Primary hepatic clear cell myomelanocytic tumor. Case report and review of the literature

A case of hepatic clear cell myomelanocytic tumor in a 31-year-old woman presenting clinically with abdominal pain is reported. Histopathologic examination showed a lesion characterized by a population of large epithelioid cells with clear or eosinophilic granular cytoplasm, rich in glycogen. Immunohistochemically, the tumor cells were positive for HMB-45, Melan-A and muscle-specific actin, but negative for epithelial markers, desmin, S-100 protein, and neuroendocrine markers. Ultrastructurally, the tumor cells had abundant glycogen, well-developed rough endoplasmic reticulum, microtubules and aberrant melanosomes. Clinical and pathologic features with a brief review of the relevant literature for hepatic CCMMT as a variant of perivascular epithelioid cell tumor (PEComa) are discussed.     

Epithelioid leiomyosarcoma with osteoclast-like giant cells in the rectum

We report a rare case of rectal epithelioid leiomyosarcoma with osteoclast-like giant cells. A 71-year-old Japanese man was admitted to a hospital with melena. Results of a colonoscopy test revealed a polypoid tumor in the rectum, and a biopsy specimen from the lesion showed a sarcoma; the patient underwent rectosigmoidectomy. At gross inspection, the tumor measured 8 x 7 x 4 cm and was polypoid with ulcerations. Necrotic and hemorrhagic foci were scattered. Microscopically, the tumor consisted of 2 cell types: malignant tumor cells with epithelioid features and benign-appearing osteoclast-like giant cells. The tumor cells were polygonal and epithelioid in shape and had eosinophilic or clear cytoplasms, with scattered giant tumor cells. Immunohistochemical examination revealed that the tumor cells were positive for vimentin, muscle actin, alpha-smooth muscle actin, and desmin, whereas the osteoclast-like giant cells were positive for CD68, leukocyte common antigen, and lysozymes. We diagnosed this case as epithelioid leiomyosarcoma with osteoclast-like giant cells. To the best of our knowledge, this is the first case of rectal epithelioid leiomyosarcoma with osteoclast-like giant cells.     

Malignant epithelioid angiomyolipoma of the kidney in a patient with tuberous sclerosis: an autopsy case report with p53 gene mutation analysis

We report an autopsy case of malignant epithelioid angiomyolipoma in a 36-year-old male tuberous sclerosis patient. He had been diagnosed to have a bilateral renal tumor 20 years previously. The left kidney had been surgically resected at the age of 34, and the left renal tumor was pathologically diagnosed as classic angiomyolipoma and epithelioid angiomyolipoma. He suddenly died of cardiac arrest, and at autopsy the right kidney weighed 7120 g. The tumor presented with massive necrosis invading the inferior vena cava, but was not hemorrhagic. Microscopic examination revealed tumor cells varying in size with a predominantly solid proliferation pattern and marked atypical large cells with vesicular nuclei and abundant eosinophilic cytoplasm. Mitotic figures were often encountered, and atypical forms were also present. Metastatic lesions were identified in the right lung, liver, diaphragm, and mesentery. Immunohistochemical examination showed epithelioid angiomyolipoma cells that were focally reactive for HMB-45 and showed diffuse positive staining for Melan-A. No mutation was detected in the p53 gene by polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP) analysis despite diffuse immunoreactivity for p53. This case was proven to be malignant because of the occurrence of distant metastases, and showed that p53 mutations are not always associated with malignant transformation in epithelioid angiomyolipoma.     

Primary perivascular epithelioid cell tumor of the bladder

The perivascular epithelioid cell family of tumors includes angiomyolipoma, clear cell “sugar” tumor of the lung, lymphangioleiomyomatosis, and clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres. Less frequently, perivascular epithelioid cell tumors arise in various other locations throughout the body including soft tissue, bone, and visceral organs. We report a case of a 23-year-old man who presented with 2-month history of frequent micturition and odynuria. Based on clinical examination, ultrasound computed tomography imaging, surgical operation, and histopathologic studies, a definitive diagnosis was made. Further characteristic images and pathology of this disease are discussed.     

