An immunohistochemical study of the mesenchymal and epithelial components of pulmonary chondromatous hamartomas

Maldevelopment of intrapulmonary bronchial cartilage in congenital diaphragmatic hernia

BACKGROUND

Pulmonary hypoplasia is an important cause of morbidity and mortality in infants with congenital diaphragmatic hernia (CDH). This study aimed to verify our hypothesis that the abnormal development of bronchial cartilage as well as alveolar immaturity, might play a central role in hypoplasia of the lung in human CDH.

METHOD

We retrospectively analyzed autopsied lungs from 10 CDH cases and compared with nine age-matched controls to assess the bronchial cartilage and alveolar maturity using morphological techniques.

RESULT

Ki-67 and thyroid transcription factor-1 (TTF-1) expression in the alveoli significantly increased in bilateral lungs with CDH. The shortest distance from the bronchial cartilage to the pleura was significantly shorter in ipsilateral (left) lungs with CDH, showing a positive correlation with the radial alveolar count (RAC). Regarding the small bronchial cartilages less than 20 000 μm² , the average cartilage area significantly decreased in left lungs with CDH, and tended to decrease in right lungs with CDH. In addition, cartilage around the bronchi less than 200 μm in diameter tended to be smaller in left lungs with CDH. In contrast, regarding the cartilage around the bronchi 200 to 400 μm in diameter, the ratio of the total cartilage area relative to the bronchial diameter tended to be higher in left lungs with CDH, although there was a large variation.

CONCLUSIONS

These opposite directional cartilage abnormalities around the distal and more proximal bronchi support our hypothesis that abnormal development of bronchial cartilage might play an important role in the hypoplastic lung in CDH.

An unusual case of pulmonary hamartoma with predominant bronchial mucous glands in the peripheral lung

Pulmonary hamartoma (PH) is the most common benign lung tumor, comprising various amounts of mescenchymal components with entrapped epithelial components. We describe an unusual case of PH in the left lower lung lobe of a 60-year-old female. The tumor was 9 × 9 mm in size, light brown, weakly glistening, and microscopically found to be composed of well-developed epithelial and mesenchymal components without atypia. Both components were intermingled but without apparent transition. Epithelial components were occupied by predominant bronchial mucous glands. Serous glands, entrapped bronchioles, and clefts lined by respiratory epithelium were also apparent. Mesenchymal components including cartilage and fat were scattered, and swirling smooth muscle fascicles were interlaced with epithelial components. Collision tumor or other biphasic tumors were unlikely, and hyperplastic change in bronchial glands as in the rare conditions of intraoral minor salivary glands and epithelial entrapments by PH may explain these interesting histological findings. It is important to be aware of the possibility that a large number of bronchial mucous glands may be noted in the peripheral lung, and not to mistake this for other malignancies.

Videothoracoscopic identification of chondromatous hamartoma of the lung

Introduction

The main disadvantage of a videothoracoscopic procedure is the lack of touch sensation. The probability of easily finding the lesion is usually estimated according to computed tomography (CT).

Aim

To find useful parameters of location of chondromatous hamartoma of the lung parenchyma in relation to its size to assess the probability of successful search via a videothoracoscopic approach only.

Material and methods

A group of 55 patients operated on for chondromatous hamartoma of the lung at the First Department of Surgery in Olomouc from January 2006 to June 2011 was analyzed. Initially, the tumor's longest diameter and its nearest distance to the pleural surface were measured on CT scans. Subsequently, the surgery began using the videothoracoscopic approach. A short thoracotomy with direct palpation followed when videothoracoscopy failed.

Results

No significant differences in age, sex and side of localization between the group with and without successful videothoracoscopic detection were found. A significant difference was found in the median size (p = 0.026) and the depth of the tumor (p < 0.0001) and in the calculated index “tumor size/depth” (p < 0.0001). Deeper analysis revealed that the parameters “depth” and “index size/depth” are considered to be good predictors but the parameter “size” is not a suitable predictor.

Conclusions

The main predictors of successful videothoracoscopic detection of lung chondromatous hamartoma are considered to be the depth of the tumor in the lung parenchyma with a cut-off value ≤ 7.5 mm and the index “size/depth” with a cut-off value ≥ 1.54; the tumor size is not considered to be a good predictor.

Solitary fibroleiomyomatous hamartoma of the lung in a patient without a pre-existing smooth-muscle tumor

A solitary well-demarcated tumor was found in the left lung of a 53-year-old man. It was located in the posterior region of the lower lobe just adjacent to, but apart from, the pleura. It was resected by video-associated thoracic surgery. Macroscopically, the tumor was a whitish solid nodule without hemorrhage or necrosis, and it was 1.5 cm in diameter. Histologically, the tumor consisted of a proliferation of fibromuscular tissue in interlacing fascicles in which many tubular or cleft-like epithelial inclusions were involved. The epithelial inclusions showed cystic changes with goblet cell metaplasia in part, but no atypical changes. Other mesenchymal components such as cartilaginous, myxomatous or adipose tissues were not seen. The patient had no history of neoplasm, including smooth-muscle tumor. Thus, we diagnosed this tumor as a "true" fibroleiomyomatous hamartoma, as distinct from so-called fibroleiomyomatous hamartoma or benign metastasizing leiomyoma, which are usually found in the lungs of women who have had hysterectomies, as multiple fibromuscular nodules. We report here this rare case and we review and discuss published reports of fibromuscular tumors of the lung.