Giant Cell Lesions of Lungs: A Histopathological and Morphometric Study of Seven Autopsy Cases.

INTRODUCTION: Macrophages undergo fusion to form multinucleated giant cells (MGC) in several pathologic conditions. The exact mechanism of their generation is still unclear. MGC are a common feature of granulomas that develop during various inflammatory reactions. AIM: To study the histopathological features of giant cell lesions in lungs and correlate the characteristics of giant cells with other histopathological findings. Also, to determine the utility of morphometry to differentiate foreign body and Langhans MGC. MATERIALS AND METHODS: Seven cases were analysed. Specimen of lungs was grossed, sectioned and processed. Routinely, tissue sections were stained by Haematoxylin and Eosin (H&E) stain. Polarizing microscopy and special stains were employed in selected cases. Granulomas and MGC were counted and measured. Several other parameters like location, distribution, type and number of MGC, associated predominant inflammatory component and nature of granulomas were analysed. RESULTS: Five patterns of lesions were observed in seven cases. Aspiration pneumonia was seen in three cases (42.85%) and constituted the most common pattern. However, aspiration pneumonia as the only cause of MGC was seen in only one case (14.28%). Pulmonary tuberculosis and asteroid bodies constituted two cases (28.57%) each. Cryptococcal pneumonia and cholesterol clefts constituted one case (14.28%) each. Crypococci were demonstrated to be positively birefringent by polarized microscopy on Ziehl-Neelsen stained sections. Based on statistical analysis of morphometric data, a new index (NP index) was proposed to statistically categorize MGC into foreign body type and Langhans type. NP index value of ≤0.016 was found to be statistically significant (p<0.005) in foreign body MGC. It had high sensitivity and efficacy. CONCLUSION: MGC may not be always associated with granulomas. The mechanisms that lead to the occurrence of MGC, independent of granuloma needs to be elucidated. Morphometry may serve as a useful aid. But a pathologist has to rely on the morphological details to categorize MGC.

Double Right Coronary Artery Originating from Separate Ostia: A Report of Two Cases.

CONTEXT: Coronary artery anomalies are uncommon and most are incidental findings. Double right coronary artery (RCA) is a very rare coronary artery anomaly. CASE REPORT: We report two cases of double RCA incidentally found in electrocuted patients. Both cases showed double RCA arising from separate ostia. On microscopy, both right coronaries showed no significant pathology in the first case while in the second case, the posterior RCA showed features of obliterative arteritis. CONCLUSION: Although double coronary artery has been regarded as hemodynamically insignificant, it may be associated with atherosclerosis, acute coronary syndromes, and other anomalies. It is important to know the anatomic variants. Meticulous grossing and careful observation could unearth hidden anomalies.

Carcinoma within a fibroadenoma: a case report.

Carcinoma within a fibroadenoma is an extremely rare occurrence with a reported incidence of 0.1% and is most often diagnosed incidentally on post-operative examination of excision biopsy specimens. One such case is reported here for its rarity and also for stressing upon the need for compulsory excision of all breast masses clinically diagnosed as fibroadenoma and for highlighting the importance of histopathological evaluation of all breast masses irrespective of their clinical diagnosis as benign.

Giant cell tumor of skin.

Giant cell tumor of the skin is a rare entity showing gross and histological features similar to those of giant cell tumor of the bone. We report a case of malignant giant cell tumor of the thigh in a 55-year-old man. Histological features showed a biphasic population of mononuclear cells admixed with osteoclast-like giant cells. The nuclei of the giant cells were similar to those of the mononuclear cells. This tumor should be distinguished from a variety of cutaneous neoplasms that contain multinucleated giant cells.

Strong myotoxic activity of Trimeresurus malabaricus venom: role of metalloproteases.

Trimeresurus malabaricus is an endemic snake found in the Southern region of Western Ghats section of India along with the more widely distributed species like Naja naja and Daboia russelii. T. malabaricus venom is not lethal when injected (i.p.) up to 20 mg/kg body weight in mice, but causes extensive local tissue degeneration. N. naja and D. russelii are highly toxic (i.p.) with minimum local tissue damage in experimental mice. In this study a comparative analysis of local tissue damage of T. malabaricus venom is made with N. naja and D. russelii snake venoms of the Southern regions of Western Ghats. T. malabaricus venom exhibits caseinolytic activity 16 and 24 times more than N. naja and D. russelii venom. Inhibition studies with specific protease inhibitors reveal that the major proteases belong to metalloproteases. T. malabaricus venom hydrolyses gelatin and induces strong hemorrhagic activity in mice. Both N. naja and D. russelii fail to hydrolyze gelatin even at very high concentration and did not induce any hemorrhagic activity. With D. russelii venom small hemorrhagic spot was observed at the site of injection. The hemorrhagic activity of T. malabaricus venom is completely neutralized by metalloprotease inhibitors and not by serine protease inhibitor. The i.m. injection of T. malabaricus venom causes extensive degradation of muscle tissue within 24 h. The light microscopic observation of muscle tissue showed congestion of blood vessels and hemorrhage at the early stage followed by extensive necrosis of muscle fibers. The elevated levels of serum CK and LDH activity further supported the muscle degeneration. Such pathological symptoms were not seen with N. naja and D. russelii snake venom. The hemorrhagic and the muscle necrosis was completely neutralized by metalloprotease inhibitors and not by serine protease inhibitor strongly suggests that the major toxin component in the T. malabaricus venom is metalloprotease and its activity can be easily neutralized using chelating agents and its use in the first aid as chelation therapy is beneficial.