CD163. Dendritic cells are also occasionally involved [3][4][5][6][7][8][9][10][11]. Table 1 Xanthogranuloma group of non-Langerhans cell histiocytoses (based on [7]).…”

Cutaneous Rosai-Dorfman Disease With Increased Number of Eosinophils: Coincidence or Histologic Variant?

“…This collection of cutaneous histiocytic disorders can display a wide variety of morphologic characteristics, including mononuclear cells that may be vacuolated, xanthomatous, spindle-shaped (all characteristically found in juvenile xanthogranulomas), and display oncocytic changes (more commonly seen in adult xanthogranulomas). 6 Although multinucleated giant cells are often found and help classify the disorder (Touton giant cells in juvenile xanthogranuloma and Langhans giant cells in adult xanthogranuloma), they are, by no means, specific. Multinucleated giant cells, as well as foamy histiocytes, can be seen in RDD; therefore, the presence or lack of emperipolesis is probably the single most-important histologic feature that can help distinguish RDD and xanthogranulomatous diseases.…”