Benign solitary fibrous tumor of the pancreas: a rare location of extra-pleural fibrous tumor. Single case report and review of the literature

BACKGROUND/AIMS: Extra pleural solitary fibrous are very rare, but occasionally they appear in extraserosal soft tissues or parenchymatous organs, where their diagnosis is often a challenge. In this report we describe the case of a patient with a single primary solitary fibrous tumor of the pancreatic head with a review of the literature. METHODS/RESULTS: A 62 years old woman underwent a Traverso-Longmire procedure in November 2004. Sixteen months after resection there is no evidence of recurrence. The tumour showed immunoreactivity for CD34, CD99, bcl-2, vimentin and smooth muscle actin. MIB-1 proliferating activity was < 5%. CONCLUSIONS: Extra pleural solitary fibrous tumor are often benign lesions. In the pancreas only 2 cases have been described so far. Other mesenchymal tumours that may occur in the pancreas include leiomyosarcoma, tumours of the peripheral nerve sheath, fibrous histiocytic tumours and rare vascular tumours. The differential diagnosis is mainly based on immunohistochemistry. The surgical approach is fundamental for the treatment of solitary fibrous tumour.     

Pleomorphic leiomyosarcoma of the adrenal gland

Primary leiomyosarcomas arising in the adrenal gland are exceedingly rare, with only 3 cases reported in the literature. We present the clinical, morphologic, and immunohistochemical features of a pleomorphic leiomyosarcoma, a variant of leiomyosarcoma that has not been described in the adrenal gland. A 63-year-old man presented with a 1-year history of enlarging right upper quadrant mass and pulmonary nodule. A diagnosis of metastatic pulmonary carcinoma to the adrenal gland was rendered on a needle biopsy specimen. Preoperative chemotherapy reduced only the pulmonary mass but not the adrenal mass, which continued to enlarge. Documented by computed tomography and confirmed at surgery, the tumor had completely replaced the right adrenal gland, invading into both the posterior aspect of the right liver and the superior pole of the right kidney. Histologic sections showed a diffuse proliferation of pleomorphic, large, and polygonal neoplastic cells with prominent nucleoli. Many bizarre mitotic figures were present. The neoplastic cells were strongly positive for desmin, calponin, and vimentin. Approximately 80% of the neoplastic cells were positive for the proliferation marker Ki-67. They were negative for smooth muscle actin, muscle-specific actin, myoglobin, myogenin, CD117, cytokeratins, carcinoembryonic antigen, epithelial membrane antigen, chromogranin, CD34, CD31, S100 protein, and HMB-45.     

Stromal sarcoma of the breast with leiomyosarcomatous pattern

We report an unusual case of stromal sarcoma of the breast with leiomyosarcomatous pattern, which recurred locally and was finally treated by radical mastectomy. The tumor was composed of pleomorphic and hyperchromatic spindle-shaped cells arranged in an interdigitating fascicle. The nuclei were of moderate to severe atypia. An average of 10 mitoses per 10 high-power fields was seen. Immunohistochemically, the stromal cells were positive for vimentin and alpha-smooth muscle actin, but negative for S-100 protein, cytokeratin and desmin. The average Ki-67 (MIB1) labeling index in the stromal cells was 34%. Electron microscopic evaluation revealed further evidence of smooth muscle differentiation; stromal cells had frequently indented nuclei, well-developed rough endoplasmic reticulum, thin basal lamina and dense patch-like structures within the cytoplasm. Analysis of previous literature on 17 cases reveals mitotic activity of the tumor seemingly of little prognostic value. This case indicated difficulty in diagnosing leiomyosarcoma. The risk of local recurrence remains even if the surgical margin is free of tumor cells.     

Pleomorphic rhabdomyosarcoma in adults: immunohistochemistry as a tool for its diagnosis

