Image-Guided Core-Needle Biopsy for the Diagnosis of Cutaneous Calciphylaxis

Mask-Bull L, Lee MP, Wang A.

PMID: 31116352 Full Text at JAMA Dermatology

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Itunu Owoyemi discusses use of a needle core biopsy to diagnose CUA in a dialysis patients. What are the implications of bringing this technique to this difficult to diagnose disease?

Pathology of Calcific Uremic Arteriolopathy

This week is a joint #DermJC and #NephJC. We will discuss two articles - here is the summary of the larger case series, from Vandana Niyyar.

Summary

Calciphylaxis is a serious a debilitating disorder which manifests as skin ischemia and necrosis. Histologically, there is calcification of arterioles in the dermis and subcutaneous adipose tissue. The term calcemic uremic arteriolopathy (CUA) is more descriptive in end-stage kidney disease (ESKD) patients as calciphylaxis can also occur in patients without ESKD. It is associated with excruciating pain, diminished quality of life and poor prognosis. There are typical and atypical manifestations of CUA. Malodorous ulcers with black eschars occur late and are classical presentations. However, atypical features such as painful nodules, plaques, livedo or purpura pose a diagnostic challenge. Sometimes, when CUA is suspected, dermatologists are consulted to assist with diagnosis. Skin biopsies are traditionally done usually as a punch or incisional wedge biopsy; a procedure which can be high risk procedures with low diagnostic yield. Biopsy complications include bleeding, delayed wound healing, worsening ulceration, and worsening pain.

In this case report, a percutaneous image guided core needle-biopsy was used to obtain a specimen from a patient undergoing hemodialysis with a suspicious nodule thought to be CUA. The nodule had no apparent skin changes on physical examination. Several specimens from the patient’s thigh was obtained and evaluated to have multiple foci of vascular calcifications.

The authors highlight that the advantages of percutaneous image guided core- needle biopsy in non-dermatologic settings as an alternative to surgical biopsies in the diagnosis of cancers. Many studies report 100% correlation with surgical results and false negative as low as 0-2%. It is a well-tolerated quick and safe procedure with a lower rate of infection, necrosis or induction of new skin lesions compared to punch or incisional biopsies. They also mention the diagnostic yield of the image guided core needle biopsy to be up to 50- fold higher than a punch biopsy.

Although this case report mentions the relative convenience of the procedure because of multiple specialists in inpatient setting, it does not mention feasibility in the outpatient setting, cost, and other logistics.

As most dialysis patients are evaluated on an outpatient basis, lack of these information or availability of outpatient services may lead to delayed diagnosis of atypical or early onset CUA for which percutaneous image guided core-needle biopsy technique is recommended. Probably a quality improvement initiative involving a multidisciplinary team of specialist could tackle these issues with establishing the effectiveness of this procedure.

Summary by Itunu Owoyemi, MD,

Onco-nephrology Fellow, Mayo Clinic
NSMC Intern, Class of 2019