#dermpathJC June 2018 summary:

#dermpathJC June 2018:

Thursday, June 28th, 9pm EST

Article discussed: The pathological spectrum and clinical correlation of pigmented purpuric dermatosis – A retrospective review of 107 cases

Authors: Yen-Kai Huang, Cheng-Kuan Lin, Yu-Hung Wu

Temporary open access available at https://onlinelibrary.wiley.com/doi/abs/10.1111/cup.13118

Summary author: Andrea Primiani Moy, MD (@aprimi)

Journal Club Summary:

This month’s journal club article reviewed the clinical and pathologic features of the variants of pigmented purpuric dermatosis (PPD). PPD is a group of skin diseases characterized by the petechiae/purpura with increased pigmentation on the skin of the lower extremities. The clinical variants can be summarized as follows (with Schamberg’s being the most common):

Screen Shot 2018-07-07 at 10.06.01 AM

Interestingly, PPD has been associated with diabetes, autoimmune disease, and hypersensitivity to medications. Granulomatous PPD has been associated with hyperlipidemia.

The authors in this article reviewed 107 cases diagnosed pathologically with PPD over the course of nine years at a tertiary referral centers. Clinical photos and pathology slides were reviewed to ensure an accurate clinicopathologic diagnosis. The authors reviewed the pathological patterns present. Clinical data was also reviewed, and follow-up at one month post biopsy was collected.

Clinical features of the cases studied were discussed. Pigmented purpuric dermatoses – about equivalent male to female ratio, lower extremities involved most frequently (96.3%) and lesions bilateral in 79.4% (Huang et al’s findings).

The histologic patterns seen in biopsy specimens are shown in Figure 1. Spongiotic, Interface, Lichenoid, Perivascular and Granulomatous. Note that the lichenoid and perivascular patterns were most common.

fig 1

Also, epidermal changes were common, as demonstrated in this figure:

fig 2

It was noted that lymphocyte exocytosis may mimic mycosis fungoides (MF) in these biopsies. While no patients in this study were diagnosed with MF at one year following the biopsy, an interesting point and discussion was raised – that they either may declare themselves at a later time or a good handful of patient with atypical lymphocytic proliferation never even meet criteria for Stage IA Mycosis Fungoides.

Based on their statistical analysis, the authors reported that the perivascular pattern was typically seen with Schamberg disease, the lichenoid pattern was seen in lichen aureus or Schamberg disease, the spongiotic pattern was seen with an eczematoid-like purpura, and the interface and granulomatous patterns could appear as any of the clinical variants. Thus, making a clinical diganosis based on histologic features is difficult. However, in contrast, some clinical variants had a predictable pathologic findings – lichen aureus usually shows a lichenoid pattern; Schamberg disease usually showed a perivascular pattern, and a spongiotic pattern was often seen in an eczematoid-like purpura.

The authors also correlated pathologic features with comorbid conditions. The interface pattern was associated with a higher rate of autoimmune disease and gout. All patterns were associated with similar rates of hypertension, hyperlipidemia, and diabetes.

The clinicopathologic features were nicely summarized in this table:

Screen Shot 2018-07-07 at 10.17.49 AM

Given the variation in pathologic features seen in PPD, this article helps to increase awareness so the diagnosis may not be missed.

Many thanks Dr Andrea Moy for the post journal club summary. See you all at the next #dermpathJC on August 30th at 9pm EST for a fun and lively discussion of a cutting edge #dermpath article in realtime via twitter! In July, #dermpathJC will be on a summer break.

Kind regards,

Silvija Gottesman, MD

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