Detailed analysis of a superficial CD34-positive fibroblastic tumor: A case report and review of the literature

Abstract

Superficial cluster of differentiation (CD)34-positive fibroblastic tumor (SCPFT) is a rare mesenchymal neoplasm of borderline malignancy. It is characterized by a superficial location, marked cellular pleomorphism, an extremely low incidence of mitotic figures, and strong CD34 immunohistochemical positivity. As SCPFT is a recently described neoplasm, its characteristics are yet to be fully elucidated. To the best of our knowledge, no detailed studies regarding the imaging findings and cytogenetic analyses of SCPFTs exist. The present study describes a typical case of an 18-year-old man who developed an SCPFT measuring 87×70×80 mm in the subcutaneous adipose tissue of his right thigh. Computed tomography (CT) revealed a well-marginated tumor without calcification, and the enhancement on CT was weak. The tumor demonstrated abnormal uptake on 2-(18F) fluoro-2-deoxy-D-glucose positron emission tomography (PET), with a maximum standardized uptake value of 2.57. Magnetic resonance imaging (MRI) revealed a clearly defined tumor that exhibited homogeneous low signal intensity on T1-weighted imaging and high signal intensity on T2-weighted imaging, with small lobulated structures. Histopathologically, the tumor was composed of irregular spindle-to-oval-shaped cells with eosinophilic glassy cytoplasm and hyperchromatic, bizarre and pleomorphic nuclei that frequently exhibited intranuclear pseudoinclusions. Immunohistochemically, the tumor cells were diffusely and strongly positive for CD34. The Mindbomb E3 ubiquitin protein ligase 1 labeling index was 8.6%. Ultrastructurally, the tumor cells exhibited irregular or convoluted nuclei with abundant euchromatin-prominent nucleoli. The cytoplasmic organelles consisted of scattered, abundant rough endoplasmic reticulum, mitochondria, lysosomes, ribosomal rosettes and aggregated lipid globules. Of 18 metaphase cells identified, 2 demonstrated translocation between chromosomes 2 and 5 in cytogenetic studies. To the best of our knowledge, this is the first study describing imaging data (CT, MRI and PET-CT) and chromosomal aberrations for SCPFT.

Superficial CD34 positive fibroblastic tumor: report of three cases and review of the literature

“…Median size was 2.7 cm (1.6–5). A few more reported cases had similar clinical presentations with neck or Achilles tendon involvement . Our cases were consistent with the literature.…”

“…Morphologically, SCPFT resembles fibrohistiocytic tumors. After the description of this entity by Carter et al ., 34 similar cases have been reported to date . Our three cases hereby show the characteristic morphological and immunohistochemical features described in the literature, with a few additional unique features.…”

“…first described SCPFT as a new and unique entity, in a series of 18 cases . Thirty‐four cases were reported to date to the best of our knowledge . These tumors, although composed of highly pleomorphic cells, have low mitotic rate and are classified under borderline mesenchymal tumors of soft tissues.…”

Superficial CD34-positive fibroblastic tumor: Report of an extremely rare entity

“…[ 1 ] To date, few cases counting only up to 35, of SCPFT have been reported. [ 2 3 ] This rarity is probably largely due to under-recognition.…”

“…[ 1 ] To date, 35 cases of SCPFT have been described histopathologically and immunohistochemically. [ 2 3 ]…”