Interdigitating reticulum-cell sarcoma of the intestine: a case report and review of the literature.

Dendritic cells are immune accessory cells which are widely distributed in many tissues. Those which are present within lymphoid follicle centers are classified as follicular dendritic cells. Those which are found outside germinal centers may be referred to as interdigitating reticulum cells, or Langerhans cells when they occur in the skin. Abnormal proliferations of dendritic cells are best known as the group of disorders comprising Langerhans-cell histiocytosis, which occurs primarily in children and teenagers. There are increasing reports of malignant proliferations of both types of dendritic cells in adults. However, there is only one previous description of the cytologic features of a dendritic cell sarcoma based on imprint cytology of a resected jejunal mass. The current report provides a detailed description of the cytologic features of a fine-needle aspirate of a recurrence of an interdigitating reticulum-cell sarcoma of the cecum.