Dermatofibroma with diffuse eosinophilia

ARTICLE

Auteur(s) : Hetal TALATI¹, Dina EL DEMELLAWY² eldemeld@gmail.com, Jan JANSEN¹, Salem ALOWAMI¹

¹ Department of Pathology and Molecular Medicine, McMaster Health Sciences Centre, McMaster University, Hamilton, Ontario, Canada

² Department of Pathology and Laboratory Medicine, Northern Ontario School of Medicine, William Osler Health Centre, Brampton, Ontario, Canada

We report a case of a healthy 9-year-old girl who presented with a small, well circumscribed lesion on the posterior parietal scalp. The lesion was asymptomatic but grew larger two years later. There was no history of trauma, allergies or insect bite. Complete blood count and differential count was normal. The lesion was excised in elliptical fashion and sent for histopathological examination. Gross examination showed a 1.6 × 0.9 × 0.6 cm circumscribed firm nodule with a homogenous yellow-brown cut surface. Microscopic examination revealed epidermal hyperplasia. The reticular dermis and subcutis showed an ill-defined nodule composed of spindle cell proliferation, entrapped collagen fibres, foam cells, occasional lymphoid aggregates and diffuse eosinophilic infiltrate (figures 1A, B). Immunohistochemistry stains were performed. Lesional cells were negative for CD34, S-100, CD1a, CD15, CD30, AE1/AE3 and CAM 5.2 and positive for factor XIIIa, CD68 and vimentin, confirming the diagnosis of dermatofibroma. The patient required no further therapy and is doing well with no evidence of recurrence during the follow-up one year period.

Eosinophilic infiltrate is highly uncommon in dermatofibroma. Only three cases have been described in the literature [1-3](table 1). Differential diagnosis of dense dermal eosinophilic infiltrate includes history of insect bite, allergies and hypereosinophilic syndrome, which was not present in our case. Other histological differential diagnoses include angiolymphoid hyperplasia with eosinophilia, Kimura's disease, eosinophilic cellulitis, langerhans cell histiocytosis and Hodgkin's disease.

Table 1 Summary of clinical findings of cases of dermatofibroma with diffuse eosinophilia reported in the English literature.

NA: Information not available

Factor XIIIa, vimentin and CD-68 positivity, associated with negativity for CD1a, S100, CD30 and CD15 confirmed the diagnosis of dermatofibroma.

Disclosure

Financial support: none. Conflict of interest: none.

References

1 S Aiba, T Terui, H. Tagami Dermatofibroma with diffuse eosinophilic infiltrate Am J Dermatopathol 2000; 22: 281-284.

2 CDM Fletcher, D. Lowe Inflammatory fibrous histiocytoma of the penis Histopathology 1984; 8: 1079-1084.

3 S Eduardo, M Amalia, R Beatriz et al. Benign fibrous histiocytoma with intermediate cells and eosinophils Am J Dematopathol 2004; 26: 237-241.