Skin, Spindle cell melanoma [LMP23494]

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Image Details
Diagnostic Modality: 
Whole Slide Image
Disease Category: 
Neoplasia
Diagnosis: 
Spindle cell melanoma
Species: 
Human
Organ System: 
Skin
Gender: 
Female
Age: 
70 years
Diagnosis Code: 
ICD-10: C43 | ICD-O: 8772/3
Slide Contributor Information
Hosseini, N., Mete, O.

Keywords

melanoma, spindle cell, desmoplastic, neurotropic

Clinical History

Scalp lesion.

Clinical Discussion

Melanoma is a malignant neoplasm derived from pigment-producing cells called melanocytes. Skin is the most common site of involvement, but mucosal surfaces such as the oronasal cavity, eye, vagina, or gastrointestinal mucosa can also be involved. Most spindle cell melanomas are amelanotic or pauci-melanotic and may have scattered collections of lymphocytes and plasma cells. They usually infiltrate deeply (Breslow thickness >4.0mm).

This section demonstrates a spindle cell lesion in the dermis with disruption of the epidermis. There are strands of spindle cells surrounded by collagen bundles and scattered collections of lymphocytes.

Spindle cell melanoma comprises a spectrum of tumours. Those with significant fibrous stroma are called “desmoplastic melanoma” and those with intraneural/perineural invasion are referred to as “neurotropic melanoma”. S100 has a limited value in spindle cell/desmoplastic melanomas. Half of the spindle cell melanomas are positive for HMB45, but pure desmoplastic melanomas are negative for HMB45.

It is important to differentiate spindle cell melanoma from sarcoma, sarcomatoid carcinoma or atypical fibroxanthoma.