Solitary fibrous tumor with malignant potential arising in sublingual gland

A rare case is described of a solitary fibrous tumor (SFT) with malignant potential arising in the sublingual gland. A 59-year-old man presented with a 4-month history of a slowly enlarging painless mass in the center of the floor of the mouth. The tumor was a well-demarcated, firm mass with a multicystic lesion. The tumor exhibited highly cellular areas of spindle cells with patternless architecture alternating with hypocellular areas. The tumor cells were positive for CD34 and bcl-2 as well as vimentin, and negative for epithelial, myogenic, neurogenic and histiocytic markers. The tumor cells formed multiple satellite nodules around dilated ducts in the multicystic lesion, indicating infiltrative growth. In addition, areas exhibiting higher cellularity with increased mitoses were noticed in the satellite nodules, although cellular atypia was not obvious. These findings led to a final diagnosis of SFT with malignant potential. There has been no recurrence or metastasis for 27 months after the surgery. Solitary fibrous tumor of the salivary gland must be differentiated from various spindle cell neoplasms including myogenic, peripheral nerve sheath, fibroblastic and fibro-histiocytic spindle cell neoplasms, hemangiopericytoma and myoepithelioma. In addition to characteristic morphological features, an immunohistochemical positivity for CD34 and bcl-2 may aid in the diagnosis of SFT.     

Primary pancreatic leiomyosarcoma with metastasis to the liver diagnosed by endoscopic ultrasound‐guided fine needle aspiration and fine needle biopsy

Primary pancreatic leiomyosarcomas are rare tumors of the pancreas that are usually diagnosed after resection or by biopsy. One case in the literature has utilized endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) cytology. We report a second case of a primary pancreatic leiomyosarcoma that yielded diagnostic material on EUS‐FNA cytology. A 72‐year‐old female presented with 3–4 months of abdominal pain. A CT scan showed a large heterogeneous, lobulated pancreatic head and uncinate mass and multiple hypoattenuating liver lesions. An EUS‐FNA was performed on one of the liver lesions with a 25‐gauge needle, yielding an adequate sample with lesional cells. The initial read was a spindle cell neoplasm. A subsequent endoscopic ultrasound‐guided fine needle biopsy with a 22‐gauge needle was performed on the pancreatic head mass to rule out two primaries and to provide tissue for a mitotic index in the case of gastrointestinal tumor. Both the cell block of the EUS‐FNA and the core biopsy were equally cellular and showed interlacing spindle cells that stained positive for SMA and negative for DOG‐1, CD 117, and CD34. In addition, the core biopsy of the pancreas stained positive for Desmin. A diagnosis of a primary pancreatic leiomyosarcoma was made and the patient was started on systemic chemotherapy. Primary pancreatic leiomyosarcomas are rare pancreatic tumors that may yield diagnostic material by EUS‐FNA with a 25‐gauge needle. Diagn. Cytopathol. 2016;44:1070–1073. © 2016 Wiley Periodicals, Inc.     

Solid pancreatic hamartoma

A case of solid pancreatic hamartoma in a 58-year-old Japanese woman is presented. She had no symptoms, and a pancreatic mass was incidentally found on screening ultrasonography 4 months before admission. The patient was not alcoholic and had no history of pancreatitis. Physical examination and laboratory data were unremarkable. Preoperative imaging demonstrated a nodule in the body of the pancreas, measuring 2.0 cm in maximum diameter, which showed marked delayed enhancement during dynamic CT. The patient underwent a distal pancreatectomy under the preoperative diagnosis of pancreatic endocrine tumor and had an uneventful postoperative course. A well-demarcated solid nodule, 1.9 cm in diameter, was evident in the body of the pancreas. Microscopically, the lesion was composed of non-neoplastic, disarranged acinar cells and ducts embedded in a sclerotic stroma with elongated spindle cells, lacking discrete islets. The stromal spindle cells were immunoreactive for CD34 and CD117. The histological diagnosis was solid hamartoma of the pancreas. There was no recurrence 5 months after surgery. Herein is reported a case of solid hamartoma of the pancreas and review of the literature. A search through the literature found only two cases of solid hamartoma of the pancreas, among the 14 cases previously reported as pancreatic hamartoma.     

Paratesticular solitary fibrous tumor: a case report and review of literature

Solitary fibrous tumor (SFT) is a rare spindle cell neoplasm that usually arising from the pleura, but has been reported in diverse extrapleural sites. Urogenital localization is rare, and only several cases of paratesticular SFT have been reported. In the present report, we present the case of a 61-year-old male suffering from a paratesticular SFT. A surgical excision of the lesion was performed. The tumor was well circumscribed and consisted of a mixture of bland spindle cells and dense collagen bands. Immunohistochemical studies showed positive reactivity for CD34, CD99 and vimentin, but stained negative for CD117, S100, SMA, HMB45, Desmin and CD68. All these clinicopathologic features are suggestive of the diagnosis of paratesticular SFT.     

