Skin nontumor

Contributed by Omar P. Sangueza, M.D. and Mark R. Wick, M.D.

• Suprabasal acantholysis with vesicle formation is the principal microscopic finding
• Elongation of rete ridges with focal acantholysis and eosinophils may be the only early changes in Grover disease
• Main 4 histopathological patterns are:
  • Pemphigus vulgaris / foliaceous-like: predominantly limited to suprabasal acantholysis, with basal keratinocytes attached to basement membrane forming a characteristic tombstone appearance
  • Darier-like: suprabasal acantholysis of keratinocytes with scattered apoptotic or dyskeratotic cells within various levels of the epidermis
  • Spongiotic: edema within epidermis, causing separation of keratinocytes and prominent intracellular bridges
  • Hailey-Hailey-like: suprabasal acantholysis of all levels of the epidermis without significant dyskeratosis (dilapidated brick wall appearance)
• More than one pattern can be seen in the same setting
• Other newly described histopathological pattern include: (Am J Dermatopathol 2010;32:541)
  • Porokeratotic: presence of oblique columns of parakeratosis over areas of epidermis devoid of granular layer, with occasional dyskeratotic cells in the upper epidermal layers and a tendency to basal vacuolization
  • Lentiginous: elongation of the rete ridges with some basal hyperpigmentation resembling a solar lentigo or Dowling-Degos disease
  • Vesicular: intraepidermal vesicles with minimal spongiosis or acantholysis on their sides
  • Lichenoid: vacuolar damage and slight lymphocytic infiltrate at the dermoepidermal junction, with occasional dyskeratosis and barely identifiable acantholysis
  • Dysmaturative: disordered keratinocyte maturation with nuclear pleomorphism and slight hyperchromasia (Am J Dermatopathol 2018;40:642)
  • Epidermolytic hyperkeratosis-like pattern (Am J Dermatopathol 2014;36:358)

Contributed by Omar P. Sangueza, M.D.

• HSV1, HSV2, VZV (J Cutan Pathol 2017;44:486)

A white, elderly male presented with multiple pruritic papule involving the trunk. Which of the following is true regarding the diagnosis of this lesion?

1. Associated mucosal lesion is diagnostic
2. ATP2A2 gene abnormality is a common finding
3. Net pattern of IgG and C3 on direct immunofluorescence
4. Sparing of acrosyringium can be a helpful feature

D. Sparing of acrosyringium can be a helpful feature. Transient acantholytic dermatosis (Grover disease) can mimic variable vesiculobullous entities, especially pemphigus vulgaris, Darier and Hailey-Hailey. Differentiation depends on clinical presentation, microscopic findings and direct immunofluorescence findings. One microscopic finding that can help to differentiate between pemphigus vulgaris and Grover disease is adnexal structure and acrosyringium involvement in the former.

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Reference: Transient acantholytic dermatosis

Which of the following case scenarios is typical for transient acantholytic dermatosis (Grover disease)?

1. 17 year old man with crusted popular lesions involving head and neck
2. 20 year old woman with flaccid blisters involving the axillae and inframammary region
3. 40 year old woman with oral blisters and flaccid bullae involving the trunk
4. 60 year old man with erythematous papule involving the trunk

D. 60 year old man with erythematous papule involving the trunk. Transient acantholytic dermatosis (Grover disease) is most common in middle aged to elderly, Caucasian men. It most commonly manifest as a vesicular eruption of the trunk.

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Reference: Transient acantholytic dermatosis