Cellular cannibalism and consequent thrombocytopenia in a patient with bone marrow metastasis of malignant pleural mesothelioma: A case report.

Cellular cannibalism is a tumor activity where a cell is engulfed by another cell. This process promotes tumor cell survival under unfavorable conditions. The current report describes an extremely rare case of thrombocytopenia resulting from cellular cannibalism in a patient with bone marrow metastasis due to malignant pleural mesothelioma (MPM). A 77-year-old male presented with hemothorax and thrombocytopenia. He was diagnosed with MPM of the sarcomatoid cell type. However, his disease progressed rapidly and he died 11 days after admission. Bone marrow aspiration revealed metastatic MPM cells that had engulfed other blood cells. Accordingly, the observed thrombocytopenia was attributed to cellular cannibalism by metastatic MPM tumor cells. To the best of our knowledge, this is the first reported case of thrombocytopenia due to cellular cannibalism in a patient with this type of malignancy (MPM). The results suggested that although MPM rarely metastasizes to the bone marrow, bone marrow aspiration could be useful in such cases.

Histomorphological Evidence of Cellular Cannibalism in Ameloblastoma.

AIM: To study the cellular cannibalism (CC) in the tumor cells of ameloblastoma. MATERIALS AND METHODS: Hematoxylin and eosin (HE)-stained sections of ameloblastoma cases (50) were retrieved from the archived specimens and screened for cellular cannibalism (CC) by stellate reticulum-like cells. Further characterization of CC was performed using CD68 and lysozyme antibodies. RESULTS: CC was observed in 15 (30%) cases [follicular 10 (66.66%), unicystic 3 (20%), and acanthomatous 2 (13.33%)]. In acanthomatous ameloblastoma, the CC was observed in the central metaplastic squamous cells, while in 3 cases of unicystic ameloblastoma, CC was seen in stellate reticulum-like cells of intraluminal (2) and mural proliferations (1). All the 15 cases of ameloblastoma showed a negative expression of CD68 as well as lysozyme. CONCLUSION: CC is a new addition to the pathogenesis of ameloblastoma.

Entosis: The emerging face of non-cell-autonomous type IV programmed death.

The present review summarizes recent experimental evidences about the existence of the non-cell-autonomous death entosis in physiological and pathophysiological contexts, discusses some aspects of this form of cell death, including morphological, biochemical and signaling pathways that distinguish non-cell-autonomous demises from other death modalities and propose to define this new modality of death as type IV programmed cell death.

Cellular cannibalism in giant cells of central giant cell granuloma of jaw bones and giant cell tumors of long bones.

AIM: The aim of the present study was to investigate the relationship of central giant cell granuloma (CGCG) and giant cell tumor of long bones (GCT) with respect to cannibalistic giant cells (GCs). METHOD: Sixteen cases each of CGCG and GCT were histopathologically analyzed for cannibalistic GCs. One hundred GCs were examined in each section, and the number of cannibalistic GCs was expressed in percentage. RESULTS: Cannibalistic GCs were seen in all cases of CGCG and GCT (100%). GCT showed significantly higher mean cannibalistic GC frequency (44.81 ± 1.013) than CGCG (32.06 ± 1.398), aggressive CGCG (38.17 ± 1.579), non-aggressive CGCG (28.40 ± 0.6360), non-recurrent CGCG (30.42 ± 1.417), and recurrent CGCG (37.00 ± 2.483). In aggressive CGCG, the mean cannibalistic GC frequency was significantly higher (38.17 ± 1.579) than the non-aggressive variant (28.40 ± 0.6360). Recurrent CGCG cases showed significantly higher mean cannibalistic GC frequency (37.00 ± 2.483) than non-recurrent cases (30.42 ± 1.417). Similarly, recurrent GCT showed significantly higher mean cannibalistic GC frequency (47.4 ± 4.97) than non-recurrent GCT (43.63 ± 3.1). CONCLUSION: The distinctness of CGCG and GCT was observed in terms of mean cannibalistic GC count. The assessment of cannibalistic GC in CGCG and GCT could help in predicting the biological behavior and grading of the tumor.

Non-cannibalistic tumor cells of oral squamous cell carcinoma can express phagocytic markers.

BACKGROUND: CD68 and lysozyme expression in cannibalistic tumor cells of oral squamous cell carcinoma (OSCC) is well established. Transformation of cancer cells into cannibalistic cells is a process involving sequential events. Initial event could be genetic expression of proteins that is required for execution of cannibalism. Hence, it is quite possible that some non-cannibalistic tumor cells can also show expression of cannibalistic markers (CD68 and lysozyme). METHODOLOGY: Formalin-fixed tissues of 30 OSCC cases with cellular cannibalism (CC) (positive control), 30 OSCC cases without CC, and 17 normal oral epithelium specimens (negative control) were subjected to immunohistochemical analysis for CD68 and lysozyme expression. RESULTS: OSCC with CC showed CD68 and lysozyme expression in 30 (100%) cases each {CD68: [weak: 21 (70%), strong: 9 (30%)]; lysozyme: [weak: 24 (80%), strong: 6 (20%)]}. In OSCCs without CC, CD68-positive tumor cells were present in 13 (43.33%) cases [weak: 10 (33.33%); strong: 3 (10%)] and lysozyme expression was present in 13 (43.33%) cases [weak: 12 (40%); strong: 1 (3.33%)]. Control group showed negative expression for CD68 and lysozyme in the oral epithelium. The CD68 and lysozyme expression in OSCCs without CC, OSCCs with CC, and control group showed statistically significant differences (P < 0.001). Significant correlation was also observed between CD68 and lysozyme expression and different grades of OSCC. CONCLUSION: CD68 and lysozyme expression in non-cannibalistic tumor cells of OSCC can be related to CC.