Pancreatic acinar cell carcinoma extending into the common bile and main pancreatic ducts

Acinar cell carcinoma (ACC) of the pancreas is relatively rare, accounting for only approximately 1% of all exocrine pancreatic tumors. A 69-year-old man was found to have a mass lesion measuring approximately 4 cm in diameter in the pancreatic head on ultrasound, abdominal dynamic CT, and percutaneous transhepatic cholangiography. Magnetic resonance cholangiopancreatography showed defect of the lower common bile duct (CBD) due to obstruction by the tumor cast. Histopathologically, the pancreatic head tumor invaded the main pancreatic duct (MPD) and CBD with extension into the CBD in a form of tumor cast. The tumor cells consisted of a solid proliferation with abundant eosinophilic cytoplasm and round nuclei in an acinar and trabecular fashion. A 55-year-old man with upper abdominal pain and nausea, had a cystic lesion approximately 3 cm in size in the pancreatic tail on CT. Histopathologically, the tumor was encapsulated by fibrous capsule and had extensive central necrosis with solid areas in the tumor periphery, and invaded with extension into the MPD in a form of tumor cast. The tumor cells resembled acinar cells in solid growths. Two resected cases of ACC with unusual tumor extension into the CBD and the MPD, respectively, are reported.     

Large solitary fibrous tumor of the oral cavity—Report of a case

The solitary fibrous tumor (SFT) is a rare soft tissue tumor with a substantially benign clinical behavior. The SFT of the oral cavity is a very uncommon entity. It is also of complicated diagnosis because of its extensive morphologic diversity and because of its similarity to many mesenchymal tumors. A 44-year-old man was referred for management of an asymptomatic lesion in the left buccal mucosa, which had been identified 10 years earlier. Intra-oral examination revealed a well-demarcated, fibroelastic, rounded exophytic mass located in the left buccal mucosa. The mass was covered with a non-ulcerated mucosa of normal color and measured approximately 4.0 cm in diameter. Histopathological examination showed proliferation of spindle-shaped cells arranged in fascicles and in a patternless pattern, highly vascularized, with focal staghorn vessels. Immunohistochemical analysis revealed diffuse positivity for CD34 and focal positivity for Bcl-2. Awareness of the morphological diversity of SFT coupled to a judicious use of appropriate immunohistochemical probes should prove valuable to accurately segregate SFT from other spindle cell neoplasms.     

伴有破骨细胞样巨细胞的胰腺未分化癌1例报道及文献复习

目的：探讨伴有破骨细胞样巨细胞的胰腺未分化癌的临床病理特点.方法：观察1例伴有破骨细胞样巨细胞的胰腺未分化癌的形态学特征,并进行免疫组织化学染色.结果：伴有破骨细胞样巨细胞的胰腺未分化癌肿瘤主要有两种细胞组成,一种为单核细胞,分为组织细胞样单核细胞和梭形或多形性瘤细胞两型;另一种为多核巨细胞,分为非肿瘤性的破骨细胞样巨细胞和瘤巨细胞两型.免疫组织化学研究显示,这两种细胞Vimentin均阳性,均不表达cytokeratin（AE1/AE3）,CK5/6,CEA,CgA;其中破骨细胞样巨细胞、组织细胞样单核细胞CD45,CD68阳性,而瘤巨细胞和梭形瘤细胞阴性.结论：伴有破骨细胞样巨细胞的胰腺未分化癌是一种罕见恶性肿瘤,可能为胰腺未分化癌的一个亚型.诊断需与胰腺恶性纤维组织细胞瘤、转移的骨巨细胞瘤或黑色素瘤等鉴别.     

Fat-forming solitary fibrous tumor of the kidney: a case report and literature review

Fat-forming solitary fibrous tumor (SFT) is a rare soft tissue tumor. Herein, we reported a 30-year-old woman was found to have a solid mass measuring 60×45 mm in the right kidney on an abdominal computed tomography scan. The tumor was well-circumscribed and composed of cellular nodules with the classic SFT admixed with clusters and lobules of mature adipocytes. Immunohistochemistry staining showed that the tumor cells were diffusely and strongly positive for CD34 and Bcl-2, focally and weakly positive for CD99 and EMA. Mature adipocytes were positive for S-100 protein. Ki-67 expression was found in approximately 2% of tumor cells. However, tumor cells were negative for cytokeratin, S-100 protein, HMB-45, Melan-A, SMA, and CD117. We made the pathological diagnosis of fat-forming SFT of the right kidney. The differential diagnosis includes angiomyolipoma, liposarcoma, spindle cell lipoma, sarcomatoid renal cell carcinoma, synovial sarcoma, and gastrointestinal stromal tumor. The patient was alive and well without evidence of recurrence or metastasis at 19 months after tumor resection.     