Pleomorphic rhabdomyosarcoma in adults over 30 years of age was a diagnosis frequently made in the 1960s and 1970s. Since the general acceptance of malignant fibrous histiocytoma (MFH) as a tumor entity at the end of the 1970s, however, it has become a very rare tumor in adults. Therefore, 21 cases originally diagnosed on the basis of histology and clinical data as pleomorphic rhabdomyosarcoma in the 1960s and 1970s were reexamined immunohistochemically. Other types of pleomorphic sarcomas involved in the differential diagnosis were also studied. Specific antibodies against vimentin, desmin, creatine kinase subunit M, skeletal muscle actin and myosin, and myoglobin, and the avidin-biotin-peroxidase complex technique were used. The immunohistochemical findings indicate that rhabdomyosarcoma occurs only rarely in adults over 30 years of age and that the majority of the tumors have to be reclassified as MFH or leiomyosarcoma. On the other hand, several pleomorphic sarcomas were found to be diagnosed incorrectly as MFH or liposarcoma by routine histologic stains and electron microscopy. The revised diagnosis was pleomorphic rhabdomyosarcoma for one case and pleomorphic leiomyosarcoma for the other cases. Thus, this study clearly shows the usefulness of immunohistochemistry as a technique in the diagnosis of pleomorphic sarcomas in adults.     

Giant cell tumor of the pancreas of mixed osteoclastic and pleomorphic cell type: evidence for a histogenetic relationship and mesenchymal differentiation

We describe a giant cell tumor of the pancreas composed of a mixture of osteoclastic and pleomorphic cell types. This rare tumor had a unique immunohistochemical profile. Both types of tumor giant cells stained for vimentin, alpha-1-antitrypsin, alpha-1-antichymotrypsin, synaptophysin, muscle actin, and neuron-specific enolase, but not for epithelial markers. Electron microscopy showed cells which resembled primitive fibroblasts and osteoclast with no epithelial features. These findings are most consistent with mesenchymal differentiation. The extensive homologies in immunohistochemical staining of both osteoclastic and pleomorphic giant cells in this case indicates that these cells are histogenetically related.     

Leiomyosarcoma of the pulmonary vein

A case of a 74-year-old man with leiomyosarcoma of the pulmonary vein is reported. The patient felt transient chest oppression while playing golf 1 week before he visited a clinic with a common cold. He underwent an ultrasonographic examination of the heart, which showed a mass lesion in the left atrium. The preoperative clinical diagnosis was myxoma of the left atrium. Cardiac surgery revealed the mass to be a leiomyosarcoma, probably extending from the left inferior pulmonary vein. The patient underwent a left lower lobectomy of the lung, and the tumor was confirmed to have originated from the wall of the left inferior pulmonary vein. Although the patient had a metastatic lesion in the right axillary lymph node 11 months later, which was excised, he remained free of disease 14 months after the initial operation. Histologically, the tumors were composed of pleomorphic cells with bizarre nuclei and spindle cells with blunt-ended nuclei with 1-4 mitotic figures in 10 high power fields. Immunohistologically, the tumor cells were positive for alpha-smooth muscle actin and desmin. We reviewed 17 cases of leiomyosarcoma of the pulmonary vein (six males and 11 females with a mean age of 50 years in each group). The present case was the oldest in age and to our knowledge was the first reported case with metastasis in a distant lymph node.     

Primary desmoplastic cutaneous leiomyosarcoma associated with high MIB-1 labeling index: a teaching case giving rise to diagnostic difficulties on a small biopsy specimen

A case of primary desmoplastic cutaneous leiomyosarcoma is reported. A flat and elevated tan plaque, measuring 30 mm × 20 mm, was noticed in the left back of a 74-year-old Japanese male 6 months before the resection. The biopsy specimen showed an overgrowth of desmoplastic fibrocollagenous stroma, focally admixed with a less cellular proliferation of spindle cells having mildly pleomorphic nuclei, but no mitotic figures, arranged in small clusters or appearing as individual cells. Based on these features, we interpreted it as a benign keloid-like lesion. A local resection was done, and gross examination revealed a poorly demarcated grayish tumor lesion, replacing the entire dermis and extending into the subcutis. Microscopic findings demonstrated a sparsely cellular proliferation of atypical spindle cells having cigar-shaped or multi-nucleated pleomorphic nuclei and abundant eosinophilic cytoplasm with few mitotic hot spots, arranged in interlacing bundles, alternating with scattered tumor cells within an abundant desmoplastic stroma. Immunohistochemically, these atypical cells were positive for α-smooth muscle actin, HHF-35, desmin, and caldesmon, and MIB-1 labeling index was greater than 10%. Therefore, we finally made a diagnosis of desmoplastic leiomyosarcoma as a very rare variant of cutaneous leiomyosarcoma. We should be aware that owing to its characteristic features, pathologists might misinterpret it as benign when examining only small or inadequate specimens. It is thus suggested that a large panel of antibodies including smooth muscle cell markers and MIB-1 in immunohistochemistry are useful and adjunctive diagnostic aids for recognizing malignancy, especially in diagnostically difficult cases such as ours.     

