Groin dissection was performed in adult male post-mortem subjects to establish the prevalence of inguinal canal "lipoma." Thirty-six body halves (age range 24-92 years) were studied. Of these, 27 (75%) contained a discrete mass of fat within the inguinal canal. This mass was always continuous with the preperitoneal fat through the deep inguinal ring. Nineteen of these 27 masses (70%), displayed a characteristic pedunculated form with a bulbous distal end. Eighteen of the 36 dissections (50%), revealed a mass more than 4 cm in length. Six dissections showed extension of the mass beyond the superficial inguinal ring and three of these six (8% of the 36 groins studied) showed distortion of the proximal spermatic cord with a mass at the superficial inguinal ring. The masses submitted for histology comprised mature adipose tissue and all but two of these were reported as having an adherent capsule. No significant correlation was found between mass length and either subject age or body mass index (BMI) but a statistically significant correlation between the length of the fat mass on the left and right sides was shown. This study demonstrates that the inguinal canal "lipoma" is a common feature in an adult male population and may be of sufficient size to cause clinical misdiagnosis. The high prevalence, characteristic location and appearance of the "lipoma" suggest a developmental etiology.

BackgroundThe depth of invasion by basal cell carcinoma (BCC) subtypes varies.ObjectiveTo investigate BCC invasion depth variation by subtype and anatomic site.MethodA prospective consecutive case series of excised BCC from 2009 to 2014 in a single Australian clinic.ResultsDescending mean depths for a total of 4,565 BCC cases by subtype were as follows: nodulocystic, 1.9 mm (n = 84, 95% CI: 1.70–2.03, P = 0.66); nodular, 1.6 mm (n = 947, 95% CI: 1.53–1.63, P < 0.0001); aggressive, 1.5 mm (n = 925, 95% CI: 1.44–1.59, P < 0.0001); superficial combined with nodular, 0.9 mm (n = 1,081, 95% CI: 0.83–0.90, P < 0.0001); and superficial, 0.3 mm (n = 1,528, 95% CI: 0.32–0.36, P < 0.0001). Deeper invasion was associated with increased chronic sunlight exposed sites. The deepest aggressive BCCs occurred on the neck with a mean depth of 1.8 mm (n = 46, 95% CI: 1.47–2.21).ConclusionWe found significant differences in the depth of invasion for BCCs by sex, subtype, and anatomic site. For BCC with characteristics matching this study, overall adequate microscopic excision depths are proposed: superficial, 1.0 mm; superficial combined with nodular, 2.0 mm; nodular, 3.0 mm; and aggressive, 3.0 mm.

Acantholytic SCC were more likely to be located on head sites with less median depth than non-acantholytic SCC. Increasing percentage of acantholysis within acantholytic SCC was not associated with a shift towards poor differentiation. Histologic margins of 1.2 mm may adequately excise small acantholytic SCC. No recorded deaths, low PNI and low recurrence rates suggests acantholytic SCC is low-risk.

Superficial BCC alone is more likely on younger females on trunk and limb sites. Small partial biopsies reported as sBCC may miss other BCC subtypes present with higher risk on facial sites for males and females. Males had smaller proportions of superficial only subtype BCC on facial and ear sites compared to females.

SummaryBackground. Invasive squamous cell carcinomas (SCCs) presents with different grades of differentiation and depths of invasion. Aim. To compare the grade of differentiation, tumour diameter and tumour depth by anatomical site in invasive SCC. Methods. Retrospective clinical and histopathological data on consecutive cases of SCC came from a clinic in Sydney, Australia were assessed. A multinomial logistic regression model was applied to compare grades of differentiation by age, sex, anatomical sites, and histological tumour maximum diameter and depth. Results. In total, 1666 SCCs were identified, including 82.1% (n = 1367) welldifferentiated, 13.3% (n = 222), moderately differentiated and 4.6% (n = 77) poorly differentiated SCCs. Patients with poorly differentiated tumours were more likely to be older and male (both P < 0.001). The most common site for poor differentiation was the scalp in men (n = 12; 15.6%) and the cheek or chin in women (n = 7; 9.1%). In the multivariate model, compared with well-differentiated SCC, older age was significantly associated with poorly and moderately differentiated SCC (P < 0.01 and P = 0.02, respectively). Larger tumour diameters were related to poor differentiation (P = 0.03). Ear, forehead and chest sites had increased tumour depth and poor differentiation.Conclusions. This study found increased rates of poorly differentiated SCC on the forehead and cheek for both sexes, while men displayed increased rates of poorly differentiated SCC on the bald scalp and the ears. Tumour diameter and depth increased as tumours varied from well-differentiated to moderately differentiated and from moderately differentiated to poorly differentiated. An increase in depth and increased prevalence of poorly differentiated tumours were found on the ears for men and on various facial sites for both sexes.