Soft tissue
Fibroblastic / myofibroblastic
Superficial CD34+ fibroblastic tumor


Topic Completed: 22 October 2020

Minor changes: 22 October 2020

Copyright: 2019-2020, PathologyOutlines.com, Inc.

PubMed Search: Superficial CD34+ fibroblastic tumor pathology review

Borislav A. Alexiev, M.D.
Page views in 2019: 77
Page views in 2020 to date: 479
Cite this page: Alexiev B. Superficial CD34+ fibroblastic tumor. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/softtissuesuperficialcd34fibro.html. Accessed October 26th, 2020.
Definition / general
  • Superficial CD34+ fibroblastic tumor is a distinctive low grade neoplasm of the skin and subcutis, characterized by a fascicular proliferation of spindled cells with abundant, eosinophilic, granular to glassy cytoplasm, marked nuclear pleomorphism and low mitotic count (Mod Pathol 2014;27:294)
  • Invariably express CD34 and are focally immunoreactive for keratin in close to 70% of cases (Mod Pathol 2014;27:294, Histopathology 2017;70:394)
Essential features
Terminology
  • PRDM10 rearranged soft tissue tumor
ICD coding
  • ICD-0: 8810/1 - superficial CD34+ fibroblastic tumor
  • ICD-11: 2B53.Y - other specified fibroblastic and myofibroblastic tumor, primary site
Epidemiology
Sites
Etiology
  • Unknown at this time
Clinical features
Diagnosis
  • Tissue sampling with microscopic examination is the gold standard for a definitive diagnosis
Radiology description
  • Well marginated tumor without calcification in the subcutaneous adipose tissue on CT / MRI scans (Oncol Lett 2017;14:3395)
  • Tumor demonstrates abnormal uptake on 2-(18F) fluoro-2-deoxy-D-glucose (18F-FDG) (PET) (Oncol Lett 2017;14:3395)
Radiology images

Contributed by Borislav Alexiev, M.D.
CT scan

CT scan

Prognostic factors
Case reports
  • 18 year old man with a painless mass in the medial aspect of his right distal thigh (Oncol Lett 2017;14:3395)
  • 48 year old man presented with a gradually increasing soft tissue mass in his right forearm of 2 years' duration (Indian J Pathol Microbiol 2018;61:421)
  • 48 year old woman presented with a painless, slow growing, brown nodule on the left thigh (J Dermatol 2016;43:934)
  • 50 year old woman presented with a four month history of a slowly enlarging, firm, painless mass at the medial aspect of her right knee below unremarkable overlying skin (Diagn Cytopathol 2016;44:926)
  • 55 year old woman with a slowly enlarging mass on the ventral antebrachium (Dermatol Surg 2017;43:1489)
  • 75 year old woman with no significant medical history presented with a firm erythematous asymptomatic nodule on the left posterior thigh (Dermatol Surg 2018;44:313)
Clinical images

Images hosted on other servers:

Thigh mass

Gross description
Gross images

Contributed by Borislav Alexiev, M.D.
Soft tissue mass

Soft tissue mass

Frozen section description
Microscopic (histologic) description
Microscopic (histologic) images

Contributed by Borislav Alexiev, M.D.
Spindle cells

Spindle cells

Chronic inflammation

Chronic inflammation

Fascicular growth pattern

Fascicular growth pattern

Pleomorphic nuclei

Pleomorphic nuclei

CD34

CD34

AE1 / AE3

AE1 / AE3

Cytology description
  • Cellular specimen composed of mostly spindle cells, arranged singly and in clusters in the background of fragments of collagenized stroma (Diagn Cytopathol 2016;44:926)
  • Numerous spindle cells with tapered nuclei and elongated cytoplasmic processes admixed with scattered large pleomorphic cells with enlarged plump nuclei, irregular nuclear contours and bizarre shapes (Diagn Cytopathol 2016;44:926)
Electron microscopy description
Electron microscopy images

Images hosted on other servers:

Lipid globules

Molecular / cytogenetics description
Molecular / cytogenetics images

Images hosted on other servers:

t(2;5)

Sample pathology report
  • Thigh, mass, excision:
    • Superficial CD34+ fibroblastic tumor (see comment)
    • Comment: Microscopic sections show a circumscribed tumor in the dermis and subcutaneous fat composed of spindle cells containing moderate to abundant glassy eosinophilic cytoplasm, vesicular nuclei with distinct nucleoli and intranuclear pseudoinclusions, along with interspersed pleomorphic giant cells. Tumor cells are arranged in fascicular or sheet-like patterns. Neither necrosis nor mitotic activity is identified. Also present is a chronic inflammatory infiltrate of lymphocytes, plasma cells, mast cells and eosinophils.
    • Immunohistochemically, neoplastic cells show diffuse and strong expression of CD34 and focal staining of cytokeratin while are negative for myogenin, S100 and STAT6. INI1 is preserved. Fluorescence in situ hybridization studies for TGFBR3 and MGEA5 are negative.
    • This constellation of morphological, immunohistochemical and molecular features strongly supports the diagnosis of superficial CD34+ fibroblastic tumor. It is a distinctive low grade neoplasm of the skin and subcutis. The majority of patients have no disease recurrence.
Differential diagnosis
Board review style question #1

A 29 year old man presented with a left thigh mass. Hematoxylin eosin stains demonstrate a circumscribed tumor in the dermis and subcutaneous fat composed of spindle cells containing moderate to abundant glassy eosinophilic cytoplasm, vesicular nuclei with distinct nucleoli and intranuclear pseudoinclusions, along with interspersed pleomorphic giant cells. Tumor cells are arranged in fascicular or sheet-like patterns. Neither necrosis nor mitotic activity is identified. Immunohistochemical stains for CD34 and keratin AE1 / AE3 are positive in tumor cells while all of the following are negative: MUC4, SMA, Desmin, S100 and STAT6. INI1 is retained. Which of the following is most likely the correct diagnosis?

  1. Epithelioid sarcoma
  2. Low grade fibromyxoid sarcoma
  3. Myxofibrosarcoma
  4. Solitary fibrous tumor
  5. Superficial CD34+ fibroblastic tumor
Board review answer #1
E. Superficial CD34+ fibroblastic tumor

Comment Here

Reference: Superficial CD34+ fibroblastic tumor
Board review style question #2
Which of the following is true about superficial CD34+ fibroblastic tumor?

  1. High recurrence rate
  2. INI1 / SMARCB1 expression is lost
  3. Tumor is negative for keratin
  4. Tumor is positive for TGFBR3 / MGEA5 translocation
  5. Tumor is positive for PRDM10
Board review answer #2
E. Tumor is positive for PRDM10

Comment Here

Reference: Superficial CD34+ fibroblastic tumor
Back to top
Image 01 Image 02