Primary adrenal gland epithelioid sarcoma: A case report and literature review

Epithelioid sarcoma is a malignant mesenchymal neoplasm with morphologic and immunophenotypic epithelioid differentiation, which rarely arises in solid organs. We report a case of primary epithelioid sarcoma in the adrenal gland of a 31‐year‐old female. The patient initially presented with nausea and rectal bleeding, and subsequent imaging studies revealed a 4.4 cm left adrenal gland mass and left retroperitoneal lymphadenopathy. Clinical and radiological studies did not reveal tumor elsewhere in the patient. Histologic features were those of epithelioid sarcoma, proximal type with cohesive clusters of epithelioid tumor cells harboring frequent mitoses, and areas of necrosis. Immunohistochemical stains showed strong, diffuse expression of epithelial markers (pancytokeratin), and CD34 and Fli‐1. Partial and focal positive staining of CK7 was also noted. Nuclear expression of SMARCB1 (INI‐1) protein was lost. ERG was negative in this case. We believe that this is the second‐case report of a primary adrenal gland epithelioid sarcoma. Fli‐1 positivity was seen in our case, and ERG was negative as shown in some recent publications regarding epithelioid sarcomas.     

Primary perivascular epithelioid cell tumor in the rectum: A case report and review of the literature

Perivascular epithelioid cell tumor (PEComa) is a rare collection of tumors arising in a wide array of anatomic locations. It is characterized by the presence of a peculiar population of myomelanocytic marker-positive perivascular epithelioid cells, and is commonly detected in the uterus. The colorectal area is an uncommon site for primary PEComa. In this study, we describe a 17-year-old patient presenting with a rectal polyp. Histologically, the tumor consisted of sheets of round to polygonal epithelioid cells with clear and granular cytoplasm, and a prominent capillary network. Some of the tumor cells were positive for Fontana-Masson staining. Immunohistochemically, the tumor cells were positive for HMB-45, and were negative for cytokeratin, vimentin, S-100 protein, actin, desmin, EMA, CD34, and c-kit. After finding melanosomes or premelanosomes at the ultrastructural level, the diagnosis of PEComa was made. Although PEComa arising within the intestinal tract is unusual and clinically unexpected, PEComa should be considered in the differential diagnosis of rectal polypoid lesions.     

Intraosseous epithelioid malignant peripheral nerve sheath tumor of the phalanx. Case report

We report the first case of intraosseous epithelioid malignant peripheral nerve sheath tumor (MPNST) occurring in the phalanx. The patient was a 50-year-old Japanese man with an intramedullary lytic lesion of the proximal phalanx. Microscopically, the tumor was composed of epithelioid cells or polygonal cells, forming large cell nests with central necrosis. Most tumor cells were diffusely and strongly immunopositive for S-100 protein and vimentin, and negative for cytokeratin, epithelial membrane antigen, carcinoembryonic antigen, alpha-smooth muscle actin, and HMB-45. Laminin-positive material was discontinuously demonstrated between the individual tumor cells. Electron microscopy showed prominent external lamina. Our case indicated that laminin is useful for differentiating epithelioid MPNST from metastatic carcinoma and malignant melanoma.     

Malignant clear-cell myomelanocytic tumor of broad ligament—a case report

Clear-cell myomelanocytic tumors (CCMT) of the perivascular epithelioid cell tumor (PEComa) family have been recently reported. We report a case involving a 12-year-old girl. The tumor (9 × 7.5 × 7 cm) was a firm, tan–gray mass with heavily dark pigmentation, massive hemorrhage, and necrosis, and was located in the right broad ligament attached to the right ovary. Histologically, the tumor was composed of polygonal cells exhibiting diffuse hemorrhage, multifocal necroses, and vascular invasion. Most of the tumor cells contained melanin pigments with Fontana–Masson positivity and ultrastructurally suspicious, membrane-bound premelanosomes. Immunohistochemical staining was positive against HMB-45 and focally positive for smooth muscle actin. The tumor recurred in the form of multiple conglomerated masses of the right iliac fossa, with the greatest measuring up to 3.8 cm in dimension, within 1 year. Most CCMT are believed to originate from falciform ligament/ligamentum teres. To the best of our knowledge, this is the second report of a CCMT arising in the broad ligament with typical morphology and contributory ancillary results. Further study for proper subclassification of the PEComa family should be validated, not by anatomic site but by clinical behavior.     

Angiomyolipoma of the large intestine: report of a case.

A case of an angiomyolipoma of the large intestine occurring in a 55-year-old man without evidence of tuberous sclerosis is reported. Endoscopically, the lesion resembled a sessile adenomatous polyp. The tumor measured 1 cm. Histologic examination revealed a lesion composed predominantly of spindle and epithelioid cells with significant nuclear atypia. Mitoses were rare. The tumor was strongly positive for HMB-45, CD68, vimentin, desmin, and smooth muscle actin. Rare scattered cells reacted with CD34. No residual tumor was found in the resected colon.     