Solitary fibrous tumor of the kidney. Case report

Solitary fibrous tumors are rare spindle cell neoplasms usually arising in the pleura. They have, however, also been reported at extrapleural locations. Solitary fibrous tumor (SFT) of the kidney is rare. Despite its rarity, histological diagnosis of solitary fibrous tumor is crucial to avoid misdiagnosis with other more aggressive tumors arising in the kidney. We report a solitary fibrous tumor of the left kidney that presented as a malignant tumor in a 51-year-old woman, and include clinical and radiographic findings. The tumor was well circumscribed and composed of spindle cells in a collagenous stroma. Immunohistochemistry showed reactivity for vimentin, CD 34, BCL-2 protein and CD99. Immunohistochemical stains for cytokeratin, S-100, desmin, alpha-smooth muscle actin and HMB-45 were negative. A diagnosis of SFT was made based on light microscopy and immunohistochemistry.     

Neural fibrolipoma of the superficial peroneal nerve in the ankle: a case report with immunohistochemical analysis

This report presents a case of neural fibrolipoma arising from the superficial peroneal nerve in the ankle. A 28-year-old woman was referred with a soft tissue mass in the anterior aspect of the right ankle, which had been gradually enlarging for the past 10 years. Magnetic resonance imaging showed a mass lesion, measuring approximately 8 x 3 x 2 cm, with high to partially low signal intensity on both T1- and T2-weighted images. A band of low signal intensity within the lesion, which is indicative of coexistence with the tumor and the superficial peroneal nerve, could be detected on both T1- and T2-weighted images. The patient underwent an excisional biopsy. The specimen microscopically consisted of nerve bundles and fibro-fatty proliferation with abundant collagen fibers. Immunoreactivity for CD34 antigen antibody was detected in fibrous spindle cells. This is the first report to present an immunohistochemical profile of neural fibrolipoma. Neural fibrolipoma should be considered as a differential diagnosis when a lipomatous lesion is encountered in the foot or ankle as well as in the upper extremities.     

Lipoma-like tumor mass probably arising in the retroperitoneal heterotopic pancreas: a previously undescribed lesion

Heterotopic pancreatic tissue is found in several locations of the body. However, to the best of our knowledge, there have been no reports on heterotopic pancreas in the retroperitoneum. A case of retroperitoneal lipoma-like large tumor mass probably arising in the heterotopic pancreas is reported. A 45-year-old Japanese woman was admitted to hospital because of back pain. Imaging modalities showed an abnormal mass in the retroperitoneum separate from the surrounding organs, including the pancreas and kidney. Histologically, the mass consisted of mature adipose tissue and scattered ductal and acinar elements. Although there was no islet tissue in this fatty mass, the epithelial elements suggested heterotopic pancreatic tissue in origin. The present case is very unusual; however, heterotopic pancreas should be considered in the differential diagnosis of retroperitoneal tumors.     

Solid and Cystic Tumor of the Pancreas in an Adult Male

A solid and cystic tumor (SCT) was located at the head of the pancreas in a 43-year-old Japanese male, and pancreatoduodenectomy was performed on the suspicion of papillary carcinoma or cystadenocarcinoma of the pancreas. The lesion, which measured 4.5 X 4.5 X 4.0 cm, was clearly demarcated by connective tissue. The cut surface showed solid grayish-white areas with central cystic degenerative changes. The solid areas consisted of small round cells proliferating in a small solid or a pseudopapillary pattern. The tumor cells partially invaded the surrounding normal pancreatic parenchyma. Immunohistochemical studies revealed positive staining for alpha-1-antitrypsin and neuron-specific enolase, but no staining for known pancreatic hormones. Moreover, ultrastructural studies showed the absence of zymogen granules and the presence of anullate lamellae and neurosecretory granules. On the basis of these findings, a diagnosis of SCT of the pancreas was established. In order to clarify the histogenesis and biological behavior of the tumor, it is necessary to accumulate and analyze similar cases, an endeavor which in turn will contribute to the successful management of this disease. Acta Pathol Jpn 41: 763-770, 1991.     

