Pigmented purpuric eruption in the anogenital area

presented by

David Elpern MD, (1) Williamstown, MA, USA

Ron Yaar MD, PhD, (2) Boston, MA, USA

January 22, 2011

(1) Dermatologist, Skin Clinic, Williamstown, MA, USA
(2) Assistant Professor, Director of Dermatopathology Training, Boston Medical Centre, Boston, MA, USA


62 yo woman with dermatitis of perineal area and back for a few months


62 yo female

3 months

Hyperpigmentation was noted by the patient’s gynecologist in posterior fourchette in November of 2010.  Initial biopsy was signed out as “lichen sclerosis, vulvar melanosis.”  A second opinion was sought.  The patient was asymptomatic.  She also noted an asymptomatic “red spot” on her med back.

Physical Examination

Extensive hyperpigmentation of perirectal and posterior vaginal area.  There is speckled hyperpigmentation of mid-back and more cephalad a macular erythematous patch with punctate areas of erythema suggestive of “cayenne pepper spots.”  Similar subtle erythema is noted in pudendal area.


Laboratory Data



Histopathology:  Biopsies from back and pudendal area show similar findings: telangiectasia, extravasated erythrocytes, papillary dermal fibrosis, a moderate band-like lymphohistiocytic infiltrate. There was no homogenization of the papillary dermis.  These findings are “most suggestive of lichenoid purpura.”

Pic 1 (from Perineum A) - Scanning magnification demonstrates a superficial, band-like infiltrate with essentially no epidermal or deep dermal inflammation.

Pic 2 (from Perineum A) - Higher magnification reveals that the infiltrate is lymphohistiocytic and contains scattered extravasated erythrocytes.

Pic 3 (from Mid Back 1) - Scanning magnification again demonstrates a superficial, band-like infiltrate with essentially no epidermal or deep dermal inflammation.

Pic 4 (from Mid Back 1) - Higher magnification again demonstrates that the infiltrate is lymphohistiocytic and contains scattered extravasated erythrocytes.

Pic 5 (from Mid Back 1) - Sections stained for iron (PERLS stained sections) demonstrate focal positivity (blue staining), consistent with hemosiderin deposition (similar results were seen in PERLS stained sections from Perineum A).

Perineum B and Mid back 2 were considerably less exciting from a histopathologic point of view.


Pudendal and back process c/w “Lichenoid Purpura.”

Reason for presentation

Dr. Ron Yaar, the dermatolopathologist of record, drew our attention to a reference on the rare association between pigmented purpura and mycosis fungoides.

  1. Have you seen a pigmented purpuric eruption in the anogenital area? 
  2. Should one be concerned about a possible CTCL with this bland pathology?
  3. Would you entertain another diagnosis here?

Toro JR, Sander CA, LeBoit PE., Persistent pigmented purpuric dermatitis and mycosis fungoides: simulant, precursor, or both? A study by light microscopy and molecular methods. Am J Dermatopathol. 1997 Apr;19(2):108-18

Department of Dermatology, University of California, San Francisco, USA.

Mycosis fungoides (MF) can present with purpuric lesions, and rare patients who seemed to have persistent pigmented purpuric dermatitis (PPPD) have developed MF.

We recently encountered two patients referred to our cutaneous lymphoma clinic who had PPPD rather than MF and two others who appeared to have both conditions, leading us to explore the histologic similarities of these diseases. We examined specimens from 56 patients with PPPD to determine the frequency of MF-like histologic configurations, namely, the psoriasiform lichenoid, psoriasiform spongiotic lichenoid, and atrophic lichenoid patterns.

We also noted the degree of spongiosis, epidermotropism, papillary dermal fibrosis, lymphocytic atypia, and epidermal hyperplasia, the number of extravasated erythrocytes and siderophages, and the distribution of lymphocytic infiltrate within the epidermis.

In 29 of 56 patients, there were patterns typically seen in MF. PPPD can feature lymphocytes aligned along the epidermal side of the dermoepidermal junction, with few necrotic keratinocytes, as can MF. Papillary dermal edema occurred frequently in PPPD but not in MF, while lymphocytes in MF but not PPPD had markedly atypical nuclei and had ascended into the upper spinous layer.

Given these similarities, we tested for clonality of the T-cell population using a polymerase chain reaction assay for gamma-chain rearrangements. Clonal populations were present in three of three and one of two specimens from patients with both PPPD and MF, but also in 8 of 12 specimens typical of lichenoid patterns of PPPD.

These findings raise the possibility that the lichenoid variants of PPPD are biologically related to MF.


pigmented purpuric dermatosis, lichenoid purpura, mycosis fungoides

Comments from Faculty and Members

Khaled El-Hoshy MD, Dermatologist, Livonia, MI, USA on January 23, 2011

I would manage as pigmented purpuric eruption, with a f/u visit bi-annually. Re-biopsy in the future, should circumstances change.

Jerome Litt MD, Dermatologist, Beachwood, Ohio, USA on Jamuary 23, 2011

Rule out drug eruption. How about a list of drugs?

Robert Rudolph MD, Clinical Professor of Dermatology, University of Pennsylvania, Philadelphia, PA, USA on January 23, 2011.

With that biopsy I'd be concerned about an incipient MF. 

Surely doesn't look like a pigmented purpura to me (even the lichenoid type found on legs), a FDE (my first thought at glancing at the photo), or true lichen planus.

I'd repeat the biopsies and perform "stains for MF cell types" from both sites.

Bhushan Kumar MD, Consultant Dermatologist, Chandigarh, India on January 23, 2011

Could it be lichen aureus?

Nasser Altamimi MD, Dermatologist, Sana, Yemen on January 23, 2011

How about Lichen sclerosus? this is very common in menopausal women

Bashir Zendah MD, Senior Registrar, Department of Dermatology, Tripoli Medical Centre Tripoli, Libya on January 27, 2011

Lichenoid  purpura  is the first  possibility with this picture  but she need further follow up and re-biopsy  to exclude M F  changes later on.

Julian Manzur M.D., Dermatologist, Havana, Cuba on February 6, 2011

My first diagnosis is Fixed drug eruption.

Neil Shah MD, Dermatologist, Mayo Clinic Rochester, USA on February 22, 2011

Interesting case. I could see lichenoid PPD with the closeup photo you show. Arguing against LSA would be lack of gross architectural distortion (were the labia minora structurally normal?). Would follow clinically for progression if a question of CTCL. Photomics don't look good for CTCL at this point, but look good for PPD.

PPDs respond fairly rapidly to rutin + vitamin C. (J Am Acad Dermatol. 1999 Aug;41(2 Pt 1:207-8). I've had success with a product called Hy-Bio (available on Amazon.com) which contains rutosides and vitamin C. Usually complete resolution within 14-28 days. In this case useful as a therapeutic and diagnostic maneuver.

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