Mona Abdel-Halim

CLINICAL QUESTION: A 26-year-old woman presented with asymptomatic skin coloured to whitish keratotic papules on the vulva, inguinal folds and inner thighs of 6 years duration. She had no similar lesions elsewhere and no family history. A biopsy was taken from one of the papules.Review the high-quality, interactive digital Aperio slide at http://virtualacp.com/JCPCases/jclinpath-2018-205434/ and consider your diagnosis. WHAT IS YOUR DIAGNOSIS?: Darrier's diseaseHailey-Hailey diseaseGenital wartsPapular acantholytic dyskeratosis of genitocrural areaPemphigus vegetansThe correct answer is after the discussion.

DISCUSSION: Papular acantholytic dyskeratosis (PAD) of the genitocrural area is a peculiar acantholytic dermatosis with dyskeratosis localised to the vulva and inguinal folds with possible extension to the thighs and perineum.1 It mainly involves young or middle-aged females.1 Cases affecting males and involving genitalia, thighs and perianal region have been reported.2 It represents an allelic variant of Hailey-Hailey disease as heterozygous mutations in gene (intron 5 and exon 24) have been reported in some cases.3 Clinically, PAD of the genitocrural area is typically characterised by solitary or grouped keratotic flesh coloured or white papules.1 Other clinical presentations include: vesicles, bullae, patches and plaques.4 Although the lesions are mainly asymptomatic, patients may experience variable degrees of itching or burning sensation.Histopathologically, the lesions show hyperkeratosis, hypergranulosis, acanthosis and acantholytic dyskeratosis in the spinous layer (figure 1). Typically, direct immunoflourescence (DIF) is negative.5 jclinpath;jclinpath-2018-205434v1/F1F1F1Figure 1Photomicrograph representing histopathological findings: hyperkeratosis, hypergranulosis, acanthosis and acanthloytic dyskeratosis involving the spinous layer; 254×143 mm.The most important differential diagnoses of this sporadic condition include: Darier's and Hailey-Hailey, both of which are familial. Hailey-Hailey involves also other flexural areas and presents with eroded crusted lesions with foul odour. Pathologically, the acantholytic process in PAD of the genitocrural area is rather focal compared with the broad zone of acantholysis in Hailey-Hailey, and columns of parakeratosis overlying suprabasilar acantholysis are characteristic of Darier's disease. Although, some cases of PAD of the genitocrural area can present with vesicles and bullae, the presence of dyskeratotic cells and the negative DIF speaks against pemphigus.Treatment options for this condition include topical and systemic retinoids. Cryotherapy and laser have been also reported to be effective. Topical steroids might be effective in reducing pruritus.

ABSTRACT: Crystalglobulinemia (CG) is a rare disorder characterized by crystallization of monoclonal immunoglobulins in the microcirculation leading to multiorgan vascular thrombosis and ischemic injury. The main cause of CG is multiple myeloma. We report a case of a 52-year-old man who presented with widespread necrotizing plaques and ulcerations. A skin biopsy revealed eosinophilic rectangular-shaped crystals occluding the lumina of blood vessels with no associated features of vasculitis. The crystals were Periodic acid-Schiff stain positive. The findings were diagnostic of CG. Extensive work up lead to the discovery of multiple myeloma. Awareness of CG is important because it may be the first presenting manifestation of an underlying serious hematological malignancy.