title: [Atypical tumor regression].
abstract: A 67-year-old man presented with a poorly differentiated squamous cell carcinoma of the esophagus diagnosed by biopsy. After neoadjuvant radiochemotherapy the gastroesophagectomy specimen showed diffuse polymorphic and anuclear cell residues ranging from 35 µm to 46 µm in size. Immunohistochemically, PanCK and AE1-3 revealed a positive staining while CD68 and MIB1 showed a negative staining. The retrospective anamnesis revealed that the patient had chronic polyarthritis as underlying illness, for which reason he had been taking humira and methotrexate, a cytostatic drug, for many years. Therefore, the development of the tumor might have been enhanced by these drugs. Electron microscopic analysis confirmed that the avital akaryote cell residues represented a special type of tumor regression. Complete tumor regression level IV without vital rest tumor tissue based on Baldus et al. was diagnosed.
authors.affiliation: Gerhard-Domagk-Institut für Pathologie, Albert-Schweitzer-Campus 1, Gebäude D17, 48149, Münster, Deutschland, barbara.heitplatz@ukmuenster.de.
authors.forename: B
authors.initials: B
authors.lastname: Heitplatz
authors.forename: K-M
authors.initials: KM
authors.lastname: Müller
mesh_terms: D000068879:Adalimumab; D000368:Aged; D061067:Antibodies, Monoclonal, Humanized / Q000009:adverse effects / Q000627:therapeutic use; D000964:Antimetabolites, Antineoplastic / Q000009:adverse effects / Q000627:therapeutic use; D018501:Antirheumatic Agents / Q000009:adverse effects / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000188:drug therapy; D001706:Biopsy; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000473:pathology* / Q000628:therapy; D002471:Cell Transformation, Neoplastic / Q000187:drug effects / Q000473:pathology; D059186:Chemoradiotherapy, Adjuvant; D003131:Combined Modality Therapy; D004938:Esophageal Neoplasms / Q000139:chemically induced / Q000473:pathology* / Q000628:therapy; D016629:Esophagectomy; D004947:Esophagus / Q000187:drug effects / Q000473:pathology; D005743:Gastrectomy; D006801:Humans; D008134:Long-Term Care; D008297:Male; D008727:Methotrexate / Q000009:adverse effects / Q000627:therapeutic use; D008854:Microscopy, Electron; D009365:Neoplasm Regression, Spontaneous / Q000473:pathology*; D018365:Neoplasm, Residual / Q000139:chemically induced / Q000473:pathology* / Q000628:therapy
chemical_list: D061067:Antibodies, Monoclonal, Humanized; D000964:Antimetabolites, Antineoplastic; D018501:Antirheumatic Agents; D000068879:Adalimumab; D008727:Methotrexate