SQUAMOUS CARCINOMA OF THE LUNG WITH OSTEOCARTILAGINOUS STROMA

Pleural chondroid metaplasia in a background of IgG4 plasma cell rich chronic inflammatory infiltrate: report of a rare case with review of literature

Mesothelial reactive and degenerative changes secondary to inflammatory conditions, toxin exposure, neoplastic and non-neoplastic disease are often encountered in routine histopathology practice. Herein, we report a very rare case of pleural chronic inflammation with features suggestive for IgG4-related disease associated with the formation of a nest of mature, benign looking cartilage in the pleura of a middle age male patient. The review of the pertinent literature reveals that to date, only few cases of chondroid metaplasia or benign tumor (choristoma) are reported in mesothelium and only occasionally in this change is found in the pleura.

Pulmonary adenocarcinoma with heterotopic ossification

Pulmonary adenocarcinoma is a common malignancy that often involves calcification; however, bone formation in primary lung adenocarcinoma is extremely rare. In ten cases of primary pulmonary adenocarcinoma with heterotopic ossification, we detected immunoreactivity against TGF-beta1, osteopontin, osteocalcin and Runx2 in the fibroblastic stroma and tumor cells within the area of ossification. Our results suggest that in primary pulmonary adenocarcinoma, heterotopic ossification occurs via intramembranous bone formation. To our knowledge, only 11 other cases of pulmonary adenocarcinoma with heterotopic ossification have been reported. Here, we present ten cases of pulmonary adenocarcinoma showing heterotopic ossification with a description of previously published results and the histogenesis of heterotopic bone formation.

Human urinary bladder-carcinoma cells are non-osteoinductive

Small pieces (ca. 2-3 x 3-5 mm) of the urinary-tract mucosa from noninvasive papillary transitional-cell carcinomas of the bladder (ca. urotheliale papillare, n = 33), invasive transitional-cell carcinomas of the bladder (ca. urotheliale papillare infiltrans, n = 6, papillary transitional-cell carcinomas of the bladder with squamous metaplasia (ca. urotheliale papillare cum metaplasia planoepitheliale, n = 4), transitional-cell carcinomas in situ (ca. urotheliale in situ, n = 2), and squamous-cell carcinomas of the bladder (ca. planoepitheliale, n = 2) were grafted intramuscularly into cortisone-immunosuppressed mice to test the ability of transformed transitional epithelium to induce heterotopic osteogenesis. Altogether, 156 implants from 47 cases of urinary bladder carcinoma were performed. Histological examination of implants, excised 10-17 days later, revealed relatively good survival of the grafted epithelium, which had proliferated and, in some cases, formed cysts and islands but failed to induce heterotopic osteogenesis in the surrounding host tissues. In nine implants prepared from four cases (noninvasive papillary transitional-cell carcinoma of the bladder and invasive papillary transitional-cell carcinoma of the bladder, two cases each) a small amount of cartilage and/or bone was found in the stroma of grafted tissue. The rarity of this phenomenon--together with the observation that implants of normal human urinary-tract mucosa have never induced the formation of cartilage/bone, whereas in a similar system, dog or guinea-pig grafts are osteogenic--suggests that the cartilage/bone present in the stroma of implanted cancers is the result of metaplasia of the stroma of the neoplasm and not the product of any osteoinductive potency of human urothelium.

Heterotopic ossification in a lymph node with metastatic follicular carcinoma of thyroid: a case report

Metastasis of follicular thyroid carcinoma in a cervical lymph node associated with heterotopic ossification in a 34-year-old white female is presented. Pertinent gross and microscopic pathology is described and the literature is reviewed briefly. Bone formation in thyroid neoplasm has not been reported previously, except for bone metastases of medullary carcinoma.