Epithelioid hemangioendothelioma of the spinal cord: Description of a case with cytogenetic analysis

A case of epithelioid hemangioendothelioma of the cauda equina is reported. The patient presented with rapidly worsening low back pain. Magnetic resonance imaging revealed a sharply demarcated intradural lumbar lesion. A bluish-red lesion, attached to the filum terminale, was removed. The patient is alive without evidence of recurrence 18 months after surgery. The tumor was composed of variously sized vessels lined by epithelioid endothelial cells with clear cytoplasm and centrally located, moderately atypical nuclei. These cells were immunoreactive for CD31 and factor VIII antibodies. Cytogenetic analysis disclosed two clones: 44-45X, - Y [cp3]/46XY[11]. Epithelioid hemangioendothelioma may arise in several sites, the most common being soft tissues. It is a borderline tumor that may recur, may metastasize, and rarely causes death. The present case appears to be the first example of epithelioid hemangioendothelioma of the spinal cord.     

Preoperative diagnosis of clear cell "sugar" tumor of the lung by computed tomography-guided fine-needle biopsy and core-needle biopsy

Clear cell "sugar" tumor (CCST) of the lung is a very rare benign neoplasm believed to arise from epithelioid cells of perivascular differentiation. This tumor is typically diagnosed by thoracotomy. To our knowledge, only 2 case reports of CCST have been previously published: one case in which cytologic findings were subsequently confirmed histologically and ultrastructurally to be CCST, and one case of CCST diagnosed preoperatively by transbronchial core-needle biopsy. We here depict an additional case of CCST of the lung that was preoperatively diagnosed by computed tomography-guided transthoracic fine-needle aspiration biopsy and core-needle biopsy. We underscore the importance of cytologic and histologic correlation and the role of ancillary studies in differentiating this lesion from other primary or metastatic clear cell tumors of the lung.     

Uterine epithelioid endometrial stromal sarcoma presenting as a "cervical polyp"

Although appearance of conventional uterine endometrial stromal sarcoma is easily recognized on histology, it may uncommonly assume unusual appearances such as uterine tumor resembling ovarian sex-cord tumor, thereby hindering its diagnosis. Recently, its manifestation as an epithelioid neoplasm was described. In this report, we detail yet another instance where this tumor adopted an epithelioid morphology, presenting itself as a polyp extruding from the cervical os in a 41-year-old Chinese woman. Both the polypectomy and subsequent hysterectomy specimens revealed a predominant proliferation of CD10-negative, caldesmon-negative, and CD117-positive epithelioid cells set within a stroma containing vascular proliferation resembling endometrial stromal tumor. Areas of typical low-grade endometrial stromal sarcoma containing spindle cells that were focally positive for CD10 and negative for CD117 were present in close association with the epithelioid areas. The differential diagnoses and possible implication of CD117 positivity are discussed.     

Epithelioid hemangioendothelioma with osteoclast-like giant cells

Epithelioid hemangioendothelioma is an unusual entity of intermediate malignant vascular tumors and rarely admixes with multinucleated osteoclast-like giant cells. We describe such a case in a 50-year-old woman with an 1-year follow-up period. When the patient was 39 years old, a 0.7 x 1-cm firm mass was found in the left neck. She developed ascites three years later. At that time, the specimen from the neck mass was excised and found to be composed of cords of epithelioid cells in a myxoid hyaline stroma. Scattered intracytoplasmic vacuoles were seen. Immunohistochemical studies confirmed the diagnosis of epithelioid hemangioendothelioma. Abdominal ultrasonography and computed tomographic scan revealed multiple low density areas in the liver. Eleven years later, a metastatic lesion was found in the thoracic spine at the level of Th7-8. The histologic findings were basically similar to those of the left neck mass. However, because of the presence of Kp-1-positive multinucleated osteoclast-like giant cells throughout the tumor, the thoracic lesion was diagnosed as an epithelioid hemangiothelioma with osteoclast-like giant cells. This unique form of epithelioid hemangioendothelioma is extremely rare and should be distinguished from other benign and malignant tumors with osteoclast-like giant cells.     

