American Journal of Dermatopathology:
Letters to the Editor
Kim, Cho Rok MD; Kim, Hyun-je MD; Jung, Mi-young MD; Lee, Jae-hyung MD; Lee, Dong-Youn MD, PhD; Lee, Joo-Heung MD, PhD; Yang, Jun-Mo MD, PhD; Lee, Eil-Soo MD, PhD
Department of Dermatology Sungkyunkwan University School of Medicine Samsung Medical Center Seoul, Korea
The authors have no funding or conflicts of interest to declare.
To the Editor:
Spindle cell xanthogranuloma (SCXG) is a rare variant of juvenile xanthogranuloma.1 Usually SCXG develops in adults and less commonly in children. Clinically, SCXG presents with yellowish to brownish papules and often involves head, neck and upper portion of trunk, but it can also affect the extremities.2 Histologically, SCXG is characterized by dense cellular infiltrates composed mainly of spindle cell histiocytes.
An 11-month-old infant presented with a yellowish to brownish dome-shaped papule on the occiput which had been present since birth. During this time, the lesion gradually increased in size. The patient was born at term and was otherwise healthy; parents denied taking any drugs during the pregnancy. Neither the parents nor other members of her family reported any episode of xanthogranuloma. Physical examination revealed an well-demarcated distinct firm yellowish to brownish dome-shaped papule on the scalp (Fig. 1). The rest of the physical examination was unremarkable.
Histological examination of the biopsy taken from the lesion showed a dense histiocytic cell proliferation occupying the dermis with a storiform pattern. Numerous eosinophils were noted in the lower dermis (Fig. 2A–C). Immunohistochemically, the neoplastic cells were strongly positive for CD 68 (Fig. 3A) and HLA-DR (Fig. 3B), however the cells were negative for S-100, Factor XIIIa, and CD 1a (Fig. 3C). Based on the clinical and histological findings, this case was diagnosed as spindle cell xanthogranuloma. Close follow-up of the patient is planned to monitor any change in size.
Spindle cell xanthogranuloma is a rare variant form of juvenile xanthogranuloma. It presents with a well demarcated nodule composed predominantly of spindle-shaped histiocytes in a storiform arrangement. Usually, SCXG develops in young adult and it is clinically characterized by a yellow to brownish papule. It commonly affects head, neck, and upper portion of trunk. Less common sites include extremities.2
Twelve cases of solitary spindle cell xanthogranuloma were described in 1995 by Zelger et al.3 Thereafter, only a handful cases of solitary spindle cell xanthogranuloma have been reported, however, no congenital cases have been previously reported. This is the first case of congenital solitary spindle cell xanthogranuloma.
The main differential diagnosis with dermatofibroma. According to Zelger et al,3 7 of their 12 cases had originally been misdiagnosed as dermatofibroma/benign fibrous histiocytoma. Clinically, SCXG can mimic dermatofibroma (DF), and histologically both disease can show a storiform arrangement of spindle cells. However, dermatofibroma typically develops on the legs of middle-aged women.
Several histopathological findings such as marked epidermal hyperplasia including increased basal pigmentation, elongation of rete ridge associated with peripheral sclerotic collagen bundles, favor the diagnosis of dermatofibroma rather than SCXG. In the case of dermatofibroma, macrophages and multinucleated giant cells can be seen, but not as predominant as in SCXG. Immunohistochemical stains stain for macrophages such as CD 68 and Mac 387, are usually negative in dermatofibroma but are strongly positive in SCXG. Furthermore, in dermatofibromas, Factor XIIIa stain is usually positive; and negative in SCXG. Factor XIIIa stain was negative in our case.
Progressive nodular histiocytosis should also be considered in the differential diagnosis, It shares common features such as the presence of Touton type multinucleated giant cells and a, storiform arrangement of spindle cells. Unlike SCXG, progressive nodular histiocytosis usually develops in older adults and shows a disseminated distribution.
In our case, numerous eosinophils were noted in the deep dermis, which is an atypical finding in SCXG.
We will monitor this patient to detect any progression or change of the lesion, considering the possibility of progression of SCXG to progressvie nodular histiochytosis.
In conclusion, SCXG is a very rare variant of juvenile xanthogranuloma, and clinician should consider the possibility SCXG in the differential diagnosis of dermatofibroma, progressive nodular histiocytosis, and JXG, because both clinically and histologically SCXG can mimic these diseases.
1. Zelger BW, Sidoroff A, Orchard G, et al.. Non-Langerhans cell histocytoses. A new unifying concept. Am J Dermatopathol. 1996; 18:490–504.
2. DeStafeno JJ, Carlson JA, Meyer DR. Solitary spindle-cell xanthogranuloma of the eyelid. Opthalmology. 2002;109:258–261.
3. Zelger BW, Staudacher C, Orchard G, et al.. Solitary and generalized variants of spindle cell xanthogranuloma (progressive nodular histiocytosis). Histopathology. 1995;27:11–19.
© 2012 Lippincott Williams & Wilkins, Inc.