Lymphatic vessels are routes for leukocyte migration and fluid drainage. In addition to their passive roles in migration of leukocytes, increasing evidence indicates their active roles in immune regulation. Tissue inflammation rapidly induces lymphatic endothelial cell proliferation and chemokine production, thereby resulting in lymphangiogenesis. Furthermore, lymphatic endothelial cells induce T cell tolerance through various mechanisms. In this review, we focus on the current knowledge on how inflammatory cytokines affect lymphangiogenesis and the roles of lymphatic vessels in modulating immune responses.
Cytokines ; Drainage ; Emigration and Immigration ; Endothelial Cells ; Inflammation ; Leukocytes ; Lymphangiogenesis ; Lymphatic Vessels*

Setleis syndrome, also known as the focal facial dermal dysplasia type 3, is characterized by atrophic scar-like lesions in both the temporal regions and other facial abnormalities. The syndrome is associated with a mutation in the TWIST2 gene and is inherited as an autosomal recessive pattern. Here, we describe a case of an 18-year-old woman and her 10-year-old brother with bitemporal depressed patches. The lesions were observed at birth, but they were replaced by atrophic patches after several months. No abnormalities in growth or development were observed. Histopathologic findings showed atrophy of the epidermis and loss of appendages, such as hair follicles and adnexal glands, in the atrophic patches compared to that of the adjacent normal skin.

Background: A minority of infantile hemangiomas showing minimal or arrested growth (IH-MAGs) have been recognized in the literature. Nevertheless, the clinical features and treatment outcomes of IH-MAGs have not been well investigated. Objective: This study aimed to understand the clinical characteristics of IH-MAGs better and their response to treatment with topical timolol maleate. Methods: We retrospectively reviewed medical records and clinical images of patients with IH-MAGs. Treatment response with topical timolol was assessed in both IH-MAGs and classic infantile hemangiomas (IHs) groups. Results: Of the 1,038 patients with IHs, only 31 (3.0%) were diagnosed with IH-MAGs. Lesions with non-proliferative components were more frequently distributed in the lower half of the body (61.5%) than those with proliferative components (16.7%). In 14 patients treated with topical timolol, the global assessment scale showed more significant and rapid improvement than in those with classic IHs. Conclusion Although the prevalence of IH-MAGs may be relatively low, understanding their clinical features will help in differential diagnosis. Furthermore, these type of lesions might be more responsive to topical timolol than classic IHs.

Cutaneous pseudolymphoma, also referred to as cutaneous lymphoid hyperplasia or lymphocytoma cutis, is an uncommon lymphoproliferative condition. Most lesions are idiopathic in origin; however, triggers such as tattoos, acupuncture, or venipuncture are known to be associated with pseudolymphomas. Owing to the widespread popularity of cosmetic piercings, post-piercing pseudolymphomas are being reported in recent times. Anatomically, most lesions appear on the ears and present with a variety of morphological features, although diagnosis is based on distinctive clinical findings. In this case series, we report four cases of post-piercing pseudolymphoma on the earlobe together with a literature review. We emphasize close and careful monitoring to differentiate this rare condition from other lesions of the earlobe. In view of the diverse clinical presentations and treatment approaches available for pseudolymphomas, we highlight some preliminary clinical indicators to enable early diagnosis and prompt treatment of this condition.

Background: A minority of infantile hemangiomas showing minimal or arrested growth (IH-MAGs) have been recognized in the literature. Nevertheless, the clinical features and treatment outcomes of IH-MAGs have not been well investigated. Objective: This study aimed to understand the clinical characteristics of IH-MAGs better and their response to treatment with topical timolol maleate. Methods: We retrospectively reviewed medical records and clinical images of patients with IH-MAGs. Treatment response with topical timolol was assessed in both IH-MAGs and classic infantile hemangiomas (IHs) groups. Results: Of the 1,038 patients with IHs, only 31 (3.0%) were diagnosed with IH-MAGs. Lesions with non-proliferative components were more frequently distributed in the lower half of the body (61.5%) than those with proliferative components (16.7%). In 14 patients treated with topical timolol, the global assessment scale showed more significant and rapid improvement than in those with classic IHs. Conclusion Although the prevalence of IH-MAGs may be relatively low, understanding their clinical features will help in differential diagnosis. Furthermore, these type of lesions might be more responsive to topical timolol than classic IHs.

Background: Scar sarcoidosis (SS), a rare form of cutaneous sarcoidosis, develops from preexisting scars. Owing to its rarity, the clinicopathologic features and its significance in clinical prognosis have been obscure. Objective: This study aimed to investigate clinical, laboratory and histopathologic findings and to clarify characteristics associated with the development of SS and systemic involvement. Methods: We retrospectively assessed clinical, laboratory and histopathologic findings of SS. Clinical factors including demographics, anatomic area, number of lesion (single, multiple), presence of symptoms, latent period, injury types related to scar and the proportion of systemic involvement were investigated. Results: Of the 21 patients with SS, skin lesions appeared predominantly in females (85.7%) and in the head and neck (57.1%). The mean latent period was 163.5 months and 13 patients (61.9%) had multiple lesions. Injury types were varied, with no specific type identified as associated with SS. Histologically, discrete sarcoidal granulomas surrounded by densely packed collagen bundles with a thickening of numerous fibers were observed. Ten patients (47.6%) had systemic involvement and showed significantly more of the multiple lesions, longer latent period and higher level of mean serum angiotensin-converting enzyme than those without systemic involvement. Conclusion Various causes of scar were related to SS, but no specific injury type was identified as leading to SS. Although the exact pathomechanism remains unclear, the possibility of systemic involvement could be considered when the patients have multiple lesions, longstanding scars, and elevated serum angiotensin-converting enzyme.

Cutaneous pseudolymphoma, also referred to as cutaneous lymphoid hyperplasia or lymphocytoma cutis, is an uncommon lymphoproliferative condition. Most lesions are idiopathic in origin; however, triggers such as tattoos, acupuncture, or venipuncture are known to be associated with pseudolymphomas. Owing to the widespread popularity of cosmetic piercings, post-piercing pseudolymphomas are being reported in recent times. Anatomically, most lesions appear on the ears and present with a variety of morphological features, although diagnosis is based on distinctive clinical findings. In this case series, we report four cases of post-piercing pseudolymphoma on the earlobe together with a literature review. We emphasize close and careful monitoring to differentiate this rare condition from other lesions of the earlobe. In view of the diverse clinical presentations and treatment approaches available for pseudolymphomas, we highlight some preliminary clinical indicators to enable early diagnosis and prompt treatment of this condition.