THIS ARTICLE HAS BEEN RETRACTED CD34-reactive tumors of the skin. An updated review of an ever-growing list of lesions

Radiation-induced myofibroblastoma within the nasal sinus requiring maxillectomy and ethmoidectomy: A case report and literature review

We report a case of radiation-induced myofibroblastoma of the right nasal cavity in a patient with a remote history of radiotherapy for pediatric retinoblastoma. The patient required maxillectomy and ethmoidectomy. To our knowledge, a rare number of cases have been reported in this location.

Cutaneous solitary fibrous tumor: Report of three cases with review of histopathological mimics

Solitary fibrous tumor (SFT) is a relatively uncommon spindle cell mesenchymal neoplasm that is most often based on the pleura but may rarely arise in extrapleural locations, including the skin. Herein, we describe three cases of cutaneous SFTs. SFT is characterized by epithelioid and spindle cells arranged in random patterns with focal prominent stromal collagen and pericytomatous vessels. Immunohistochemical evaluation is required for definitive distinction of SFT from other benign and malignant cutaneous spindle cell neoplasms. Although aggressive biologic behavior is uncommon, accurate diagnosis of it is required for prognostication and counseling. CD34, bcl-2, and CD99 stains are positive in SFT, but not specific. STAT6 is the most sensitive and specific immunohistochemical marker to confirm diagnosis of SFT.

Cutaneous and Superficial Soft Tissue CD34+ Spindle Cell Proliferation

CONTEXT

- Cutaneous and superficial soft tissue spindle cell proliferations with CD34 expression represent a unique heterogeneous group of lesions. They can pose diagnostic challenges for unaware pathologists in their daily practice.

OBJECTIVE

- To review selected entities of CD34⁺ spindle cell proliferations in the skin and superficial soft tissue. The effective diagnostic approaches using clinical, histopathologic, and immunophenotypical findings are discussed within a broad spectrum of differential diagnosis.

DATA SOURCES

- All information used in the article is obtained from published literature by PubMed search and Internet-based search engines. The authors' collective experience and real-life examples are also used.

CONCLUSIONS

- Spindle cell proliferations with CD34 positivity can be worked up to a definitive diagnosis by using clinical, histopathologic, and immunophenotypical findings. Familiarity with these entities helps pathologists make the accurate diagnosis.

Pleomorphic hyalinizing angiectatic tumor arising in the thigh: A case report

Pleomorphic hyalinizing angiectatic tumors (PHATs) are rare non-metastasizing tumors of uncertain lineage. The current study presents a case of PHAT arising in the thigh of a 68-year-old female and examines the clinicopathological characteristics of the tumor. Magnetic resonance imaging (MRI) revealed an intramuscular mass located in the adductor longus. The tumor was surrounded by lipomatous tumor. Wide resectioning was performed for the internal tumor, whereas intralesional resectioning was performed for the external tumor. Histopathologically, the internal lesion was diagnosed as a PHAT and the external lesion was diagnosed as an hemosiderotic fibrolipomatous lesion (HFLL). No recurrence or metastases were identified during the 6-year follow-up period. As the adipose tissue surrounding the PHAT resembled a HFLL, therefore, the association between ‘early PHAT’ and HFLL is discussed. Although PHATs may represent low-grade sarcomas, HFLLs may be benign tumors.

Proximal-type epithelioid sarcoma -- case report

Epithelioid sarcoma, first described by Enzinger in 1970, is a rare soft-tissue sarcoma typically presenting as a subcutaneous or deep dermal mass in distal portions of the extremities of adolescents and young adults. In 1997, Guillou et al. described a different type of epithelioid sarcoma, called proximal-type epithelioid sarcoma, which is found mostly in the pelvic and perineal regions and genital tracts of young to middle-aged adults. It is characterized by a proliferation of epithelioid-like cells with rhabdoid features and the absence of a granuloma-like pattern. In this paper we present a case of proximal-type epithelioid sarcoma with an aggressive clinical course, including distant metastasis and death nine months after diagnosis.

Spindle cell lipoma of the tongue: A case report of unusual occurrence

Spindle cell lipoma (SCL) is a benign lipomatous tumor predominantly occurring at the posterior neck and shoulder area. Face, forehead, scalp, cheek, perioral area, and upper arm are less common sites. In oral cavity, it is a relatively uncommon neoplasm, particularly in tongue, which is relatively devoid of fat cells. We present a case report of SCL located on the left lateral border of the tongue in a 64-year-old Caucasian female patient with diabetes mellitus type 2 and arterial hypertension.

Opposing roles for CD34 in B16 melanoma tumor growth alter early stage vasculature and late stage immune cell infiltration

Tumor growth and metastasis are determined by the complex interplay of factors, including those intrinsic to tumor cells and extrinsic factors associated with the tumor microenvironment. Our previous work demonstrated key roles for CD34 in the maintenance of vascular integrity and eosinophil and mast cell homing. Since both of these functions affect tumor development, we characterized the effect of CD34 ablation on tumor growth using the B16F1 melanoma model. Intriguingly, we found that CD34 plays a biphasic role in tumor progression. In early growth, both subcutaneous-injected tumors and intravenous-injected lung metastases grew more slowly in Cd34^−/− mice. This correlated with abnormal vessel morphology and increased vascular permeability in these mice. Bone marrow transplantation experiments confirmed that this reflects a non-hematopoietic function of CD34. At later stages, subcutaneous tumor growth was accelerated in Cd34^−/− mice and surpassed growth in wildtype mice. Bone marrow chimera experiments demonstrated this difference was due to a hematopoietic function for CD34 and, correspondingly we found reduced intra-tumor mast cell numbers in Cd34^−/− mice. In aggregate, our analysis reveals a novel role for CD34 in both early and late tumor growth and provides novel insights into the role of the tumor microenvironment in tumor progression.

Pleomorphic hyalinizing angiectatic tumor of soft parts involving the upper limb

Pleomorphic hyalinizing angiectatic tumor (PHAT) of soft parts is a low grade, rare, soft tissue tumor which commonly occurs on the lower extremities of adults of either sex, though lesions in other anatomic locations have been described. We present a case of a 65-year-old female patient who presented with a left forearm swelling and underwent a wide local excision. Histopathology revealed it to be a PHAT.

Immunohistochemical analysis of CXCR4 expression in fibrohistiocytic tumors

Functional chemokine receptors are expressed in many malignant tumors. These receptors promote tumor growth and metastasis in response to endogenous chemokines. We analyzed the expression of CXCR4, CCR6 and CCR7 in fibrohistiocytic tumors, including dermatofibrosarcoma protuberance (DFSP), malignant fibrous histiocytoma (MFH), dermatofibroma (DF) using immunohistochemistry. We also investigated the relationship between CXCR4 and CD34, the latter of which is an immunohistochemical marker for DFSP. We observed a higher expression of CXCR4 in DFSP and MFH as compared with DF. Interestingly, a significantly higher expression of CXCR4 was detected in relapsed DFSP than in non-relapsed DFSP, but no significant differences were detected between non-relapsed DFSP and DFSP with CD34 immunostaining. Moreover, MFH had strong immunoreactivity for CXCR4, CCR6 and CCR7. These findings suggest that the assessment of CXCR4 immunoreactivity in fibrohistiocytic tumors is a useful tool for predicting tumor aggressiveness.