PEDIATRIC DERMATOLOGY:
What's your Dx?

Sole manifestation: Nodule in a newborn boy

By Bernard A. Cohen, MD

An ulcerated nodule was noted on the sole of this healthy 2-week-old boy at birth (Figure 1). The nodule did not seem tender and, since birth, had flattened slightly. The mother's pregnancy, labor, and delivery were uncomplicated. The boy had gained nearly a pound since being discharged from the nursery.

• What is your diagnosis?

• How would you evaluate this infant?

Diagnosis: Self-healing reticulohistiocytosis

Skin biopsy revealed an ulcerated nodule comprising primarily histiocytes and lymphocytes and extending into the deep dermis. Testing for immunohistochemical markers was positive for protein S100 and CD1a antigen, expressed as Langerhans cell histiocytes.^1,2

Evaluation. A complete physical examination failed to reveal evidence of visceral involvement: Specifically, the infant had neither hepatosplenomegaly nor lymphadenopathy. Chest radiographs and a skeletal survey were negative. A complete blood count and liver function tests were normal.

Natural history. Self-healing reticulohistiocytosis is a generally benign, self-limited variant of Langerhans cell histiocytosis. Characteristics of self-healing reticulohistiocytosis are:

• the presence of a regressing solitary, ulcerated nodule

• typical histologic findings with histochemical markers

• the absence of systemic disease.

This disorder was initially described by Hashimoto and Pritzker in 1973 in a child who had many congenital cutaneous nodules, all of which resolved within the first few weeks of life.² Biopsy showed histologic markers of Langerhans cell histiocytes, including typical Bierback granules (Figure 2) in 10% of infiltrating cells.^1,2

The nodules appear as solitary or only a few lesions. Many reddish-purple nodules, however, can appear on patients with the congenital form of self-healing reticulohistiocytosis. The diameter of the nodules ranges from 0.5 to 2 cm, and the nodules regress over a few days or months. Often, the nodules develop central necrosis with a peripheral rolled edge.

Prognosis. Affected infants do not usually develop systemic disease, but there is considerable overlap among self-healing reticulohistiocytosis and other benign cutaneous and systemic histiocytic disorders.^1–3 Consequently, the pediatrician must be careful when counseling parents about prognosis.

A small percentage of patients do develop systemic disease, or limited visceral involvement, months or years later. This happens even when there is no evidence of hepatosplenomegaly or lymphadenopathy, and when imaging studies (including a chest radiograph and a skeletal survey) are negative and laboratory tests (liver function tests and a CBC) are normal. Regular monitoring of growth and development during childhood and observing the patient for signs of systemic disease are required.

Differential diagnosis. A solitary ulcerated nodule in a newborn presents a broad differential diagnosis that includes congenital leukemia, lymphoma, and a number of rare metastatic solid tumors, including neuroblastoma, adrenal carcinoma, and renal carcinoma. A solitary mastocytoma may present as an isolated ulcerated nodule. You will also need to exclude primary vesiculobullous eruptions such as varicella, bullous impetigo, and herpes simplex virus infection.⁴

Outcome. The nodule in this patient resolved with minimal atrophy by 4 months of age. At 6 months, he is thriving without evidence of systemic disease.

REFERENCES

1. Hashimoto K, Takahashi S, Lee RG, et al: Congenital self-healing reticulohistiocytosis: Report of the seventh case with histochemical and ultrastructural studies. J Am Acad Dermatol 1984;11(3):447

2. Hashimoto K, Pritzker MS: Electron microscopic study of reticulohistiocytoma: An unusual case of congenital self-healing reticulohistiocytosis. Arch Dermatol 1973; 107(2):263

3. Jang KA, Ahn SJ, Choi JH, et al: Histiocytotic disorders with spontaneous regression in infancy. Pediatr Dermatol 2000;17(5):364

The next installment of Pediatric Dermatology: What's your Dx? will appear in January 2003

For this case and related images, or to contribute new images from your own cases, see Dr. Cohen's Web site at www.med.jhu.edu/peds/dermatlas .

DR. COHEN, who serves as section editor for Pediatric Dermatology: What's your Dx?, is director, Pediatric Dermatology and Cutaneous Laser Center, and associate professor of pediatrics and dermatology at Johns Hopkins University School of Medicine, Baltimore. He is a contributing editor for Contemporary Pediatrics.

 

Bernard Cohen. Pediatric dermatology: What's your Dx? Contemporary Pediatrics October 2002;19:43.