Tocilizumab for the treatment of paraneoplastic inflammatory syndrome associated with angiomatoid fibrous histiocytoma

Evidence of Chemoresponsiveness in Unresectable Metastatic Angiomatoid Fibrous Histiocytoma

Angiomatoid fibrous histiocytoma (AFH) is a soft tissue neoplasm of intermediate biological potential. Typically a slow-growing tumor, it can recur locally. Rarely, it manifests as a soft tissue sarcoma capable of metastasis. When metastases are nonamenable to local therapy, it is believed uniformly fatal. We present 3 patients with metastatic AFH who demonstrated a sustained response to chemotherapy; including one who achieved complete remission with cryoablation. These cases reinforce the potential value of chemotherapy in some patients with unresectable metastatic AFH and provide the first case in the literature of cryoablation in AFH.

Paraneoplastic syndrome due to angiomatoid fibrous histiocytoma: a known presentation of an uncommon diagnosis in a rare site and age

A woman in her 70s presented with a small subcutaneous retrosacrococcygeal mass and a history of elevated erythrocyte sedimentation rate present for several years. It was misdiagnosed as an inflammatory process of unclear origin. She underwent further investigation with the appearance of weight loss and weakness. A sacrococcygeal mass was noted on CT scan. A core needle biopsy was inconclusive for chordoma versus myoepithelioma. Wide surgical resection of the tumour including the coccygeal bone was performed. Following surgery, all the systemic symptoms resolved with normalisation of inflammatory markers. The pathological examination showed a relatively circumscribed multinodular myxoid tumour with lymphatic tissue cuff. Pan-sarcoma fusion analysis detected an EWSR1 (Exon7)-CREB1 (Exon7) fusion gene. The lesion was diagnosed as angiomatoid fibrous histiocytoma with paraneoplastic syndrome presentation of several years' duration.

Molecular Mechanisms of Kaposi Sarcoma Development

Simple Summary

There are at least four forms of Kaposi’s sarcoma (KS) with the ‘HIV’-related form being the most aggressive and can involve mucosae or visceral organs. Kaposi’s sarcoma-associated herpes virus (KSHV) is the underlying cause of this disease. It can infect endothelial and/or mesenchymal cells and establish a latent phase in host cells in which latency proteins and various non-coding RNAs (ncRNAs) play a complex role in proliferation and angiogenesis. It also undergoes periods of sporadic lytic reactivation that are key for KS progression. Complex interactions with the microenvironment with production of inflammatory cytokines and paracrine signaling is a standout feature of KS development and maintenance. KSHV impairs the immune response by various mechanisms such as the degradation of a variety of proteins involved in immune response or binding to cellular chemokines. Treatment options include classical chemotherapy, but other novel therapies are being investigated.

Abstract

Kaposi’s sarcoma (KS) is a heterogeneous angioproliferative tumor that generally arises in the skin. At least four forms of this disease have been described, with the ‘HIV’-related form being the most aggressive and can involve mucosae or visceral organs. Three quarters of KS cases occur in sub-Saharan Africa (SSA) as geographic variation is explained by the disparate prevalence of KS-associated herpes virus (KSHV), which is the underlying cause of this disease. It can infect endothelial and/or mesenchymal cells that consequently transdifferentiate to an intermediate state. KSHV establishes a latent phase in host cells in which latency proteins and various non-coding RNAs (ncRNAs) play a complex role in proliferation and angiogenesis. It also undergoes periods of sporadic lytic reactivation triggered by various biological signals in which lytic stage proteins modulate host cell signaling pathways and are key in KS progression. Complex interactions with the microenvironment with production of inflammatory cytokines with paracrine signaling is a standout feature of KS development and maintenance. KSHV impairs the immune response by various mechanisms such as the degradation of a variety of proteins involved in immune response or binding to cellular chemokines. Treatment options include classical chemotherapy, but other novel therapies are being investigated.

Tocilizumab Controls Paraneoplastic Inflammatory Syndrome but Does Not Suppress Tumor Growth of Angiomatoid Fibrous Histiocytoma

Angiomatoid fibrous histiocytoma (AFH) is a rare soft tissue tumor that rarely metastasizes but lacks effective systemic therapy once it propagates. In some reports, high interleukin-6 (IL-6) production promotes tumor growth by autocrine stimulation and tocilizumab, an IL-6 receptor antagonist, can control AFH growth. Here, we present a case report on a patient with local recurrence and distant lymph node metastasis of AFH treated with tocilizumab. As a result, the inhibition of the IL-6 signaling pathway controlled paraneoplastic inflammatory syndrome (PIS); however, the local recurrent tumor progressed. This case implied that IL-6 is not necessarily the cause of tumor growth in AFH. Therefore, physicians should bear in mind that watchful observation is needed whether tocilizumab can control tumor progression despite the amelioration of PIS associated with the attenuated effect of IL-6 on AFH.