Langerhans cell histiocytosis of the skull on cytologic squash preparations

Abstract

We present a case in which a primary cytodiagnosis of Langerhans cell histiocytosis (LCH) of the skull was made using squash preparations. The patient, a 25-year-old male, presented with raised intracranial pressure and decreased visual acuity. Magnetic resonance imaging revealed a large skull lesion with osteolytic features in the left frontal bone. The patient underwent surgical resection by the extended basal frontal epidural approach. The squash preparation smears were cellular and demonstrated a mixed population of small, mature lymphocytes, eosinophils, and a high histiocytes content. The histiocytes occurred as isolated or loosely cohesive and clustered. They possessed abundant cytoplasm with rounded cell shape and had characteristic nuclear features, composed of fine chromatin and delicate nuclear membranes. The cytologic features of these histiocytes were consistent with Langerhans cells (LCs). A final impression of LCH of the skull was rendered. Subsequent histopathology confirmed the diagnosis. LCs reacted with both S-100 protein and CD1a immunohistochemically. The demonstration of Birbeck granules on electron microscopic study was also noted. Whenever squash preparation yields a mixed population of mature lymphocytes, eosinophils, and histiocytes, the cytologists should be aware of and consider LCH as a diagnostic possibility.

Cytologic Diagnosis of Central Neurocytoma in Intraoperative Squash Preparations

“…11,12 Cytologic preparations were hypercellular in the 2 cases examined ( Figure 1). The predominant morphology (or common morphologic denominator) was sheets of uniform, round, oligodendrocytelike cells with perinuclear halos (so-called fried-egg appearance) ( Figure 2) in both cases.…”

Endocrine manifestations of Langerhans cell histiocytosis diagnosed in adults

“…Histologically, LCH is characterized by large cells with abundant cytoplasm within a background of lymphocytes and eosinophils. Findings of this type should prompt confirmation of the LCH diagnosis by means of electron microscopy, where Birbeck granules (cytoplasmic inclusions with inner serrations and occasional terminal dilations) are seen, or a positive immunohistochemistry for S100 protein and CD1a [1,5,6,15,16].…”

“…However, primary thyroid involvement is extremely rare [5,8]. Diagnosis is based on electronic microscopy (Birbeck granules) or immunohistochemistry (positivity for S100 protein and CD1a) [1,5,6,15,16]. The choice of treatment is based on the extent of the disease and the site of involvement [5,17].…”

“…Langerhans cell histiocytosis is a rare granulomatous disease of unknown etiology [1] characterized by the idiopathic proliferation of specialized bone marrow-derived Langerhans cells and mature eosinophils. Langerhans cells are immature dendritic cells of epidermis and mucosal tissues [2][3][4].…”

“…Langerhans cells are immature dendritic cells of epidermis and mucosal tissues [2][3][4]. LCH prevalence is 1-2/1,000,000 in children and significantly lower in adults [1,[5][6][7], with no specific gender preference [5,8]. LCH may be systemic or localized [4] and its clinical manifestations are variable [2].…”