[Pathohistologic changes after induction cytostatic therapy with methotrexate (M), bleomycin (B) and cisplatin (P)--(MBP)].

In 22 patients with T3-4, N0-3, Mo squamous cell cancer of the head and neck (classification UICC 1979), who were treated with induction chemotherapy before surgical resection and postoperative radiotherapy, a comparative histopathologic examination of the prechemotherapy biopsy specimens and serial sections of the surgical specimens was performed. Chemotherapy consisted of 3 cycles every 3 weeks. On the first day of each cycle methotrexate (20 mg/m2) and 15 bleomycin, on the second day cis-diamminodichloroplatinum (60 mg/m2) and from day 3-8 15 mg bleomycin was given daily in a 6 hour infusion. Histopathologic grading of the prechemotherapy biopsies separated well from moderately well and from low differentiated squamous cell carcinoma. In addition the type of tumor growth - solid organoid or diffus reticular - and the mode of invasion were examined. The surgical specimens showed characteristic morphologic changes dependent on the quantity of the remaining tumor. Many tumor residues consisted of solid organoid well-differentiated carcinoma only. After good tumor response to chemotherapy tumor nests typically showed central cystic changes, which resembled pseudoglandular squamous cell carcinoma in cases with tendency towards keratinization or adenoid "basalioma", rarely solid "basalioma", if no tendency towards keratinization was found. Very small tumor nests in abundant local fibrotic tissue merely consisted of undifferentiated cells with absence of differentiated cells. In cases with tendency towards keratinization undifferentiated cells sometimes built one layer - complete or incomplete - around big foci of keratinization. The type of tumor growth - solid organoid or diffuse reticular - and the grade of differentiation showed marked accentuation after chemotherapy.