SKIN 
 

March 2022     Volume 6 Issue 2 
 

(c) 2022 THE AUTHORS. Published by the National Society for Cutaneous Medicine. 170 

SHORT COMMUNICATIONS 
 

 

Desmoplastic Malignant Melanoma Clinically Presenting as a 
“Cyst” 
 

Haley D. Heibel, MD1, Robin Burger, MD2, and Clay J. Cockerell, MD, MBA3,4 

 
1 Department of Dermatology, Northwestern University Feinberg School of Medicine, Chicago, IL 
2 Advanced Dermatology and Cosmetic Surgery, Delray Beach, FL 
3 Cockerell Dermatopathology, Dallas, TX 
4  Departments of Dermatology and Pathology, UT Southwestern Medical Center, Dallas, TX 
 

 
 

We recently reviewed the histopathology of 
an excision of a lesion that had been 
clinically diagnosed and managed as a cyst.  
The lesion was present on the back of a 58-
year-old female (Figure 1) and had been 
injected with intralesional steroids for over 
one year with minimal improvement, which 
led to a biopsy.  
 

 
Figure 1. Desmoplastic melanoma.  This lesion 
presented clinically as a “cyst.” 

 
Histopathologic analysis of the excision 
revealed an atypical proliferation of 
pleomorphic spindle cells in a desmoplastic 
stroma with lymphoid aggregates in the 

dermis extending near to the subcutaneous 
fat (Figure 2).  Immunohistochemical stains 
were positive for SOX-10 and negative for 
CD34 and CD68 confirming the diagnosis of 
desmoplastic malignant melanoma (DMM). 
 

 
Figure 2. Histology of desmoplastic melanoma (H&E, 
40x) demonstrating an atypical proliferation of 
pleomorphic spindle cells in a desmoplastic stroma 
with lymphoid aggregates in the dermis extending to 
near the subcutaneous fat. 

 
DMM often eludes clinical diagnosis as it 
usually does not have characteristic features 
of melanoma.  Many lesions are not 
pigmented and may present as an indurated 
plaque or nodule often on the head and 
neck region.1-3  They may clinically resemble 



SKIN 
 

March 2022     Volume 6 Issue 2 
 

(c) 2022 THE AUTHORS. Published by the National Society for Cutaneous Medicine. 171 

a scar, dermatofibroma, neurofibroma, 
fibromatosis, basal cell carcinoma, or 
squamous cell carcinoma, which may lead 
to misdiagnosis and a delay in appropriate 
treatment.2,4  Comprising less than 2-4% of 
primary cutaneous melanomas, the rarity 
and lack of characteristic morphology may 
impede the correct clinical diagnosis of 
DMM.2,4 
 
Over the last number of years, we have 
histologically diagnosed 7 cases of DMM 
that were submitted by well-trained and 
experienced dermatologists with a clinical 
impression of “cyst.”  While a number of 
different entities, including serious 
malignancies such as metastatic neoplasms, 
may be thought to be cysts clinically, DMM 
is not a lesion that is characteristically 
thought to present as a cyst.  Thus, this is a 
cautionary note to alert dermatologists that 
DMM should be considered in the clinical 
differential diagnosis of a cyst in some 
cases.  When a lesion that is thought to be a 
cyst has an unusual morphology or does not 
respond to therapy in a reasonable time, a 
biopsy should be performed in a fashion that 
will allow for an accurate diagnosis to be 
rendered.  An incisional or excisional biopsy 
may be preferred, given that DMM may be 
difficult to diagnose histologically as well.  
Delay in diagnosis can lead to adverse 
patient outcomes and medicolegal liability.  
The knowledge that DMM may present 
clinically as a “cyst” can lessen the likelihood 
of such delay and avoid these 
consequences.2 
 
Conflict of Interest Disclosures: None 
 
Funding: None 
 
Corresponding Author: 
Haley D. Heibel, MD 
875 North Michigan Avenue 
Suite 1525 
Chicago, IL 60611 
Phone: (312) 227-6817 

Fax: (312) 227-9402 
Email: haley.heibel@northwestern.edu  

 
 
References: 
1. Barnhill RL, Gupta K. Unusual variants of 

malignant melanoma. Clin Dermatol. 
2009;27(6):564-587. 

2. Cabrera R, Recule F. Unusual clinical 
presentations of malignant melanoma: A review of 
clinical and histologic features with special 
emphasis on dermatoscopic findings. Am J Clin 
Dermatol. 2018;19 (Suppl 1):15-23. 

3. Rongioletti F, Smoller BR. Unusual histological 
variants of cutaneous malignant melanoma with 
some clinical and possible prognostic correlations. 
J Cutan Pathol. 2005;32(9):589-603. 

4. Chen LL, Jaimes N, Barker CA, Busam KJ, 
Marghoob AA. Desmoplastic melanoma: A review. 
J Am Acad Dermatol. 2013;68(5):825-833.