Early invasive squamous cell carcinoma recurrence rates: A study examining surgical margins, tumor surface diameter, invasion depth, and grade of differentiation in 1296 cases over 9 years.

BACKGROUND: Invasive squamous cell carcinoma (SCC) is typically treated by surgical excision. METHODS: Consecutive SCC excisions were reviewed prospectively in a single Australian center from 2009 to 2017. Cases were examined for recurrence by histopathologic margins, microscopic tumor surface diameter, invasion depth, grade of differentiation, and anatomic site. RESULTS: Over 9 years, 1296 cases were collected. By grade of differentiation maximum average microscopic surface diameters ranged from 8.0 to 9.6 mm and maximum average depths from 1.3 to 2.5 mm. Minimum average histopathologic margins for well, moderate, and poorly differentiated SCC, respectively, were 1.4, 1.1, and 1.3 mm. Recurrence occurred in 1.7% of well (n = 18/1084), 1.8% moderate (n = 3/165) and 6.4% in poorly differentiated (n = 3/47) SCC. No recurrence occurred beyond a histopathologic margin of 3.5 mm for well and 2.5 mm for moderately differentiated SCC. Highest recurrence for well-differentiated SCC by anatomic site was the lip (7.0%) then ear (4.6%). CONCLUSION: We found a recurrence rate of 1.0% for histopathologic margins of 1.5 mm with early well-differentiated SCC. The grade of differentiation and anatomic site had a larger influence on recurrence rates compared to the histopathologic margins. Poorly differentiated SCC and ear or lip sites require wider surgical margins.

Basal cell carcinoma: variation in invasion depth by subtype, sex, and anatomic site in 4,565 cases.

BACKGROUND: The depth of invasion by basal cell carcinoma (BCC) subtypes varies. OBJECTIVE: To investigate BCC invasion depth variation by subtype and anatomic site. METHOD: A prospective consecutive case series of excised BCC from 2009 to 2014 in a single Australian clinic. RESULTS: Descending 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). CONCLUSION: We 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.

Superficial basal cell carcinoma: A comparison of superficial only subtype with superficial combined with other subtypes by age, sex and anatomic site in 3150 cases.

BACKGROUND: Basal cell carcinoma (BCC) may present as superficial subtype alone (sBCC) or superficial combined with other subtypes. The objective of this study was to compare sBCC without or with other BCC subtypes by age, sex and anatomic site. METHODS: We retrospectively collected superficial BCC with the above characteristics from an Australian center during 2009 to 2014. RESULTS: We recorded 1528 sBCC and 1622 superficial BCC combined with other BCC subtype cases. Males numbered 2007 and females 1140. On males, head sites (forehead, cheek, nose and ear combined) compared to limb plus trunk sites displayed a higher incidence of superficial BCC combined with either nodular and or aggressive BCC subtypes (OR 13.15 CI 95% 8.9-19.5 P < .0001). On females a similar comparison also found a higher incidence of superficial BCC combined with solid subtype BCC on head sites compared to trunk and limb sites (OR 9.66 CI 95% 5.8-16.1 P < .0001). CONCLUSION: 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.

Parachordoma is not distinguishable from axial chordoma using immunohistochemistry.

Parachordoma is a rare soft tissue tumor that morphologically resembles chordoma of the axial skeleton but occurs in a peripheral site. A recent study reported immunohistochemical differences between chordoma and parachordoma. While both tumors were positive for cytokeratin (CK) 8/18 (as recognized by the antibody Cam5.2), S100 and epithelial membrane antigen (EMA), only the chordoma was positive for CK7, CK20, CK 1/5/10/14 (as recognized by the antibody 34betaE12) and carcinoembryonic antigen (CEA). It has since been suggested that tumors indistinguishable from chordoma that involve the periphery should be termed chordoma periphericum and that these tumors are distinct from parachordoma. In the current study, the clinical, radiological, pathological, immunohistochemical and ultrastructural features of a chordoma-like tumor involving the deep soft tissues of the lower leg of a 69-year-old woman are presented. Microscopically, the tumor had a pseudolobulated growth pattern and consisted of sheets, nests and cords of epithelioid cells, some with a physaliferous appearance, separated by abundant myxoid stroma. The tumor cells were positive for CK 8/18, EMA and S100, showed focal staining for CK7, and were negative for CK20, CK 1/5/10/14 and CEA. On the basis of these results a diagnosis of parachordoma was favored. For comparison, an immunohistochemical analysis of five axial chordomas was also performed. The chordomas showed positivity for CK 8/18 (5 of 5 cases), EMA (5 of 5 cases), S100 (5 of 5 cases), CK 1/5/10/14 (1 of 5 cases) and CK7 (1 of 5 cases). Stains for CK20 and CEA were negative in all five chordomas. The results of the present study suggest that the expression of antigens for CK 1/5/10/14, CK7, CK20 and CEA in chordoma might not be as common as what has been previously reported. The results also suggest that parachordoma might not be easily distinguished immunohistochemically from axial chordoma (and therefore also from so-called chordoma periphericum).

Inguinal canal "lipoma".

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.