Phylloides Tumor With Numerous Thanatosomes ("Death Bodies"): A Report of Two Cases and a Study of Thanatosomes in Breast Tumors

Undifferentiated Pleomorphic Sarcoma With Hyaline Globules (Thanatosomes)

Hyaline globules (HGs) or thanatosomes belong to a well-defined microscopic phenomenon common to any cell type, representing eosinophilic and round-shaped intracytoplasmic inclusions as a result of altered cellular metabolism. We experienced a case of undifferentiated pleomorphic sarcoma (UPS) of the left thigh, immunoreactive diffusely for CD99 and p16INK4a and focally for alpha-smooth muscle actin. HGs were multifocally clustered in the cytoplasm of the tumor cells. An ultrastructural study using a formalin-fixed, paraffin-embedded block was performed to visualize HGs in the UPS cells. Light microscopically, multifocally clustered HGs were PAS-positive with diastase-resistance and fuchsinophilic in Masson's trichrome staining. HGs were immunoreactive for cleaved caspase-3, but negative for ubiquitin. Ultrastructurally, apoptotic tumor cells contained clusters of small-sized electron-dense globules. Granular material was often deposited in the globule matrix. The formation of the HGs is supposedly related to an apoptotic process of the tumor cells. Though a nonspecific and minor microscopic finding, HGs in soft tissue sarcomas may represent a useful histologic marker of enhanced cell turnover and/or ischemic injury. This is the third report describing HGs in UPS.

Pancreatic Intraductal Papillary Mucinous Neoplasm with Hyaline Globules (Thanatosomes): Report of Two Cases

Hyaline globules (HGs; thanatosomes) represent a morphologic entity representing a metabolic imbalance common to all cell types. HGs, intracytoplasmic eosinophilic globular accumulations of proteinaceous material of varying sizes, have been observed in varied tumors and benign tissues. Different explanations have been proposed for their formation, according to the tumor type and anatomic location. An earlier study suggested that HGs were closely related to apoptosis. There are some reports describing HGs in pancreatic neoplasms, such as intraductal oncocytic papillary neoplasm, solid-pseudopapillary neoplasm, oncocytic endocrine neoplasm, and invasive ductal adenocarcinoma; however, this is the first report describing HGs in pancreatic intraductal papillary mucinous neoplasm (IPMN). An ultrastructural study was performed to visualize HGs in two pancreatic IPMNs of gastric type (one non-invasive malignancy and another adenoma). Light microscopically, intracytoplasmic HGs were clustered multifocally. HGs were periodic acid-Schiff-positive and diastase-resistant, and fuchsinophilic with Masson’s trichrome stain. The diameter ranged from 4.7 to 20.6 μm (mean: 13.3, median: 14.1). They were mainly seen at the supranuclear position and occasionally with subnuclear location. Ultrastructurally, HGs were round in shape and homogenously electron-dense without mitochondria or chromatin-like condensation. The nuclei of HGs-containing mucous columnar cells appeared intact without evidence of apoptosis. It is worth emphasizing that HGs in the pancreatic IPMN of gastric type belong not to apoptotic bodies but to proteinaceous secretory materials.

Invasive breast carcinoma with hyaline globules ("thanatosomes")

Hyaline globules (thanatosomes) have been observed in many neoplastic and non-neoplastic processes. They represent terminal cytoplasmic structures associated with cytoplasmic blebbing, which are related to cell injury and apoptosis. Thanatosomes are reported rarely in breast tumors. Here we describe a case of invasive breast cancer of no special type with abundant thanatosomes.

Carcinosarcoma of the Gallbladder with Chondrosarcomatous Differentiation and Intracytoplasmic Eosinophilic Hyaline Globules (Thanatosomes): A Report of a Case and Review of the Literature

A 52-year-old woman presented with abdominal pain and vomiting. Computed tomography (CT) scan of the abdomen revealed a huge exophytic gallbladder mass displacing or invading the surrounding structures. The patient underwent radical cholecystectomy, transverse colectomy, distal gastrectomy, and liver bed resection. Histologically, the tumor showed both carcinomatous and sarcomatous components, with prominent chondrosarcomatous differentiation. In addition, several malignant cells showed intracytoplasmic eosinophilic hyaline globules (Thanatosomes). The tumor showed metastatic deposits to the omentum, the liver, and the peripancreatic lymph nodes. We report this unusual case and present a review of all cases of carcinosarcoma of the gallbladder with chondrosarcomatous differentiation.

Breast carcinoma with numerous large "thanatosomes"

Intracytoplasmic and stromal eosinophilic hyaline globules (HGs) have been observed in various neoplastic and nonneoplastic conditions. Thanatosomes are also such HGs seen invariably associated with increased apoptosis and may contain nuclear fragments, occasionally observed in high-grade tumors. We are reporting a case of high-grade breast carcinoma with this striking morphological feature. Their probable nature, pathogenesis, and significance are discussed with review of literature.