We performed a clinicopathological analysis of 305 cases of primary cutaneous invasive squamous cell carcinoma (SCC) diagnosed in Tokushima University hospital in the past 25 years. We proposed a new clinicopathological classification of SCC based on epidemiological factors and divided it into nine categories; actinic keratosis type, bowen type, keratoacanthomatous type, cystic type, genital type, cicatricial type, radiodermatitis type, xeroderma pigmentosa type, and miscellaneous type. We examined the clinicopathological characteristics in each category such as favorite locations and prognosis. Among the clinical characteristics of those cases, such as sex ratio and age at the time of the excision, the favorite sites were similar to those in former reports in Japan. The actinic keratosis type is a significant type with little metastasis, but the radiodermatitis type and the genital type showed high metastatic rates. The case that occurred on the face showed little metastasis, but the cases on the lower limbs and genitalia had high metastatic rates. Cases with a tumor thickness of less than 4 mm showed lower metastatic rates than those with a tumor thickness of more than 4 mm. We divided those 25 years into five year segments as investigation periods and examined the numbers of cases, sex ratios, and the frequencies of the actinic keratosis type, the Bowen disease type, and the other types and found that these factors were essentially equal.
To assess the difference in quality between genuine steroidal ointments and generics, we attempted to investigate the solubility of drugs in ointment bases and their permeability through hairless rat skin. The solubility of corticosteroid in ointment bases differed greatly between the genuine product and the generics. There was a clear relationship between the solubility of corticosteroid in the ointment bases and the permeability of corticosteroid when the ointment bases were similar. These experiments demonstrated that there are great differences in pharmaceutical characteristics between genuine steroidal ointments and generics. These results suggest that, during the switch from steroidal ointments to generics, it is absolutely necessary to keep patients under observation.
From October 2002 to December 2009, we performed sentinel node biopsies (SNB) in 135 cases of skin tumors, including melanoma, squamous cell carcinoma (SCC), Paget’s disease, and adnexal tumors, using a combination method of dye and radioisotopes. Sentinel lymph nodes (SLN) were identified in 129 of the 135 cases (identification rate; 95.6%). SLNs were assessed by histopathology and immunohistochemistry for the presence of metastases. The incidences of metastasis in melanoma, SCC, Paget’s disease and adnexal tumors were 35.2%, 2.3%, 25.0% and 21.1%, respectively. The metastatic rate of SLN in each T-classification category was as follows: Tis 0%, T1: 0%, pT2: 10%, pT3: 53.3%, and pT4: 62.5%.Thus, the metastatic rates of SLN were positively correlated with the T-classification category. SLNs from 41 melanoma patients were further assessed by reverse-transcriptase polymerase chain reaction (RT-PCR) for the presence of micrometastases. RT-PCR analysis revealed metastases in 24 of 41 patients (58.5%). Our results suggest that SNB should be utilized in patients with non-melanoma malignant skin tumors as a method for diagnosing lymph node metastasis. Further studies are needed to define criteria for performing SNB in patients with non-melanoma malignant skin tumors as well as those with melanomas.