Question: 20210024




#1:   Primary site


Source 1:   WHO Class Female Genital Organs
Notes:   4th edition
Source 2:  


Primary Site--Vulva:  What is the primary site of patient with an excision of a left vulvar cystic mass showing focal mammary-type ductal carcinoma in situ (DCIS) on 11/06/2020?  See Discussion.


Final Pathologic Diagnosis: 

Vulvar cyst, excision:  Focal mammary-type ductal carcinoma in situ, intermediate grade, arising within cystically dilated duct (See Comment)

Size of DCIS:  0.7 CM.

Margins: Negative.

Sections demonstrate a cystically dilated duct. Focally, at the periphery of the duct, there is a neoplastic monomorphic proliferation of ductal cells with intermediate grade nuclei. No associated necrosis is identified. Immunostains for GATA-3 and estrogen receptor are strongly positive within the neoplastic cells, supporting origin from mammary-like epithelium. Immunostain for p63 demonstrates preservation of a basal layer around the dilated duct, including the region involved by DCIS. Immunostain for cytokeratin 5/6 shows loss of expression within the DCIS. No stromal invasion is identified. The cyst appears to be completely excised.

12/01/2020 post op visit with surgeon:
Ductal carcinoma in situ (DCIS) of the left vulva in an excised cystic lesion.
PLAN: I reviewed the pathologic findings from the excision of the left vulvar cyst. This appears to be a cystic lesion in the mammary line with focal DCIS. It was excised completely with negative margins. It would not warrant any additional treatment except expectant management.


Code the primary site to vulva. Use text fields to record the details.

According to the WHO classification, several types of primary vulvar mammary-like carcinoma have been reported. It is rare and is thought to arise from specialized anogenital mammary-like glands within the vulva. It does not arise from ectopic breast tissue and is does not represent metastatic breast carcinoma.


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