Since diagnostic difficulty is frequently experienced in malignant round cell tumors of the head and neck, the author attempted to apply recently developed immunohistochemical techniques to improve objective parameters of diagnostic accuracy. Materials consisted of four cases of rhabdomyosarcoma (embryonal and alveolar), two cases of olfactory neuroblastoma, one pigmented and two amelanotic cases of malanoma, three cases of small cell carcinoma and ten cases of malignant lymphoma. The lymphoma cases were selected from 45 cases of malignant lymphoma on the basis of good fixation and preservation of tissue. As controls, five cases of adrenal neuroblastoma and one case of mesenchymal chondrosarcoma predominantly consisting of small round cells were also selected. Formalin-fixed paraffin sections were used. For the immunohistochemical study, the author used a midification of the PAP (peroxidase anti-peroxidase) method by Sternberger and the ABC (avidin-biotin peroxidase complex) method by Hsu et al. If necessary, especially in using monoclonal antibody, PAP-ABC method was used. Antisera used in this study included those of CPK-MM, myoglobin, myosin, tropomyosin, S-100protein, neuron-specific enolase (NSE), human neuroblastoma antigen (HNA), neuron cell surface antigen (NCSA), IgM, la-like antigen (fa), T-lymphocyte antigen (T). The results obtained were as follows: 1) Although CPK-MM, myoglobin, myosin and tropomyosin were positive in all four cases of rhabdomyosarcoma, myoglobin tended to be demonstrated in relatively large differentiated rhabdomyoblasts with eosinophilic cytoplasm but CPK-MM was detected even in smaller tumor cells. Therefore, a combination of these markers rather than only a single one is recommended for differentiation from other round cell tumors. 2) Neuron-specific enolase, neuroblastoma antigen and neuron cell surface antigen were positive in all two cases of olfactory neuroblastoma as well as the five adrenal neuroblastomas. Therefore, histogenetic similarity of these tumors is suggested. 3) None of the 11 markers was demonstrated in the three small cell carcinomas. 4) S-100 protein was positive in two amelanotic melanoma and one case of mesenchymal chondrosarcoma, while the pigmented malignant melanoma was negative for it. S-100 protein is not specific to a single tissue or a single tumor, but nevertheless it appears useful for differential diagnosis between tumors, if it is known which tumors are always negative for it. 5) The PAP-ABC method appears to be significantly better for the detection of a small amount of antigen than either the PAP or the ABC alone. This combination technique was successful in detection of monoclonal antigens such as neuroblastoma antigen, neuron cell surface antigen, Ia-like antigen, T-lymphocyte antigen. 6) It is said that antigen substance is not always well-preserved in malignant lymphoma. However, in this study, IgM was demonstrated in seven out of 10 cases of malignant lymphoma using paraffin sections of formalin-fixed specimen. In conclusion, the author demonstrated that enzyme immunohistochemistry is very useful for objective differential diagnosis between round cell tumors of the head and neck including small cell carcinoma by presenting objective reliable information. This methodology holds great promise as a supplementary technique in improving the diagnostic accuracy of conventional pathological evaluation.
In order to clarify the true nature of the basic cells in pleomorphic adenoma of the salivary glands, the author attempted to study the tumor by means of immunohistochemistry and electron microscopy. Materials consisted of 32 cases of pleomorphic adenoma, including 21 from the parotid, 4 from the submandibular gland and 7 from the minor salivary glands. Antisera used in this study included those of keratin, lysozyme, secretory component and a1-anti-chymotrypsin for identification of epithelial nature, myosin for myoepithelial nature and fibronectin for nonepithelial nature. Antiserum for S-100 protein was also used, because of its almost constant demonstration in the tumor cells constituting this tumor. These antigenic substances were detected by the PAP (peroxidase anti-peroxidase) method and ABC (avidin-biotin peroxidase complex) method using paraffin sections of formalinfixed specimens taken at surgery. Ten of these cases were also observed by electron microscope, and the ultrastructural features were compared with the results of immunohistochemistry. All tumors were histologically categorized into three main portions such as 1) solid-tubular portion (STP), 2) transitional portion (TP) and myxo-chondroid portion (MCP). Attention was focused on the localization of the afore-mentioned markers in each of these three portions. (Results) All antigenic substances for demonstration of epithelial nature were present in tumor cells, but keratin appeared to be the most reliable one and was demonstrated not only in the cells of STP, but also in single or clustered tumor cells of TP and MCP. Myosin, which was constantly positive in myoepithelial cells of the intercalated ducts or acini of normal salivary gland tissue, was also demonstrated by the ABC method not only in some tumor cells of both MCP and TP, but also in STP, especially in the outer cells of double-layered tubular structures. Myosin-positive cells were also seen in the inner layer of these tubular structures. S-100 protein was not detected in normal salivary glands, but all tumors of pleomorphic adenoma were positive, with a tendency for the degree of positivity to increase from the STP through the TP and the MCP. Ultrastructural study showed both myofilamentous structures and tonofilaments in STP tumor cells. Tonofilaments were also recognized in the MCP cells. Tumor cells with pericellular chondroid matrix resembling hyaline cartilage were observed at the MCP. Judging from the findings, including keratin and myosin immunochemistry and also the ultrastructural features of the tumor cells in the three portions mentioned above, it is concluded that this tumor is predominantly composed of cells with duct epithelial or/and myoepithelial natures. These duct epithelial and myoepithelial cells are intimately related with each other even in this tumor, although non-epithelial chondromyxoid change is seen in the tumor. Pleomorphic adenoma presumably arises from the duct structure which is composed of both duct epithelium. Cells suggesting stem cells which are considered to be the origin of this tumor by some investigators, were not observed in this study.
The cancer chemotherapy with cis-diamminedichloroplatinum (II) (CDDP) was studied in human squamous cell carcinoma transplanted to nude mice and in 37 head and neck cancer patients. 1. In nude mice experiment, CDDP revealed statistically significant (p<0.01) antitumor effect in transplanted squamous cell carcinoma, and the effect was not related to the schedule of administration of CDDP. 2. Of 14 patients treated with CDDP alone 12 patients were evaluable. Of the previously untreated four patients one revealed complete response and two partial response (response rate 75%). In recurrent patients one out of eight showed partial response. (response rate 12.5%). 3. Twenty-three patients were treated with CDDP (100mg/m2) and 5-FU (1000 mg/m2/day×4 or 5 days) infusion. Five complete response and six partial response were seen out of 19 previously untreated patients (response rate 58%). One complete and one partial response were observed out of four recurrent patients (response rate 50%). 4. Twenty-three previously untreated patients received radical radiotherapy or surgery after the induction chemotherapy, CDDP alone or with 5-FU combination, and 14 patients alive with free of the disease. 5. Clinical effect was more marked after 2 courses of chemotherapy. The side effects were not seen in both the first and the second course of the treatments. 6. Neoadjuvant chemotherapy by CDDP or especially CDDP+5-FU seems to offer a new modality of treatment to extend the scope of radical therapy for advanced head and neck carcinomas and preserving function of the oropharyngeal region.