Epithelioid cellular chordoma of the sacrum: a potential diagnostic problem

We describe a sacral chordoma composed of solid nests of epithelioid cells. The tumor originated in the presacral area. Extensive clinical workup did not reveal any other lesion in the patient. In contrast to typical chordomas, this tumor contained only rare physaliferous cells, had no myxoid stroma, and was immunohistochemically unreactive with the antibody to S-100. The diagnosis of chordoma was supported by electron microscopy, which showed that the tumor cells contained numerous mitochondria surrounded by profiles of rough endoplasmic reticulum. The abundance of mitochondria, the narrow intercellular spaces, combined with a lack of glycogen, and a lack of extracellular myxoid material accounted for the epithelioid appearance of the tumor. We report this case to point out that the cellular chordomas can appear epithelioid in the sacrum and they may resemble metastatic squamous or transitional cell carcinomas.     

Epithelioid angiomatous nodule of the nasal cavity

Epithelioid angiomatous nodule (EAN) is a recently described cutaneous vascular lesion with epithelioid features. We report two additional cases occurring in an unusual location in the nasal cavity. The patients were two young adults (17 and 26 years) presenting with recurrent unilateral epistaxis. Computerized tomography scan and endoscopy revealed small tumors that had developed in the nasal septum and the turbinate, measuring 1 and 1.5 cm, respectively. Endoscopic resection was performed. No recurrence was observed in the follow-up. Pathological examination revealed a well-limited but unencapsulated nodule composed of large epithelioid cells with round nuclei. Some tumor cells contained intracytoplasmic vacuoles. Mitotic activity was low without necrotic areas. Tumor cells were strongly immunostained with antibodies to CD34 and CD31. The main differential diagnosis is an epithelioid hemangioma sharing many morphologic features with EAN. We report these cases to inform of a possibly unusual location of EAN.     

Hepatic epithelioid angiomyolipoma with an unusual pathologic appearance: expanding the morphologic spectrum

Hepatic epithelioid angiomyolipoma (AML) is a rare lesion that is characteristically composed of a predominant or exclusive population of epithelioid cells coexpressing melanocytic and myogenic markers. The cystic variant of epithelioid AML is exceedingly uncommon. In this study, we present the clinicopathological features of a case of hepatic epithelioid AML with remarkable cystic degeneration in a 34-year-old female as well as with a literature review. A magnetic resonance imaging scan revealed a well-defined 30 cm × 25 cm hepatic mass. Sectioning of the well-defined mass revealed a non-encapsulated tumor that was multiloculated with amorphous necrotic tissue and hemorrhagic fluid. The inner cystic wall was rough and brownish-black in color. Microscopically, the tumor largely consisted of epithelioid cells that comprised approximately 95% of the total neoplastic components but also contained some spindle myoid cells, mature fat, and a thick-walled vasculature. Both intracellular and extracellular hyaline globules were frequently identified. Necrosis and invasive growth patterns were also present. By immunohistochemistry, spindle-epithelioid neoplastic cells were variably positive for Melan-A, HMB45, and SMA but were uniformly negative for epithelial and hepatocytic markers. This is the third report of a cystic AML in liver. The patient was followed for 71 months without any evidence of metastasis or recurrence.     

Multifocal presentation of gangliocytic paraganglioma in the mediastinum and esophagus

Gangliocytic paraganglioma (GP) is a rare, typically benign tumor that shows neuroectodermal (neurosustentacular or Schwannian and neuronal) and neuroendocrine differentiation. Once thought to arise exclusively in the periampullary region as a solitary lesion, recent reports have documented both origin of GP in a variety of extra-duodenal sites as well as synchronous multifocal presentation of the tumor. Herein, we describe the first reported case of simultaneous occurrence of GP in the superior mediastinum and esophagus. A mass in the mid-distal esophagus and a separate mass in the superior mediastinum at the thoracic inlet were found in a 58-year-old woman by computed tomography scan. Subsequent biopsy of the superior mediastinal mass showed nests of epithelioid tumor cells coexisting with ganglioneuromatous elements, whereas biopsy of the esophageal mass showed nests of epithelioid cells with interspersed ganglion cells. The epithelioid tumor cells showed diffuse immunohistochemical expression of keratin (CAM 5.2), chromogranin, and synaptophysin supporting true neuroendocrine differentiation; ganglion cells expressed S-100 protein and neurofilament protein; and the spindled elements expressed S-100 protein, neurofilament protein, and glial fibrillary acidic protein indicating Schwannian differentiation. The finding of another GP occurring outside the periampullary region bolsters the argument for a stem cell origin of this unusual tumor.