December 2006

Fig.5

Fig.6

Fig.7

Diagnosis: Congenital self healing reticulohistiocytosis (Hashimoto-Pritzker Syndrome)

Histopathology: Histologic examination of a biopsy specimen from the left arm showed multifocal areas of subcorneal neutrophils and incipient epidermal necrosis/ulceration (figures 4 and 5). In areas of intact epidermis, there were some superficial, vaguely nodular infiltrates of histiocytoid cells with a reniform shape and nuclear groove characteristic of Langerhans cells which was confirmed with positive staining with CD1a (figure 6).

Discussion: Congenital self healing reticulohistiocytosis (CSHR) is in the family of Langerhan cell histiocytoses. CSHR is characterized by red, violaceous, or brown, firm, painless papules that can be distributed over the scalp, face, trunk, extremeties, palms, and soles. Some patients may have a primarily vesicular eruption. Solitary lesions have been described. CSHR presents at birth and resolves within 2 to 3 months. Patients are healthy and without systemic symptoms. At times, it may be difficult to differentiate CSHR from systemic Langerhan cell histiocytosis. Time will differentiate the two, as the former involutes and the infant remains healthy, whereas in the latter, the disease progresses and the infants condition deteriorates. Clues that differentiate CSHR from systemic Langerhan cell histiocytosis at them time of presentation includes the absence of mucosal involvement (only rarely reported) in CSHR and absence of lesions in a seborrheic distribution in CSHR. In addition, the lesions of systemic Langerhan cell histiocytosis are usually monomorphous, whereas those of CSHR are variable.

Histologically, CSHR is characterized by a massive dermal infiltrate of polymorphic histiocytes with abundant ground-glass cytoplasm and kidney-shaped nuclei. Multinucleated giant cells may also exist. The epidermis may show a similar infiltrate and is often ulcerated. Lymphocytes, neutrophils, and eosinophils are commonly seen. Histiocytes stain with the Langerhan cell marker CD1a, as well as S100. Birbeck granules are seen in roughly 10-25% of histiocytes with electron microscopy. The presence of Birbeck granules and laminated dense bodies within the same cell is highly suggestive of CSHR, as opposed to systemic Langerhan cell histiocytosis.

Because differentiation from systemic Langerhan cell histiocytosis is not always possible at presentation, patients should have a complete blood cell count and complete metabolic panel performed. One should consider ultrasound of the liver and spleen, plain films of the skull, chest, and long bones, and bone marrow biopsy as conditions warrant, particularly if the infant is ill or if lesions fail to involute within 3 months. Long-term follow-up is necessary as development of multiorgan involvement within one year of skin lesion resolution has rarely been reported.

References:
1. Ricart J, Jimenez A, Marquina A, Villanueva A. Congenital self-healing reticulohistiocytosis: report of a case and review of the literature. Acta Paediatr. 2004;93(3):426-9.
2. Dermatology. Jean Bolognia, Joseph L Jorizzo, Ronald P Rapini. Elsevier Inc., 2003.

This case was presented by Dr.David Smith. Histology photographs courtesy of Drs. Kimberly Crone and Anne Lind.