Glomus Tumors

Glomus Tumors

Thomas Mentzel, MD

Clinical photograph shows a rare malignant glomus tumor.

Hematoxylin & eosin shows perivascularly arranged myogenic tumor cells that contain uniform round nuclei in a benign glomus tumor.



  • Glomus tumor (GT)


  • Perivascular myogenic mesenchymal neoplasm composed of cells closely resembling smooth muscle cells of normal glomus body



  • Incidence

    • Rare

    • Account for < 2% of soft tissue neoplasms

  • Age

    • Predominantly occur in young adults

    • May occur at any age

  • Gender

    • No sex predilection


  • Distal extremities

  • Often in subungual location

  • Rare in other anatomic locations (visceral organs, bone, mediastinum, nerve)

  • Skin, subcutis

  • Rare in deep soft tissue


  • Typically small, red-blue nodules

  • Painful mass; long history of pain

  • Pain with exposure to cold &/or tactile stimulation

  • Usually solitary lesions

  • Rarely, may be multiple neoplasms

  • Multiple lesions more common in children

Natural History

  • < 10% recur locally

  • Malignant glomus tumors highly aggressive

  • Metastases and death of patients in up to 40% of cases


  • Surgical approaches

    • Complete excision


  • Benign behavior in most cases


General Features

  • Red-blue nodular lesions


Histologic Features

  • Perivascular myoid tumor cells

  • Small, uniform, round tumor cells

  • Centrally placed, sharply punched-out, round nuclei

  • Eosinophilic cytoplasm

  • Each cell surrounded by basal lamina

Predominant Pattern/Injury Type

  • Circumscribed

Predominant Cell/Compartment Type

  • Smooth muscle

Solid Glomus Tumor

  • Most common variant

  • Well-circumscribed nodular neoplasm

  • Contains numerous capillary-sized vessels

  • Nest of tumor cells surrounding capillaries

  • Stroma may show hyalinization

  • Stroma may show myxoid changes

  • Rare degenerative cytologic atypia

  • Rare vascular invasion may be identified

  • Peripheral rim of collagen (fibrous pseudocapsule)

  • May contain numerous hemangiopericytoma-like vessels

  • Rare oncocytic changes

  • Rare epithelioid variant


  • Comprises up to 20% of glomus tumors

  • Most common type in patients with multiple lesions

  • Less well-circumscribed

  • Dilated veins surrounded by clusters of glomus cells

  • Secondary thrombosis may occur


  • Rare subtype

  • Solid glomus tumor or glomangioma with elongated, spindled smooth muscle cells


  • Extremely rare variant

  • Infiltrative growth

  • Multiple nodules of solid glomus tumor

  • Biologically benign lesions

Symplastic Glomus Tumor

  • Cells show prominent degenerative atypia

  • Multinucleated giant cells

  • Enlarged nuclei

  • No increased proliferative activity

  • No tumor necrosis

Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Glomus Tumors

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