Solitary fibrous tumor of the pancreas: a case report

Solitary fibrous tumor (SFT) is an unusual mesenchymal neoplasm that most often arises in the pleura; however, it has recently been described in a number of extrapleural sites. This report describes an extremely rare case of a benign SFT arising in the pancreas. A 41-year-old woman presented in the clinic with right upper abdominal pain. Subsequent ultrasonographic studies revealed a 1.5x1.5x1.4 cm hypoechoic mass within the pancreatic body, which was later confirmed on both helical computerized tomography and magnetic resonance imaging studies. An endocrine tumor was clinically suspected. Laparoscopic enucleation of the mass was performed. Microscopically, the tumor was composed of bland uniform spindle cells arranged between collagen bundles. On immunohistochemical studies, these spindle cells were positive for CD34 and bcl-2 but negative for cytokeratin (AE1+AE3 and Cam5.2), smooth muscle actin, desmin, S-100, and c-kit. Based on the light microscopic morphology and immunohistochemical staining profile, the diagnosis of SFT was rendered.     

F-18 FDG hypermetabolism in mass-forming focal pancreatitis and old hepatic schistosomiasis with granulomatous inflammation misdiagnosed by PET/CT imaging

Purpose: We report the case of a 59-year-old male patient who presented with space-occupying lesions in the pancreas and liver suggestive of metastatic pancreatic cancer. Materials and methods: Whole-body F-18 fluorodeoxyglucose (FDG) PET/CT imaging and enhanced CT imaging of the lesions were performed in addition to abdominal ultrasound, ERCP, and MRCP. Tumor markers, including CA199 and AFP, were also evaluated. Results: PET/CT imaging showed a soft tissue mass with indistinct boundaries in the head of the pancreas with a maximum SUV of 4.39. A less dense shadow was also found in the left lobe of the liver with an indistinct boundary and a maximum SUV of 4.13. Enhanced CT revealed an enhancing mass in the head of the pancreas on arterial phase imaging as well as a mildly enhancing focus in the left lobe of the liver. The patient was diagnosed with a space-occupying lesion of the uncinate process of the pancreas suggestive of pancreatic cancer with metastasis to the liver. However, serum tumor markers were normal. Postoperative pathology was consistent with chronic pancreatitis and old hepatic schistosomiasis associated with granulomatous inflammation of the liver. Conclusion: This case of mass-forming pancreatitis and granulomatous inflammation in old hepatic schistosomiasis mimicked metastatic pancreatic cancer on PET/CT. Such false positive lesions have not been reported before, and further exploration and investigation are needed.     

Calcifying fibrous tumor of the adrenal gland

Calcifying fibrous tumor is an uncommon entity with distinctive pathologic features. Most calcifying fibrous tumors involve the peripheral soft tissues or serosal surfaces, with reports of visceral examples of this lesion being extremely limited. We report the clinical and pathologic features of an unusual case of calcifying fibrous tumor occurring in the adrenal gland of a 32-year-old woman. Microscopically, the lesion was well circumscribed and composed of dense, poorly cellular collagenous tissue, scattered spindle cells, an inflammatory infiltrate consisting of plasma cells and lymphocytes, and dystrophic calcifications. The morphologic diagnosis of calcifying fibrous tumor was supported by diffuse positive immunoreactivity for factor XIIIa and absence of reactivity for muscle specific actin, smooth muscle actin, and anaplastic lymphoma kinase. Although rare, awareness that calcifying fibrous tumor may occur at this particular site is important so as not to confuse this lesion with other mesenchymal neoplasms of the adrenal gland.     

Multicystic pancreatic hamartoma: a distinctive lesion with immunohistochemical and ultrastructural study.

A multicystic pancreatic hamartoma is reported in a 20-month-old female who presented with abdominal pain and distention. This appears to be a distinctive lesion not previously characterized in the English language literature. The 9-cm mass consisted of large, irregular lobules of well-formed pancreatic acini admixed with fibrous tissue and fat. Cystically dilated ducts of variable caliber lined by benign epithelium were present. Endocrine cell islets were not evident. Immunohistochemistry and ultrastructural examination illustrated insulin-producing cells diffusely throughout the exocrine tissue as single cells or in small groups. Cells producing other pancreatic hormones were markedly decreased when compared with an age-matched control pancreas and were similarly dispersed. The patient was alive and well without tumor 9 months later. This entity may provide an unusual opportunity for insight into pancreatic organogenesis and pancreatic cellular differentiation.     

