Skin nonmelanocytic tumor
Fibrous, fibrohistiocytic and myofibroblastic neoplasms
Pleomorphic dermal sarcoma
Author: Anthony Martinez, M.D.
Editor-in-Chief: Debra L. Zynger, M.D.
Last author update: 7 November 2019
Last staff update: 31 March 2023
Copyright: 2019-2023, PathologyOutlines.com, Inc.
PubMed Search: Pleomorphic dermal sarcoma
Table of Contents
Definition / general | Essential features | Terminology | ICD coding | Epidemiology | Sites | Etiology | Clinical features | Diagnosis | Prognostic factors | Case reports | Treatment | Clinical images | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Molecular / cytogenetics description | Sample pathology report | Differential diagnosis | Additional references | Board review style question #1 | Board review style answer #1 | Board review style question #2 | Board review style answer #2Cite this page: Martinez A. Pleomorphic dermal sarcoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/skintumornonmelanocyticpleomorphicdermalsarcoma.html. Accessed June 7th, 2023.
Definition / general
- An undifferentiated pleomorphic tumor with overlapping features of atypical fibroxanthoma but a higher rate of local recurrence and metastasis
Essential features
- Undifferentiated pleomorphic tumor involving the dermis that histologically looks like an atypical fibroxanthoma and has any of the following:
- Size > 2 cm
- Shows extensive involvement of deeper tissue (subcutis, skeletal muscle, fascia)
- Necrosis
- Perineural
- Lymphovascular invasion
Terminology
- Pleomorphic dermal sarcoma (PDS)
- Undifferentiated pleomorphic sarcoma of the skin
- Superficial malignant fibrous histiocytoma (terminology no longer used)
ICD coding
- ICD-10: C49.9 - malignant neoplasm of connective and soft tissue, unspecified
Epidemiology
- Predominantly affects elderly patients on sun damaged skin
- Median decade: ninth (Am J Surg Pathol 2012;36:1317)
- M > F (Cancer 1973;31:1541)
Sites
- Head and neck, predilection for scalp
Etiology
- Ultraviolet radiation induced damage and immunosuppression
Clinical features
- Rapidly growing nodules or plaques, often > 2 cm (Am J Surg Pathol 2012;36:1317)
- Ulceration can be present
Diagnosis
- Dependent on clinical and tissue pathologic correlation
Prognostic factors
- Local recurrence rate of 20 - 30% (Am J Surg Pathol 2012;36:1317, J Cutan Pathol 2016;43:101)
- Median time to recurrence: 10 months (Am J Surg Pathol 2012;36:1317)
- Metastatic rate of 10 - 20% (Am J Surg Pathol 2012;36:1317, J Cutan Pathol 2016;43:101)
- Presence of metastatic disease associated with increased mortality
Case reports
- 58 year old woman with a multifocal tumor arising in areas of alpha-1-antitrypsin deficiency panniculitis and a history of lung transplantation (J Med Case Rep 2019;13:169)
- 69 year old man with an enlarging, asymptomatic nodule on his forehead (An Bras Dermatol 2018;93:307)
- 77 year old man with a large nodular scalp lesion (Cureus 2018;10:e2979)
- 91 year old woman with a mass on the lateral aspect of the right upper eyelid (Ann Dermatol 2016;28:632)
Treatment
- Surgery is gold standard
- Adjuvant radiation employed in setting of metastatic or locally recurrent, unresectable disease (Curr Treat Options Oncol 2017;18:50)
Clinical images
Images hosted on other servers:
Rapidly growing scalp mass
Well circumscribed, erythematous papule
Solitary protuberant mass on upper eyelid
Microscopic (histologic) description
- Dermal based lesion composed of pleomorphic cells with vesicular nuclei and prominent nucleoli (Cancer 1973;31:1541)
- Cells can be spindled or epithelioid, often with admixed multinucleated giant cells
- Cells can be arranged in sheets and fascicles
- Necrosis often present
- Perineural and lymphovascular invasion can be seen
- Infiltration into subcutis, skeletal muscle or fascia
- Additional findings include myxoid change, pseudoangiomatous growth and storiform growth (Am J Surg Pathol 2012;36:1317)
Microscopic (histologic) images
Contributed by Anthony Martinez, M.D.
Dermal based neoplasm
Cytologic atypia
Necrosis
Extensive subcutis involvement
Sheet-like growth
HMWK
Positive stains
- CD10
- Actin - alpha smooth muscle (usually nonspecific staining)
- References: J Cutan Pathol 2018;45:880, Am J Surg Pathol 2012;36:1317
Negative stains
- Both high and low weight cytokeratins: AE1 / AE3, 34betaE12 / HMWCK / high molecular weight, CK5 / 6
- p40
- Desmin, S100 protein, SOX10, MelanA
- Reference: J Cutan Pathol 2018;45:880
Molecular / cytogenetics description
- 50 - 70% NOTCH1 / 2 and FAT1 mutations (Mod Pathol 2018;31:418)
- TERT promoter mutations in > 70% (Mod Pathol 2014;27:502)
- TP53 mutations in > 80% (Mod Pathol 2018;31:418)
Sample pathology report
- Skin, scalp, excision:
- Pleomorphic dermal sarcoma
- Tumor measures 3.5 cm in greatest dimension and extensively involves the subcutaneous tissue
- Necrosis is present: 30%
- Lymphovascular invasion is not identified
- Perineural invasion is not identified
- Margins are negative
Differential diagnosis
- Atypical fibroxanthoma:
- May be identical histologically, especially if only a superficial shave biopsy is performed
- Tends to have a well circumscribed and pushing border with less infiltration into deep soft tissue
- Should not have perineural invasion
- Should not have lymphovascular invasion
- More than a minute focus of necrosis should raise suspicion
- Cutaneous leiomyosarcoma:
- Will also be dermal based
- Composed of intersecting fascicles of spindled cells with eosinophilic cytoplasm
- Intersecting fascicles will often create halo effect around nuclei cut on cross section
- Should express multiple smooth muscle markers such as desmin, caldesmon, actin - alpha smooth muscle
- Actin - alpha smooth muscle expression by itself is not enough to call leiomyosarcoma
- Sarcomatoid squamous cell carcinoma:
- May have overlying dysplasia of epithelium
- Should express cytokeratins and p63 / p40
- Cellular neurothekeoma:
- Also occurs in the head and neck region
- Occurs in young females instead of elderly males
- Microscopically composed of sheets and nest of spindled and epithelioid cells with gray cytoplasm with cytologic atypia and mitoses
- Usually shows variable expression of CD10, microphthalmia transcription factor (MITF) and actin - alpha smooth muscle
- For board testing purposes, NKI-C3+ and S100A6+
Additional references
Board review style question #1
The following image is from a scalp lesion in an 85 year old man. Immunostains for AE1 / AE3, 34betaE12 / HMWCK / high molecular weight, S100, actin - alpha smooth muscle, desmin and ERG are negative. Which is the best diagnosis?
- Atypical fibroxanthoma
- Leiomyosarcoma
- Pleomorphic dermal sarcoma
- Sarcomatoid squamous cell carcinoma
Board review style answer #1
Board review style question #2
An 80 year old man has a dermal based scalp lesion characterized by pleomorphic cells growing in fascicles. The lesion is < 2 cm, well circumscribed and completely confined to the dermis. Immunostains are negative for high and low molecular weight keratins, S100, actin - alpha smooth muscle and desmin. What is the best diagnosis?
- Atypical fibroxanthoma
- Leiomyosarcoma
- Pleomorphic dermal sarcoma
- Sarcomatoid squamous cell carcinoma
Board review style answer #2
