214

Cancer 56: 1618-1623, 1985.

Light microscopic biopsy specimens from 48 patients were reviewed by two inde- pendent pathologists and classified as large cell carcinoma of the lung by 1981 World Health Organization (WHO) criteria. Sites of primary disease were hilar/medi- astinal in 26 patients, large mid-lung field in 17, and peripheral lung in 5. All material was examined by electron mi- croscopy (EM) for evidence of squamous ('squamous': 15 patients), glandular ('adenocarcinoma': 17 patients), or non- specific ('large cell': 14 patients) ul- trastructural differentiation. Two pa- tients had mixed adenosquamous features. There were 6 patients with Stage I tumors; 5, Stage II; 24, Stage IIIMO; and 13, Stage IIIMI. Of the 14 patients with large cell by EM, ii had unresectable Stage IIIMO or metastatic disease. Only 3 of 27 patients not undergoing resec- tion responded to combined modality the- rapy. There were two long-term survivors free of disease in the resected Stage IIIMO patient category. Overall median survi- val by stage was analyzed, with no sta- tistically significant difference between several of the stage groupings, sugge- sting a worse prognosis for the entire group overall compared to all patients with non-small cell lung cancer. The me- dian survival by EM subgroup was also without significant difference, both overall and within various stage groupings, despite more patients in the large cell category with advanced disease. These data support the unique behavior of patients with large cell carcinoma on light mi- croscopy, but fail to demonstrate that ultrastructural differentiations is of prognostic importance for response or survival.

Clear Cell Carcinoma of the Lung. Edwards, C., Carlile, A. Department of Histopathology, East Birmingham Hospital, Birmingham B9 5ST, U.K.J. Clin. Pathol. 38: 880-885, 1985.

Six tumours of the lung initially clas- sified as clear cell carcinoma, were stu- died. Examination of further material

by light and electron microscopy showed adenocarcinomatous differentiation in three cases and squamous differentiation in two. One case showed the features of a large cell anaplastic carcinoma. The clear appearance of the cytoplasm in pa- raffin sections was due to accumulations of glycogen that were partially removed during processing. It is concluded that clear cell carcinoma is not a single and separate entity.

Pulmona~7 Scar Cancer: A Pathologic Re-

appraisal.

Ignatius-Tak-Min-Kung, Irene-Oi-Lin-Lui, Shee-Loong- Loke, et-al. Department of Pathology, University of Hong Kong, Queen Mary Hospital, Hong Kong; Hong Kong. Am. J. Surg. Pathol. 9: 391-400, 1985.

A total of 49 consecutive specimens of lung cancer were collected prospectively at surgical resection or autopsy from 40 men and nine women, aged 40-74 years. Of the 49 tumors, the gross appearance of 22 fitted the description of a scar cancer, i.e., a tu- mor with pleural puckering and central pigmentation. Nineteen of the 'scar cancers' were peripheral (17 adenocarcinomas and two squamous cell carcinomas); three were central (one squamous cell carcinoma and two adenocarcinomas). In the 19 peripheral 'scar canbers', elastic stains demonstrated the presence of collapsed, unfibrosed lung tissue at the center with traction of the overlying pleura toward it. Elsewhere in the tumor, the elastic framework was either destroyed or expanded by tumor filling the alveolar spaces. None of the 'scar cancers' had a significant desmoplastic reaction that might other- wise explain the scarred appearance. It appeared that local atelectasis was solely responsible for the pleural puckering and central pigmentation. On the other hand, atelectatic lung tissue was not seen in the 27 cancers that did not have the appea- rance of a scar cancer. Tuberculosis was found in I0 of the 49 lung specimens. In only one specimen was the tuberculous lesion anatomically associated with the tumor. There was no evidence of pulmonary infarct in any of the specimens. The term 'scar cancer' was considered inappropriate as there was no preformed fibrous tissue. The scarred appearance was thought to be the result of localized pulmonary atelectasis owing to small airways obstruction by tumor. Association with tuberculosis was considered incidental.

Benign Clear Cell ('Sugar') t~nor of the Lung. A Light Microscopic, Histochemical, and Ultrastructu- ral Study with a Review of the Literature. Andrion, A., Mazzucco, G., Gugliotta, P., Monga, G. Institute of Pathological Anatomy and Histology, University of Turin, Turin, Italy. Cancer 56: 2657- 2663, 1985.

A case of a benign clear cell 'sugar' tumor of the lung is reported. Light microscopy showed a uniform proliferation of clear cells filled with abundant glycogen. At the ultrastructural level, tumor cells were rich in free monogranular and ro- sette-forming glycogen, but no membrane-bound gly- cogen was demonstrated. Some cells showed plasma membrane interdigitations, microvilli, and macula occludens-type junctions. Many polymorphic secre- tory and sporadic haloed neurosecretory-like granu- les were observed, but argyrophil strains as well as a large set of immunohistochemical reactions specific for APUD derivation had negative results. A literature review of this puzzling entity with particular emphasis on the histogenetic hypotheses is presented, and a derivation from epithelial non- ciliated bronchiolar (Clara)cells or epithelial se- rous cells is suggested.