Encyclopedia of Pathology

Living Edition
| Editors: J.H.J.M. van Krieken

Benign Fibrous Histiocytoma

  • Alessandro FranchiEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-28845-1_4785-1

Synonyms

Definition

Benign fibrous histiocytoma is a cutaneous tumor with predominantly dermal involvement, mainly composed of cells with fibro-histiocytic differentiation.

Clinical Features

  • Incidence

    In general, BFH is a very common neoplasm, but involvement of the scrotum and the penis is exceedingly rare (Dehner and Smith 1970; Kinoshita et al. 1985; Huan et al. 2003).

  • Age

    It may occur at any age, but it is most common in adults.

  • Treatment

    The treatment of choice is surgical excision.

  • Outcome

    Complete surgical excision is usually curative.

Macroscopy

BFH appears as a firm, non-encapsulated lesion of the dermis, with white to yellow cut surface. Cystic changes and hemorrhage may be present.

Microscopy

Histologically, there is a dermal-centered proliferation of bland spindle fibroblast-like cells and of histiocytoid cells, entrapping thick collagen fibers, especially at the periphery of the tumor (Fig. 1). The overlying epidermis is hyperplastic and presents hyperpigmentation of the basal layer. Early lesions are typically more cellular, while older ones are more fibrotic. Fibroblast-like cells are elongated, with eosinophilic cytoplasm, and histiocytoid cells are larger, with abundant pale vacuolated cytoplasm. Few lymphocytes may also be present in the early lesions. Cytologic atypia is usually absent, except for the “atypical” or “pseudosarcomatous” variant, which presents larger cells with nuclear hyperchromasia and prominent nucleoli (Huan et al. 2003). Several other variants are recognized, but they have not been reported in the genital area.
Fig. 1

Benign fibrous histiocytoma composed mainly of bland histiocytoid cells with pale eosinophilic cytoplasm and oval nucleus with small nucleolus. Thick collagen fibers are present within the proliferation

Immunophenotype

BFH is positive for vimentin, CD68, and factor XIIIa. A minor population of actin-positive myofibroblasts may be present. CD34 is negative.

Differential Diagnosis

The main differential diagnosis is with dermatofibrosarcoma protuberans. This shows extension in the subcutaneous fat with entrapment of single adipocytes, consists of a monomorphous population of spindle cells, and is positive for CD34. The atypical variant of BFH should not be confused with a pleomorphic sarcoma. Atypical mitoses and necrosis are absent in BFH.

References and Further Reading

  1. Dehner, L. P., & Smith, B. H. (1970). Soft tissue tumors of the penis. A clinicopathologic study of 46 cases. Cancer, 25, 1431–1447.CrossRefGoogle Scholar
  2. Huan, Y., Vapnek, J., & Unger, P. D. (2003). Atypical fibrous histiocytoma of the scrotum. Annals of Diagnostic Pathology, 7, 370–373.CrossRefGoogle Scholar
  3. Kinoshita, H., Okada, K., Nagata, Y., & Kawamura, N. (1985). Fibrous histiocytoma of penis. Urology, 25, 544–546.CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.Department of Translational Research and of New Technologies in Medicine and SurgeryUniversity of PisaPisaItaly