Ulcerated dermatofibroma with osteoclast-like giant cells

Cutaneous Fibrous Histiocytomas, Ossifying-Variant with Osteoclast-like Giant Cells and Granular Cell-Variant: A Series of Two Unusual Cases with Emphasis on the Differential Diagnosis

The ossifying variant and the granular cell variant are rare subtypes of cutaneous fibrous histiocytoma (CFH), characterized by islands of mature metaplastic bone tissue rimmed by multinucleated osteoclast-like giant cells and by large-sized cells with granular cytoplasm and mildly hyperchromatic nuclei with inconspicuous nucleoli, respectively. We herein present two cases of these unusual CFH variants in a 37-year-old woman and in a 38-year-old man, respectively. The main differential diagnoses, including both benign and malignant lesions, are also discussed.

Osteoclast-Like Giant Cells: Focus on Entities Relevant to Dermatopathology and Underlying Pathogenesis

ABSTRACT

Osteoclast-like giant cells (OLGCs) resemble osteoclasts with their abundant cytoplasm and well-developed organelles. OLGCs are characteristic features of giant cell tumor of the tendon sheath and giant cell tumor of soft tissue but they have also been described in numerous other cutaneous conditions. The diagnostic and prognostic significance of the presence of OLGCs is unknown. Here, we summarize the clinical entities that can exhibit these cells to avoid a histological overlap, affecting diagnosis and management.

Ulcerated Giant Dermatofibroma following Routine Childhood Vaccination in a Young Boy

Introduction

The development of cutaneous neoplasms at immunization sites following vaccination is uncommon, and only few have been reported in the literature worldwide. We report an unusual case of an ulcerated giant dermatofibroma that developed as a chronic nonhealing plaque in the immunization scar of a young boy after vaccination.

Case Report

A 13-month-old Chinese boy presented with an unusual skin reaction on the vaccination site at the right anterolateral thigh following a routine intramuscular injection of ‘5-in-1’ (diphtheria, tetanus, pertussis, polio and Haemophilus influenzae B) vaccine at 4 months of age. The immunization site developed a slightly raised papule with a central punctum that progressively grew in size, ulcerated and showed occasional bleeding over a span of 9 months. On follow-up, the lesion showed a chronic granulomatous reaction with surrounding induration and a central scarring. The right inguinal lymph node was palpable. Ultrasound of the lesion showed only nonspecific focal skin thickening. An incisional skin biopsy with careful histopathological evaluation revealed microscopic features consistent with an ulcerated giant dermatofibroma.

Conclusion

Neoplastic development in immunization scars following vaccination is a rare occurrence and, hence, makes this case a diagnostic challenge. A high index of suspicion is crucial in atypical presentations of a common skin lesion, as typified by this case. Careful history taking and clinicopathological correlation of clinical findings with gross and microscopic findings along with targeted immunohistological staining is often essential to aid early diagnosis.

Nonepithelial skin tumors with multinucleated giant cells

Recognition of the different types of multinucleated giant cells in neoplastic and pseudotumoral lesions of the skin may be helpful in the differential diagnosis of these tumors. In this review, we will analyze the different types of multinucleated giant cells that can be found in nonepithelial cutaneous tumors and, more importantly, the clinicopathological context in which they are found. Touton giant cells are typically present in juvenile xanthogranuloma, necrobiotic xanthogranuloma, and some subtypes of xanthomas. Giant cells with a ground glass appearance are typically present in the solitary reticulohistiocytoma and multicentric reticulohistiocytosis. Osteoclast-like cells are found in giant cell tumors (GCT) of soft parts, plexiform fibrohistiocytic tumor, and atypical fibroxanthoma. Floret-like cells are present in giant cell fibroblastoma, pleomorphic lipoma, multinucleate cell angiohistiocytoma, and giant cell collagenoma.