case_images: PMC11144422_01
case_images: Clinical manifestations of the patient. There is a coin-sized macules at the bottom right of his waist, which developed into an ulcer at the center. The bottom of the ulcer was uneven and infiltrative, with a few shallow erosions in the surrounding rash. The ulcer was hard on touch.
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case_images: The ulcer felt hard to the touch (Figure 1).
case_images: Histopathological findings in the vertical section. The brown macules exhibited hyperkeratosis with columnar parakeratosis. Dyskeratotic cells are observed in the epidermis beneath the parakeratosis column. Additionally, mild hyperplasia and hypertrophy of the spinous layer and slight lymphocytes infiltration in the superficial dermis were observed. (HEx200). Columnar parakeratosis: .
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case_images: Histological examination revealed that the brown macules exhibited hyperkeratosis with columnar parakeratosis (as indicated by the red arrow in the Figure 2). Additionally, mild hyperplasia and hypertrophy of the spinous layer and slight lymphocyte infiltration in the superficial dermis were observed (Figure 2).
case_images: Plaque biopsy results. The epidermis proliferates irregularly, mainly as squamous cells, with some cell clumps growing infiltratively in the dermis. Infiltration of inflammatory cells into superficial and middle dermal layers (HEx200). Squamous cells: . Inflammatory cell infiltration: .
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case_images: Biopsy of the lesion within the plaque revealed irregular epidermal proliferation with obvious cell atypia which mainly comprised squamous cells (as shown by the black triangle in the Figure 3) with pathological karyokinesis (as indicated by the green arrow in the Figure 4). Figure 3), and a new diagnosis of DSP and SCC was confirmed. Following radiotherapy, the patient ceased to experience SCC, but PK remained untreated.
case_images: Atypia of tumor cells with pathological karyokinesis is evident. (HE x 400). Pathological karyokinesis: .
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case_images: Biopsy of the lesion within the plaque revealed irregular epidermal proliferation with obvious cell atypia which mainly comprised squamous cells (as shown by the black triangle in the Figure 3) with pathological karyokinesis (as indicated by the green arrow in the Figure 4).