Small cells with scant cytoplasm and small hyperchromatic nuclei; typically at periphery of tumor lobules

image Larger cells with eosinophilic cytoplasm and oval, vesicular nuclei; typically in centers of tumor lobules

• Focal to diffuse duct lumen formation

• Tumor lobules associated with vascularized stroma, hemorrhage may be present

Top Differential Diagnoses

• Cylindroma
image Significant overlap with spiradenoma and may have combined tumors

image Cylindroma has jigsaw puzzle pattern

• Spiradenocarcinoma (malignant spiradenoma)
image Associated with precursor spiradenoma

• Basal cell carcinoma
image Peripheral palisading with tumor-stroma retraction

• Merkel cell carcinoma
image More cytologic atypia and high mitotic rate

image Positive for CK20 and neuroendocrine markers

Spiradenoma at Low Magnification
Low magnification of a spiradenoma shows a dermal-based tumor characterized by irregularly-shaped nodules and smaller lobules image in the dermis.

Spiradenoma With Large Dermal Nodules
Spiradenoma is characterized by circumscribed, cellular basophilic nodules or lobules in the dermis. The tumor lobules often have a surrounding fibrous capsule image.

Spiradenoma With Edematous Stroma
The stroma in this case is edematous and highlights the associated capillary vasculature image.

Spiradenoma at High Magnification
The tumor is composed of a biphasic population of smaller basaloid cells and larger pale cells. Duct lumen formation image is present and may be focal or relatively prominent, as in this case.



• Eccrine spiradenoma


• Benign adnexal tumor composed of nodules of basaloid cells with ductal differentiation

• May have apocrine or eccrine differentiation


Genetic Syndrome

• Familial cases associated with autosomal dominant Brooke-Spiegler syndrome
image a.k.a. familial cylindromatosis or turban tumor syndrome

image Multiple cylindromas, but can also have spiradenomas and trichoepitheliomas



• Age
image Most common in young adults but can present at any age


• Upper 1/2 of body most commonly involved; > 75% present on ventral surface


• Dermal mass/nodular lesion
image Often tender or painful, may have bluish color

image Usually solitary but may be multiple

– Multiple lesions may be part of Brooke-Spiegler syndrome

– Less frequently, may be associated with trichoblastoma and cutaneous lymphadenoma as part of morphological spectrum of Brooke-Spiegler syndrome


• Surgical approaches
image Complete surgical excision is curative


• Benign, but local recurrence may occur; very rare malignant transformation

Apr 24, 2017 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Spiradenoma

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