Vesicular Langerhans cell histiocytosis--an uncommon variant

Langerhans cell histiocytosis: Skin diseases and visceral lesions

Langerhans cell histiocytosis (LCH) is a rare clonal proliferative disorder that belongs to class I histiocytoses and is characterized by infiltration of one or many organs by Langerhans cells to form granulomas. The literature analysis could identify a lot of etiological, pathogenetic, and trigger factors and mechanisms for LCH development, which determine the diversity of the clinical picture and course of the disease. The clinical manifestations of LCH are very variable and depend on the severity of lesions and the age of patients. In addition to skin lesions, there is involvement of one or more visceral organs. Difficulties in diagnosing the disease lead to statistical variations of LCH in different countries of the world and require more attention by physicians of all specialties.

Self-Healing Congenital Langerhans Cell Histiocytosis Presenting as Neonatal Papulovesicular Eruption

Background:

Congenital self-healing Langerhans cell histiocytosis (CSHLCH) is a rare condition which may present at birth or during the neonatal period. It is usually characterized by the eruption of multiple, disseminated, red-brown papules and nodules which may increase in size and number during the first few weeks of life. Systemic signs are usually absent except for occasional mild hepatomegaly.

Objective:

We present a 3.5-kg male infant who presented at birth with numerous diffuse, erythematous, crusted erosions. He was presumed to have congenital herpes simplex virus (HSV) and was started on IV acyclovir. Histopathologic examination revealed a mixed inflammatory infiltrate with numerous histiocytes which were S-100 and peanut agglutin positive consistent with CSHLCH. Further workup did not reveal any signs of systemic involvement.

Conclusion:

CSHLCH has rarely been reported to present as a papulovesicular eruption at birth. In these cases, a viral etiology is commonly entertained in the differential diagnosis. Despite the spontaneous regression of skin lesions in CSHLCH, close followup is required to evaluate for systemic signs and symptoms associated with latent Letterer–Siwe disease.

Solitary Type of Congenital Self-healing Reticulohistiocytosis

Congenital self-healing reticulohistiocytosis is a rare, congenital, benign, self-healing variant of Langerhans cell histiocytosis. It usually appears as multiple papules or nodules; however, occurrence of the solitary type is very rare. We report on a case of solitary congenital self-healing reticulohistiocytosis in a 29-day-old girl who presented with a papule on her sole. Two months later, the lesion regressed with a slight scar. Based upon clinical and histologic findings, we made a diagnosis of solitary congenital self-healing reticulohistiocytosis. In this report, we summarized reported cases of solitary congenital self-healing retioculohistiocytosis in Korea with a review of the literature.

Solitary congenital self-healing reticulohistiocytosis in monozygotic twins

We report monozygotic twins with congenital self-healing reticulohistiocytosis, whose lesions initially presented as hemorrhagic bullae at birth with rapid progression into crusted papules the following day. Physical examination disclosed crusted papules on the right side of the neck of twin 1 and a similar solitary lesion on the lateral side of the right thumb of twin 2. Excisional biopsy specimen findings of the neck and thumb lesions were consistent with Langerhans cell histiocytosis, which was further confirmed by positive CD1a staining. The lesions resolved completely by 2 months with no evidence of recurrence or systemic involvement. Congenital self-healing reticulohistiocytosis is a rare, self-limited form of Langerhans cell histiocytosis. Although familial clustering in Langerhans cell histiocytosis was previously reported, to the best of our knowledge there is no report suggesting familial clustering in congenital self-healing reticulohistiocytosis. Our patients are interesting in terms of raising the question of whether the presence of congenital self-healing reticulohistiocytosis in monozygotic twins is implicative of a genetic role in its pathogenesis.

Congenital systemic Langerhans cell histiocytosis presenting as hydrops fetalis

Congenital Langerhans cell histiocytosis (LCH) encompasses a wide spectrum of disease involvement and severity. Congenital "self-healing" cutaneous LCH represents one end of the spectrum, whereas the case we encountered represents the other extreme. A rare case of congenital LCH with severe multiorgan involvement presenting as hydrops fetalis is described in this report. Hydrops fetalis has not previously been associated with congenital LCH. The overall clinical features of this infant closely mimicked those of disseminated congenital infection, and he ran a fulminant and rapidly fatal course.

CONCLUSION

A high index of suspicion is required to diagnose congenital LCH in the early neonatal period. Hydrops fetalis is an ominous sign and probably reflects severe systemic disease compromising the well-being of the fetus.

Acquired disorders of elastic tissue: Part II. decreased elastic tissue

Elastic fibers in the extracellular matrix are integral components of dermal connective tissue. The resilience and elasticity required for normal structure and function of the skin are attributable to the network of elastic tissue. Advances in our understanding of elastic tissue physiology provide a foundation for studying the pathogenesis of elastic tissue disorders. Many acquired disorders are nevertheless poorly understood owing to the paucity of reported cases. Several acquired disorders in which loss of dermal elastic tissue produces prominent clinical and histopathologic features have recently been described, including middermal elastolysis, papular elastorrhexis, and pseudoxanthoma-like papillary dermal elastolysis, which must be differentiated from more well-known disorders such as anetoderma, acquired cutis laxa, and acrokeratoelastoidosis. Learning objective At the conclusion of this learning activity, participants should have an understanding of the similarities and differences between acquired disorders of elastic tissue that are characterized by a loss of elastic tissue.

Congenital self-healing reticulohistiocytosis presenting with hemorrhagic bullae

Congenital self-healing reticulohistiocytosis is a variant of Langerhans cell histiocytosis. It is present at birth or appears in the neonatal period and involutes spontaneously within 3 to 4 months. Although the skin eruptions in most cases consist of papulonodules, several patients with vesicular or bullous lesions have been reported. We describe a case of congenital self-healing reticulohistiocytosis presenting hemorrhagic bullae that mimicked hemangioma.

Congenital self-healing langerhans cell histiocytosis with atrophic recovery of the skin: clinical correlation of an immunologic phenomenon

The pathophysiology and pathogenesis of congenital self-healing Langerhans cell histiocytosis (CSHLCH) as well as that of the other types of Langerhans cell histiocytosis is not well understood. Some authors postulate deregulated immunologic mechanisms that result in overproduction of cytokines. We examined a neonate with disseminated papulonodular eruptions containing lymphoid aggregates of B lymphocytes in the chorial layer. The diagnosis of a CSHLCH was made and the follow-up showed a complete involution of the eruptions, leaving atrophic lesions in the sites corresponding to the initial findings. We discuss a possible imbalance of the immune response as a pathogenetic mechanism.