Subcutaneous leiomyosarcoma in an adrenomedullin heterozygous mouse

The present study reports a case of a 5-month-old female adrenomedullin (AM) heterozygous (+/?) mouse that presented a mass of leiomyosarcoma found in the right shoulder girdle region. The neoplastic mass extended to the sternal region and showed hemorrhages, congestion and necrotic foci. The excised tumor with a diameter of 2.5 cm was firm, ill-demarcated and had focally infiltrated the surrounding muscles. The cut surface was homogeneously whitish with multi-focal reddish lesions. Microscopically, the tumor composed of variable fascicles of spindle-shaped cells with pleomorphic and cigar-shaped nuclei. The nuclei were round and elongated. Metastasis of tumor cell to skeletal muscle was frequently observed. Immunohistochemically, desmin, vimentin and α-smooth muscle actin (α-SMA) were demonstrated in neoplastic cells but tumor cells were negative for cytokeratin (CK) and S-100. Based on gross finding, microscopical examination and immunohistochemistry, the present case was diagnosed as a subcutaneous leiomyosarcoma.     

Fatty replacement of the pancreatic body and tail associated with leiomyosarcoma of the pancreatic head

A case of fatty replacement of the pancreatic body and tall associated with leiomyosarcoma of the pancreatic head is presented. Clinicopathological features as well as differential diagnoses are described with a review of the literature on both leiomyosarcoma and fatty replacement of the pancreas. A possible correlation between the two lesions is also discussed.     

Ovarian leiomyosarcoma: an autopsy case report

Primary non-specific sarcoma of the ovary is extremely rare, and only 22 reported cases of pure leiomyosarcoma (LMS) are known to the authors. We present an autopsy case of a primary ovarian leiomyosarcoma in a 73-year-old woman. She had noticed an abdominal mass after difficulty in defecating for several months. The excision of tumor with bilateral salpingo-oophorectomy and hysterectomy was carried out. A diagnosis of pure leiomyosarcoma of the left ovary was made on pathological examination with immunohistochemistry. Adjuvant radio-chemotherapy was not given. At 18 months' follow up, abdomino-pelvic sonography revealed an abdominal tumor and hepatic metastasis. The patient died 3.5 years after the initial surgery. The post-mortem examination revealed a peritoneal recurrent tumor and extensive distant metastases of the liver, lungs, pancreas, gastric mucosa, muscle and skin. The prognosis of the ovarian LMS is poor from the pertinent literature. Several prognostic indicators on histology including mitotic activity, proliferative activity and p53 status of the tumor are discussed.     

An unusual clinical presentation of a rare tumor of the thyroid gland: report on one case of leiomyosarcoma and review of literature

Primary muscle tumors of the thyroid gland are exceedingly rare. We report on the case of a patient with primary leiomyosarcoma of the thyroid gland and review the literature. An 83-year-old woman complaining of neuropathic pain in her left arm and enlargement of her anterior neck underwent multiple surgical biopsies of the thyroid gland. The tumor was composed of interlacing fascicles of spindle-shaped cells that expressed smooth muscle actin and vimentin but were negative for cytokeratins and thyroglobulin. Ultrastructurally, bundles of myofilaments were present. Magnetic resonance imaging showed a thyroid tumor that directly extended to the adjacent vertebra with an associated pachymeningitis. The patient died 2 months after surgery. The diagnosis of primary leiomyosarcoma of the thyroid gland is difficult and requires numerous clinical, radiologic, and pathologic data. To our knowledge, this case is the first one with such a locoregional extension.     

Rhabdoid features in leiomyosarcoma of soft tissue: with special reference to aggressive behavior.

