Working Diagnosis:
Right knee ruptured epidermal inclusion cyst with brisk foreign body giant cell reaction
Treatment:
The patient underwent a right knee mass excision performed by an orthopedic surgeon.
Outcome:
At the two week postoperative mark, the patient reported right knee tightness, incision hypersensitivity, and postoperative vertigo.
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<br>At three months, the patient reported that the vertigo had resolved independently and returned to a healthy state. The patient did not experience any complications and has since happily returned to the pickleball courts.
Author's Comments:
Epidermal inclusion cysts are the most common benign cutaneous cysts that normally manifest in the upper extremity. Manifestation in the lower extremity is considered a rare pathology, with only four cases investigated since 2004. The current study provides another perspective to elucidate this rare pathology.
Editor's Comments:
When evaluating knee complaints, remember that just because a concern is next to a joint, that it doesn't necessary mean it's actually related to the joint. This case reminds us that sometimes, a mass near a joint is only skin deep.
References:
1. Bashaireh KM, Audat ZA, Jahmani RA, Aleshawi AJ, Al Sbihi AF. Epidermal inclusion cyst of the knee. Eur J Orthop Surg Traumatol. 2019 Aug;29(6):1355-1358. doi: 10.1007/s00590-019-02432-4. Epub 2019 Apr 9. PMID: 30968204.
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<br>2. Mayo M, Werner J, Joshi B, Abramovici L, Strauss EJ. An epidermal inclusion cyst mimicking chronic prepatellar bursitis: a case report. J Knee Surg. 2013 Dec;26 Suppl 1:S103-6. doi: 10.1055/s-0032-1324806. Epub 2012 Sep 21. PMID: 23288748.
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