First case of primary phyllodes tumor of the pancreas: case report and findings of immunohistochemical and ultrastructural studies

A 37-year-old Japanese man with a solid and cystic pancreatic mass was referred to our hospital. Computed tomography revealed a well-demarcated solid and cystic mass measuring approximately 3.0 cm in diameter in the pancreatic body. The patient underwent middle segment pancreatectomy, and the retrieved tumor specimen was found to be a well-demarcated solid and cystic lesion measuring 3.0 × 3.0 cm. On histological examination, the cyst walls were found to be lined with a monolayer of non-atypical tall columnar epithelial cells. The solid areas surrounded the cystic ones and showed storiform proliferation of spindle cells that contained round, oval, or elongated nuclei and were present among abundant collagen fibers. The solid areas sent phylloid projections into the cystic spaces and the main pancreatic duct. The spindle cells were found to be diffusely positive for alpha-smooth muscle actin, desmin, and h-caldesmon on immunohistochemical analysis. Electron microscopy revealed that these cells possessed well-developed myofilaments with dense bodies, pinocytic vesicles, and basal lumina. Neither metastasis nor local invasion was detected. After the operation (4 years), tumor recurrence has not occurred. The main differential diagnoses of spindle cell tumors are leiomyomas, leiomyosarcomas, inflammatory myofibroblastic tumors, solitary fibrous tumors, extra-gastrointestinal stromal tumors, and schwannomas. However, the histological findings in the present case differed from those of these tumors. The present lesion is the first reported case of a primary pancreatic phyllodes tumor.     

Solid pseudopapillary tumor of the pancreas with metastases to the lung and liver

Presented herein is the case of a 41-year-old woman who was admitted to Teikyo University Hospital with abdominal and back pain. Clinical examination revealed a large mass of the pancreas and multiple nodules in the liver. After surgical resection of the pancreatic and liver tumors, liver nodules recurred repeatedly, and a solitary mass lesion occurred in the right lung. Grossly, the pancreatic tumor was large and partially cystic. Histologically, small and uniform tumor cells proliferated, having solid and pseudopapillary patterns. These pathological findings enabled a pathological diagnosis of solid pseudopapillary tumor (SPT) of the pancreas to be made. The pathological appearance of the liver and lung tumors was similar to that of the pancreatic tumor. This is the first report of a case of pancreatic SPT that showed lung metastasis. It should be kept in mind that pancreatic SPT may take such an aggressive clinical course, although they are usually benign in nature.     

STAT6 expression in spindle cell lesions of the breast: An immunohistochemical study of 48 cases

The diagnosis of spindle cell lesions of the breast parenchyma is challenging. Some of these lesions share the expression of CD34, posing differential diagnostic problems, especially in core biopsies. Recently, antibodies against the STAT6 C-terminal, are being used in paraffin-embedded tissues as a surrogate for identifying the NAB2–STA6 fusion gene which is considered a specific molecular marker for solitary fibrous tumor. Accordingly, we investigated the expression of STAT6 in a large series of uncommon spindle cell tumor-like and tumor lesions occurring primarily in the breast parenchyma. We collected 10 classic-type myofibroblastomas, 9 desmoid-type fibromatosis, 6 spindle cell metaplastic carcinoma, 5 benign fibroblastic spindle cell tumors, 3 solitary fibrous tumors, 7 pseudoangiomatous stromal hyperplasias, 2 reactive spindle cell nodules, 1 leiomyoma, 1 spindle cell lipoma, 1 case of inflammatory pseudotumor, 1 nodular fasciitis, 1 myxoma and 1 dermatofibrosarcoma protuberans. A diffuse and strong nuclear STAT6 expression was restricted only to solitary fibrous tumors, while the other lesions were negative or showed only weak cytoplasmic expression. The present study confirms that the demonstration of a diffuse and strong STAT6 nuclear staining is very helpful in distinguishing solitary fibrous tumor from other spindle cell mimics arising in the breast.     

A spindle cell predominant pancreatic solid-pseudopapillary tumor

A hitherto unrecognized variant of solid-pseudopapillary tumor (SPT) of the pancreas is reported. The tumor presented in the pancreatic tail of a 44-year-old female patient. It was a well-defined, solid nodule measuring 25 mm in diameter, with homogenous tan gray cut surface. Histologically, the neoplasm was mostly composed of sheets of spindle cells. No cellular atypia and mitosis was identified. The periphery of the tumor showed typical feature of SPT. Immunohistochemically, the tumor cells were positive for vimentin, CD10, CD56, beta-catenin, and alpha1-antichymotrypsin, but negative for cytokeratin, chromogranin, synaptophysin and S-100 protein. Ultrastructurally, the tumor showed a few acinar spaces with microvilli between tumor cells. This case is peculiar in that the tumor did not show gross cystic change and predominantly consists of spindle shaped tumor cells, so may cause difficult diagnostic problem.