The presence of rhabdoid cells has been reported in various types of malignant neoplasms and has been determined to be a predictor of aggressive behavior of neoplasms regardless of tumor histogenesis. One hundred and thirteen cases of leiomyosarcoma, selected from 1800 soft tissue sarcomas, were reviewed on hematoxylin and eosin sections, and immunohistochemical staining when available, and seven cases with rhabdoid features were retrieved. Clinicopathologic differences were analyzed to compare between cases with rhabdoid features and those without rhabdoid features. In the seven cases with rhabdoid features, two were intra-abdominal, and the others arose in external soft tissues including muscle, subcutis, and cutis. Patient age ranged from 33 to 84 years, three were female, and four were male. Tumor size ranged from 3 to 22 cm. Clinical evidence showed no differences from those cases without rhabdoid features. Histologically, one of the abdominal cases was epithelioid leiomyosarcoma. Two of the 7 cases were better subclassified as pleomorphic leiomyosarcoma, in which rhabdoid cells are diffusely scattered. In cases other than those with pleomorphic leiomyosarcomas, foci of anaplastic areas were observed, and collections of rhabdoid cells were present in those areas. Immunohistochemical examination of the cases confirmed myogenic differentiation, and showed rhabdoid cells being positive for vimentin and desmin in the inclusion bodies, and diffusely so for muscle actin in the cytoplasm. After dividing all the cases of leiomyosarcoma by their location, prognostic analysis was performed. Leiomyosarcoma of external soft tissue with rhabdoid cells showed a tendency for poorer prognoses than cases without rhabdoid features. On the contrary, retroperitoneal cases did not. This study indicates that rhabdoid features are associated with aggressive biological behavior in leiomyosarcoma of the external soft tissue.     

Pleomorphic epithelioid/clear cell malignant tumor of the uterus exhibiting both myoid and melanocytic differentiation--leiomyosarcoma or PEComa? A case report and a review of the literature

30-year-old woman admitted for acute abdominal pain with peritoneal signs was immediately operated with findings of hemorrhage in small pelvis. Laparotomy revealed hemorrhagic, friable mass 3 cm in maximum diammeter arising from the uterine horn. The neoplasm broadly invaded myometrium with no evidence of endometrial cavity involvement. Microscopically, the tumor displayed solid mosaic pattern and consisted of large epithelioid cells with ample eosinophilic, finely granular cytoplasm ongoing apparent clear cell change elsewhere. There was marked nuclear irregularity with numerous atypical mitotic figures and multiple bizarre giant elements dispersed throughout the lesion. Unusual complex phenotype included co-expression of vimentin, smooth muscle actin, desmin, HMB45, Melan A, CD10 and EMA. No obvious stigmata of tuberous sclerosis were found and a five months follow-up after chemotherapy indicated no progression of disease. With some uncertainty the tumor was finally rendered as pleomorphic leiomyosarcoma with peculiar melanocytic differentiation. PEComa as an alternative term was coined. Expressed are both difficulty in explaining the histogenesis and ambiguity of the existing terminology of the uterine tumors with mixed myoid and melanocytic phenotype. Reviewed is the literature and discussed is the differential diagnosis.     

Leiomyosarcoma of the pancreas

We report a case of leiomyosarcoma of the pancreas. A spindle cell pattern at light microscopy, immunocytochemical reactivity with desmin, alpha-1-antitrypsin, vimentin and actin and ultrastructural features of smooth muscle differentiation help to establish the diagnosis.     

Epithelioid leiomyosarcoma of the external deep soft tissue

Epithelioid leiomyosarcoma in the external deep soft tissue is extremely rare. Most epithelioid leiomyosarcomas occur in the uterus. We present a case of epithelioid leiomyosarcoma occurring in the muscle of the thigh of a 78-year-old man. Histologically, the tumor predominantly consisted of round or polygonal cells arranged in sheets with a focal spindle cell component. Immunohistochemical analysis revealed that the tumor cells expressed vimentin, alpha-smooth muscle actin, and alpha-sarcomeric actin. The tumor was negative for desmin, S100 protein, glial fibrillary acidic protein, pan-keratin, epithelial membrane antigen, CAM 5.2, HMB-45, leukocyte common antigen, factor VIII-associated antigen, and CD34. Electron microscopically, some tumor cells contained abundant actin-type filaments in their cytoplasm.     

Metastatic pulmonary leiomyosarcoma: Cytopathologic diagnosis on sputum examination

Pulmonary metastasis of sarcomas is not uncommon. Rarely, endobronchial involvement may result in exfoliation of diagnostic cells in sputum. This case report is of a 71-yr-old man with a history of lower leg leiomyosarcoma who developed multiple lung metastases. Sputum examination revealed malignant cells with pleomorphic, elongated, and cigar-shaped nuclei and occasional bipolar cytoplasmic processes. Immunoperoxidase studies on the smears using desmin and smooth muscle actin were strongly positive, consistent with leiomyosarcoma. Confirmation of metastatic lung disease by sputum cytology not only has prognostic importance but also obviates the need for further investigations. Diagn. Cytopathol. 1998;18:280–283. © 1998 Wiley-Liss, Inc.     

