Desmoplastic fibroblastoma: a light and ultrastructural description of two cases

Dermal desmoplastic fibroblastoma presenting as a large sacral mass

Desmoplastic fibroblastoma (collagenous fibroma) is a rare and recently recognised benign tumour. Most desmoplastic fibroblastomas arise in the subcutaneous tissue or skeletal muscle. Involvement of the dermis is extremely rare. We describe an unusual case of dermal desmoplastic fibroblastoma presenting as a large sacral mass in a 16-year-old male. An awareness of this entity is necessary to avoid confusion with other benign and malignant soft tissue neoplasms.

Desmoplastic (collagenous) fibroma of the femur: A case report and review of the literature

Desmoplastic fibroma is a rare, benign soft-tissue tumor composed of spindled and stellate-shaped cells that are embedded in a dense collagenous stroma. Clinically, desmoplastic fibroma presents as a firm, mobile, slow-growing mass that is located in the subcutaneous tissue or near the deep aspect of the skeletal muscles. The present study describes the case of a 66-year-old female who presented with an inactive, firm, slightly tender mass in the lower medial segment of the right femur. An open biopsy was performed and the result of the pathological examination indicated a desmoplastic fibroma. The patient underwent a radical resection of the tumor and the accompanying bone, which was then reimplanted using devitalized tumor bone, self-ilium graft and homologous allograft bone transplantation, with an internal fixation by locking the compression plate. This was followed by a reconstruction of the anterior and posterior cruciate ligaments and the lateral and medial collateral ligaments. There was no evidence of local recurrence at five years post-surgery.

Natural evolution of desmoplastic fibroblastoma on magnetic resonance imaging: a case report

Introduction

Desmoplastic fibroblastoma (collagenous fibroma) is a recently described tumor thought to arise predominantly from subcutaneous tissue or skeletal muscle. The natural evolution of this tumor on magnetic resonance imaging has never been described, to the best of our knowledge. We herein report a case of desmoplastic fibroblastoma arising in the thigh and show the longitudinal magnetic resonance imaging findings.

Case presentation

A 60-year-old Japanese man presented with swelling of the medial side of his right thigh, and he complained of nighttime pain and slight tenderness. Magnetic resonance imaging demonstrated a 4 × 4 cm mass in the right thigh. Open biopsy was performed. The mass was diagnosed histologically as a benign fibrous tumor, and we maintained follow-up without surgical therapy. After one year, magnetic resonance imaging showed an increase in tumor size to 4 × 5 cm, but the histologic findings were the same as those obtained one year earlier. Resection was performed with narrow surgical margins. Pathologic diagnosis was desmoplastic fibroblastoma. Two years after surgery, the patient is free from pain and shows no signs or symptoms of recurrence.

Conclusion

The natural evolution of desmoplastic fibroblastoma is characterized by no changes in patterns on magnetic resonance imaging despite increasing size. This finding is clinically helpful for distinguishing desmoplastic fibroblastoma with increasing pain from the desmoid tumor.

Simian immunodeficiency virus-induced changes in T cell cytokine responses in cynomolgus macaques with latent Mycobacterium tuberculosis infection are associated with timing of reactivation

Understanding the early immunologic events accompanying reactivated tuberculosis (TB) in HIV-infected individuals may yield insight into causes of reactivation and improve treatment modalities. We used the cynomolgus macaque (Macaca fascicularis) model of HIV-Mycobacterium tuberculosis coinfection to investigate the dynamics of multifunctional T cell responses and granuloma T cell phenotypes in reactivated TB. CD4(+) and CD8(+) T cells expressing Th1 cytokines (IFN-γ, IL-2, TNF) and Th2 cytokines (IL-4 and IL-10) were followed from latent M. tuberculosis infection to reactivation after coinfection with a pathogenic SIV. Coinfected animals experienced increased Th1 cytokine responses to M. tuberculosis Ags above the latent-response baseline 3-5 wk post-SIV infection that corresponded with peak plasma viremia. Th2 cytokine expression was not Ag specific, but strong, transient IL-4 expression was noted 4-7 wk post-SIV infection. Animals reactivating <17 wk post-SIV infection had significantly more multifunctional CD4(+) T cells 3-5 wk post-SIV infection and more Th2-polarized and fewer Th0-, Th1-polarized CD8(+) T cells during weeks 1-10 post-SIV infection than animals reactivating >26 wk post-SIV infection. Granuloma T cells included Th0-, Th1-, and Th2-polarized phenotypes but were particularly rich in cytolytic (CD107(+)) T cells. When combined with the changes in peripheral blood T cells, these factors indicate that events during acute HIV infection are likely to include distortions in proinflammatory and anti-inflammatory T cell responses within the granuloma that have significant effects on reactivation of latent TB. Moreover, it appears that mycobacteria-specific multifunctional T cells are better correlates of Ag load (i.e., disease status) than of protection.

Myxoid Epithelioid Sarcoma: Clinicopathologic Analysis of 2 Cases

In the nearly 4 decades since its original delineation as a distinct clinicopathologic entity, several morphologic variations of epithelioid sarcoma have been described. Proximal, angiomatoid, and fibroma-like variants have been reported, as have cases displaying significant hyalinization, calcification, and/or ossification. Furthermore, it has long been recognized that epithelioid sarcoma may display focal myxoid change. Herein, the authors describe 2 examples of epithelioid sarcoma that displayed diffuse myxoid change. Both cases were otherwise typical, both morphologically and immunophenotypically, of epithelioid sarcoma. The tumors in both cases were localized, and the patients were treated with wide local excision followed by adjuvant radiotherapy. The patients are free of disease recurrence after 25 and 37 months of follow-up. Differential considerations that may arise because of the composite of morphologic and immunophenotypic findings noted in these cases are discussed, especially if encountered in a small biopsy. These cases further expand the morphologic spectrum of epithelioid sarcoma.