Malignant form of hidroacanthoma simplex: A case report

Table 1 Summary of 10 malignant hidroacanthoma simplex cases

Case	Ref.	Age	Gender	Duration (yr)	Location	Size (cm)	Color	Ulceration	Clinical feature	Recurrence
1	Sun Kim et al[2], 2012	69	F	1	Suprapubic area	2 × 2	Pigmented	(-)	Verrucous nodule	No Recurrence
2	Lee et al[3], 2006	71	F	NR	Right knee	1.8 × 2.0	Pigmented	(-)	Hyperkeratotic tumor	NR
3	Ishida et al[10], 2009	72	M	3	Right thigh	1.7 × 1.2	Brown to black	(-)	Flat plaque	Liver and bone metastases before surgery
4	Bardach et al[4], 1978	70	F	15-20	Right leg	Not mentioned	Red	(-)	Irregularly shaped and crusted	NR
5	Yang et al[11], 2022	80	M	5	Left foot	1.2 × 0.8	Black	(-)	Elevated nodule	No Recurrence
6	Kohli et al[5], 2015	79	M	NR	Scalp	0.6 × 0.5	Pink	(+)	Papule	No Recurrence
7	Piqué et al[6], 1995	73	F	15	Right leg	3 × 3	Pigmented	(-)	Verrucous lesion	NR
8	Ansai et al[7], 1994	75	M	2	Right ankle	2.5 × 3.3	Pigmented	(-)	Verrucous plaque	No Recurrence
9	Lee et al[8], 2000	67	F	16	Right thigh	5 × 7	Pigmented	(-)	Verrucous lesion	NR
10	Takano et al[9], 1989	74	F	NR	Left thigh	1.5 × 1.5	Light brown	(+)	Elevated nodule	Died of cardiac and respiratory failure

NR: Not reported.

Table 2 Histopathological and immunohistochemical features of 10 cases

Case	Intraepidermal nests	Sharp delineation	Hyperkeratosis or acanthotic epidermis	Invasive growth	Nuclear and cytoplasmic pleomorphisms	Mitotic figure	Ductal structure	Immunohistochemistry
1	(+)	(-)	(+)	(+)	(-)	(+)	(+)	EMA (+), CK10 (+), CK14(+)
2	(+)	(+)	(-)	(-)	(-)	(+)	(-)	EMA (+), CEA (+)
3	(+)	(+)	(+)	(+)	(+)	(+)	(+)	NR
4	(+)	(+)	(+)	(-)	(-)	(-)	(+)	NR
5	(+)	(+)	(+)	(-)	(+)	(+)	(+)	CK5/6 (+), P63 (+), CEA (-) CK7 (-)
6	(+)	(+)	(+)	(-)	(+)	(+)	(+)	CytokeratinAE1/3 (+), EMA (+), CEA (+), CK7 (+)
7	(+)	(+)	(+)	(-)	(+)	(+)	(+)	CAM5.2 (+), CEA (+), S100 (+), EMA (+)
8	(+)	(+)	(+)	(+)	(+)	(+)	(-)	NR
9	(+)	(+)	(+)	(+)	(+)	(-)	(-)	EMA (+), CEA (+), S100 (+)
10	(+)	(+)	(-)	(-)	(+)	(-)	(-)	NR

EMA: Epithelial membrane antigen; CEA: Carcinoembryonic antigen; CK10: Cytokeratin10; CK14: Cytokeratin 14; CK5/6: Cytokeratin 5/6; CK7: Cytokeratin 7; CK19: Cytokeratin 19; P63: Transformation-related protein 63; CAM5.2: Cytokeratin CAM5.2; S100: S100 proteins; NR: Not reported; (+): Positive; (-): Negative.