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.     

Calponin and h-caldesmon expression in atypical fibroxanthoma and superficial leiomyosarcoma

To evaluate smooth muscle differentiation, myogenic markers [desmin, alpha-smooth muscle actin (SMA), and muscle-specific actin (HHF35)] have been widely used. Calponin and h-caldesmon, which are cytoskeleton-associated actin-binding proteins, have been reported to be more specific myogenic markers, especially since myofibroblasts express a small amount of h-caldesmon. Atypical fibroxanthoma (AFX) occurs in the sun-exposed skin of the elderly and follows a benign clinical course. Histologically, AFX, which is a pleomorphic spindle cell tumor and considered to be a superficial variant of malignant fibrous histiocytoma, also mimics leiomyosarcoma. AFX has been thought to differentiate along pathways with fibrohistiocytic and myofibroblastic phenotypes. AFX ( n=10), superficial leiomyosarcoma (S-LMS) ( n=17) and benign fibrous histiocytoma (BFH) ( n=17) were analyzed for myofibroblastic and smooth muscle differentiation immunohistochemically from the viewpoint of comparison. AFX and BFH showed immunoreactivities respectively for calponin (3/10, 11/17), desmin (3/10, 1/17), SMA (3/10, 13/17), and HHF35 (1/10, 5/17), but failed to express h-caldesmon (0/10, 0/17). S-LMS had a high immunoreactive rate of calponin (17/17), desmin (13/17), SMA (16/17), and HHF35 (16/17), while also expressing caldesmon (11/17). The results reveal that AFX and BFH have immunoreactivities for several myogenic markers, with myofibroblastic differentiation (calponin: +/-, h-caldesmon: -), but without the smooth muscle differentiation seen in S-LMS (calponin:+, h-caldesmon: +/-). In addition, calponin and h-caldesmon are considered to be useful markers for distinguishing AFX from S-LMS.     

Immunohistochemical and immunoblotting detection of cytokeratin in smooth muscle tumors.

Forty-six smooth muscle tumors, including 35 of gastrointestinal origin, were studied immunohistochemically for the localization of cytokeratin using a variety of monoclonal antibodies. In formalin-fixed, paraffin-embedded material, six of 40 leiomyomas, two of five leiomyosarcomas and one leiomyoblastoma were immunoreactive for cytokeratin in a few tumor cells. A proportion of non-neoplastic smooth muscle cells also exhibited a positive reaction. In fresh frozen sections of one gastric leiomyosarcoma, a high percentage of tumor cells were reactive with nine of the eleven anti-cytokeratin monoclonal antibodies examined. Cytokeratin-positive cytoplasmic filaments were further demonstrated by immunoelectron microscopy. By immunoblot analysis, an extract of this immunohistochemically cytokeratin-positive leiomyosarcoma showed a distinct band at the same position as an extract of pancreas, whereas no bands were seen in an extract of a cytokeratin-negative esophageal leiomyosarcoma. These immunohistochemical and immunoblotting findings indicate that a certain subset of smooth muscle neoplasms express genuine cytokeratin filaments.     

Neuron-specific enolase-producing leiomyosarcoma of the mesentery

A case of neuron-specific enolase (NSE)-producing leiomyosarcoma arising in the mesentery of a 62-year-old female is presented. Preoperatively, serum level of NSE was markedly elevated. A well-defined but unencapsulated tumor measuring 14 x 12 x 9 cm was histologically characterized by a fascicular or herring-bone arrangement of atypical spindle or oval tumor cells with vesicular cigar-shaped nuclei, inconspicuous nucleoli and abundant clear to brightly eosinophilic cytoplasm. Immunohistochemically, the tumor was positive for vimentin, alpha-smooth muscle actin, muscle actin, desmin, and gamma-NSE. Postoperatively, serum level of NSE decreased to within normal range. The NSE levels were, however, elevated again as metastatic lesions in the liver had enlarged. The patient died of the liver metastases 10 months after surgery. Serum NSE level can be a useful index of tumor extent and for monitoring treatment of some patients with leiomyosarcoma.