Epidermal Cyst on the Scalp Induced by Forceps Injury During Delivery: A Case Report and Epidemiological Analysis of 3949 Patients

Figures & data

Figure 1 Well-defined swelling with a depression on the top of the scalp.

Figure 2 Epidermoid cyst lined by stratified squamous epithelium having granular layer and filled with laminated keratin material. (a) Bar length = 3mm. The rectangular box shows the structure of the cyst wall. (b) Bar length = 400μm.

Table 1 Number and Mean Age Distribution of Patients with Epidermal Cyst for Year

Year	No. of Patients		Mean Age		Ratio (Male/Female)
	Male	Female	Male	Female
2011	42	31	36.62±18.50	41.87±15.44	1.3548
2012	117	77	37.52±17.24	42.49±16.06	1.5195
2013	127	88	35.18±16.45	37.34±19.86	1.4432
2014	121	85	36.61±15.53	40.96±17.38	1.4235
2015	143	117	38.48±17.51	35.76±17.80	1.2222
2016	248	213	37.77±17.42	39.06±18.42	1.1643
2017	340	279	36.00±17.59	38.50±16.78	1.2186
2018	527	384	36.81±15.65	39.03±17.00	1.3724
2019	528	482	35.78±16.11	38.73±16.94	1.0954

Table 2 Age and Sex Difference of Patients with Epidermal Cyst

Age Group	No. of Patients			Percentage
	Males	Females	Total
0–9	53	57	110	2.79
10–19	190	133	323	8.18
20–29	646	408	1054	26.69
30–39	486	375	861	21.80
40–49	315	291	606	15.35
50–59	259	257	516	13.07
60–69	158	142	300	7.60
70+	86	93	179	4.53
Total	2193	1756	3949	100.00

Figure 3 Age skewed distribution of patients with epidermal cyst (skewness=0.474). SD, standard deviation.

Figure 4 Age and sex difference of patients with epidermal cyst.

Table 3 Age and Site Difference of Patients with Epidermal Cyst

Age Group	Site						Total
	Scalp	Face	Neck	Trunk	Limbs	Perineum
0–9	7	53	4	11	7	1	83
10–19	5	138	19	29	26	5	222
20–29	24	427	58	161	49	21	740
30–39	18	274	93	204	41	16	646
40–49	9	182	65	104	25	22	407
50–59	16	174	34	98	22	22	366
60–69	7	93	25	62	12	3	202
70+	7	64	12	23	8	3	117
Total	93	1405	310	692	190	93	2783
Percentage	3.34	50.49	11.14	24.87	6.83	3.34	100.00

Figure 5 Typical lesions in different sites. (A) Scalp. (B) Face. (C) Neck. (D) Trunk. (E) upper limb. (F) Palm of hand (G) Ventral of penis. (H) Great lips of pudendum. (I) Sole of foot.

Figure 6 Different lesion’s location of patients with epidermal cyst.