Related Experiment Video
Updated: Mar 24, 2026

An Immunohistopathologic Study to Profile the Folate Receptor Beta Macrophage and Vascular Immune Microenvironment in Giant Cell Arteritis
Published on: February 8, 2019
Generalized granuloma annulare in a folliculocentric distribution
Lisa R Rothman1, Adnan Mir, Shane A Meehan
1New York University School of Medicine.
Abstract:
We present a 69-year-old man with type 2 diabetes mellitus and a five-year history of an eruption of follicular pustules, papules, and nodules, which was identified histopathologically as folliculocentric granuloma annulare (GA). Folliculocentric generalized GA is a rarely reported variant of GA, in which the the palisading histiocytes form focal granulomas in a follicular pattern. In this case, the GA may represent an isotopic phenomenon, with lesions developing in hair follicles that were previously affected by a suppurative folliculitis.
Related Concept Videos
Folliculogenesis
Papillary Dermis
The dermis might be considered the "core" of the integumentary system, as distinct from the epidermis and hypodermis. It contains blood and lymph vessels, nerves, and other structures, such as hair follicles and sweat glands. The dermis is made of two layers of connective tissue that comprise an interconnected mesh of elastin and collagenous fibers, produced by fibroblasts.
Papillary Layer
The papillary layer is made of loose, areolar connective tissue, which means the collagen...
Secondary Lymphoid Organs
The spleen is a vital organ in the lymphatic system, nestled in the upper left side of the abdomen. It is composed of two primary regions: the red pulp and the white pulp, each having distinct functions. The red pulp performs a significant role in blood filtration. It efficiently purges the blood of old or damaged red blood cells and...
Reticular Dermis
Reticular Layer
Underlying the papillary layer is the much thicker reticular layer, composed of dense, irregular connective...
Primary Lymphoid Organs
The red bone marrow is a soft, spongy tissue nestled in the interior of long bones such as the humerus and femur. It is the site...
Detailed Structure and Function of Lymph Nodes
From a histological perspective, lymph nodes can be split into two main areas: the superficial cortex and the deep medulla. The outer cortex is populated by dendritic cells, macrophages, and B lymphocytes, which are densely packed into follicles. When these B-lymphocytes are presented...

