July 2016 Case of the Month

52 year old woman presents to her gynecologist with a vaginal polyp.  Polyypectomy is peformed.  What is your diagnosis?

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Sections reveal a polypoid lesion with benign squamous epithelial mucosa overlying a pale eosinophilic stromal lesion.

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Scattered muscular vessels are distributed throughout the spindle cell stromal lesion.

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S-100 10X
S-100 10X

Negative.

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Sections reveal a polypoid lesion with benign squamous epithelial mucosa overlying a pale eosinophilic stromal lesion.

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July 2016 Case of the Month

   Answer: Rhabdomyoma

Rhabdomyoma is a rare benign tumor of mature skeletal muscle derivation.  The vagina is the most common location for these tumors to arise in the female genital tract.  This benign tumor may arise in both reproductive age and postmenopausal women.  The lesional "strap cells" observed show features typical of mature skeletal muscle, including large linear cells with multinucleation, nuclei at the periphery of the cytoplasm, and deeply eosinophilic cytoplasm with cross striations.  Desmin positivity and SMA negativity supports skeletal muscle phenotype.  These are benign tumors that are cured by excision, though thorough sampling should be performed to exclude any malignant rhabdomyosarcomatous component.