Plexiform Fibromyxoma in the Stomach: Immunohistochemical Profile and Comprehensive Genetic Characterization

Plexiform fibromyxoma (PF), also referred to as plexiform angiomyxoid myofibroblast tumor, is an exceedingly rare mesenchymal neoplasm primarily affecting the stomach. Herein, we present a case of PF diagnosed in a 71-year-old male with a history of lung cancer, initially suspected to have a gastrointestinal stromal tumor (GIST) of the stomach, who subsequently underwent subtotal gastrectomy. The histopathological and molecular features of the tumor, including mutations in ABL1, CCND1, CSF1R, FGFR4, KDR, and MALAT1-GLI1 fusion, are elucidated and discussed in the context of diagnostic, prognostic, and therapeutic considerations.

Primary pulmonary hyalinizing spindle cell tumor with giant rosettes: A clinicopathological and immunohistochemical study of 2 cases

Two cases of primary intrapulmonary hyalinizing spindle cell tumor with giant rosettes are presented. The patients are one woman and one man ages 37 and 42 years respectively. Both patients presented with non-specific symptoms of cough, dyspnea, and chest pain. Imaging revealed the presence of an intrapulmonary mass. One tumor was located in the left lower lobe while the other tumor was in the right upper lobe. Both patients underwent lobectomy. The tumors ranged from 2.4 to 3.0 cm in greatest dimension and were characterized by the presence of a bland spindle cell proliferation with areas of hyalinization and the presence of the so-called giant rosettes. Immunohistochemical stains were performed and the spindle cell component show positive staining for vimentin and negative staining for Bcl-2, CD34, STAT6, p40. Keratin immunohistochemical stain highlighted the entrapped alveolar epithelium while S-100 protein showed weak focal staining in the spindle cells. Both patients have remained alive and well without evidence of recurrence or metastasis for a period of 6 to 14 months post-surgical resection. The cases herein presented highlight the ubiquitous distribution of this tumor and underscores the importance of keeping this particular tumor in the differential diagnosis of spindle cell tumors of the lung.

Characterization of a novel CDC73 gene mutation in a hyperparathyrodism-jaw tumor patient affected by parathyroid carcinoma in the absence of somatic loss of heterozygosity

Hyperparathyrodism-jaw tumor (HPT-JT) syndrome is an autosomal dominant disorder. Loss of function of the cell division cycle protein 73 homolog (CDC73) gene is responsible for the syndrome. This gene encodes an ubiquitously expressed 531 amino acid protein, parafibromin, that acts as a tumor suppressor. Loss of heterozygosity (LOH) of the CDC73 locus in many HPT-JT associated parathyroid tumors from patients with germline mutation is in accordance with Knudson's "two-hit" model for hereditary cancer. A 41-year-old man with mandible ossifying fibroma suffered from severe hypercalcemia due to parathyroid carcinoma (PC). Genetic analysis was performed to evaluate germinal and somatic CDC73 gene mutation as well as real-time qRT-PCR to quantify CDC73 mRNA, miR-155 and miR-664 expression levels. Immunohistochemistry and Western blotting (WB) assay were carried out to evaluate parafibromin protein expression. A novel heterozygous nonsense mutation, c.191-192 delT, was identified in the CDC73 gene. No CDC73 LOH was found in PC tissue, nor any differences in expression levels for CDC73 gene, miR-155 and miR-664 between PC and parathyroid adenoma control tissues. On the contrary, both immunohistochemistry and WB assay showed an approximate 90% reduction of parafibromin protein expression in PC. In conclusion, this study describes a novel germinal mutation, c.191-192 delT, in the CDC73 gene. Despite normal CDC73 gene expression, we found a significant decrease in parafibromin. We hypothesize that a gene silencing mechanism, possibly induced by microRNA, could play a role in determining somatic post-transcriptional inactivation of the wild type CDC73 allele.

[Clinicopathologic features and immunophenotype of pseudosarcomatous myofibroblastic proliferation of urinary bladder]

Objective: To investigate the clinicopathologic features, immunohistochemical phenotypes and biological behavior of pseudosarcomatous myofibroblastic proliferation (PMP) of the urinary bladder which may be misdiagnosed as a malignant neoplasm and undergo extensive treatment. Methods: Six cases of PMP of the urinary bladder were collected from 2001 to 2016 at Beijing Tiantan Hospital, Capital Medical University. The clinicopathologic features and immunophenotypic profile were studied by histopathological and immunohistochemical investigations with clinical follow-up. At the same time, the translocation of ALK gene was detected by fluorescence in situ hybridization (FISH). Immunohistochemistry was carried out using EnVision method for the expression of AE1/AE3, vimentin, EMA, SMA, Caldesmon, Calponin, desmin, ALK, Ki-67, MyoD1, myoglobin, CD34, S-100, CD117, CK7, CK20, GATA3, p63 and CK5/6. The related literature was reviewed. Results: There were two male and four female patients, significantly more common in women. The age of the patients was 27 to 53 years, and the median age was 35 years. The main clinical symptom was painless gross hematuria, one case with dysuria, and one case showed recurrent cystitis. There was no history of surgery and trauma. Follow-up ranged from 4 months to 13 years and showed five cases without recurrence and one case with recurrence. Microscopy showed submucosal lesion with inflammatory exudate and bleeding on the surface, in some cases extending to the superficial muscles of the bladder wall. The lesion was characterized by the proliferation of plump spindle cells, which were loose or dense in arrangement. There were varying degrees of acute and chronic inflammatory cells infiltration in the myxoid matrix. Spindle cells arranged in disorder, or a dense stranding, especially abundant in the cell region. The median mitotic rate was <2/10 HPF cells, but there were no pathological mitotic figures and without nuclear atypia in most spindle cells. Spindle cells with eosinophilic cytoplasm showed long tapering cytoplasmic projections. Oval or short spindle nuclei had vacuolization with prominent nucleoli, looking like ganglionic cells. There were scarce collagen fibers, and a few spindle cells degenerated with chromatin blurred. Some areas showed a granuloma-like pattern and neutrophils within vascular cavity. Immunohistochemically, the spindle cells were diffusely positive for vimentin, SMA and caldesmon. CKpan was strongly and diffusely positive. Desmin and calponin expression was varying. Ki-67 positive cells were about 35% to 55%, but the spindle cells were negative for myoglobin, S-100, CD117, CD34, p63 and CK5/6. FISH test showed that there was no ALK isolated signal in 6 cases of PMP, and so no positive cases were found. Conclusions: PMP of the urinary bladder is a benign non-neoplastic myofibroblastic proliferative lesion. Morphology is extremely easy to be misdiagnosed as malignant tumors, and therefore more attention should be paid to avoid this misdiagnosis.

Ovarian fibroma/fibrothecoma with elevated serum CA125 level: A cohort of 66 cases

Ovarian fibroma/fibrothecoma with elevated serum OC125 antigen (CA125) is rarely encountered in clinical practice, and also easily misdiagnosed as epithelial ovarian carcinoma (EOC). The aim of this study was to investigate the clinicopathological features of ovarian fibroma/fibrothecoma with elevated serum CA125.In total, 580 patients who underwent primary surgery and pathologically diagnosed as ovarian fibroma/fibrothecoma were retrospectively analyzed. The clinicopathological parameters were collected and compared between the patients with elevated serum CA125 (>35 U/mL) and without. The immunoreactivity for CA125 in ovarian fibroma/fibrothecoma and epithelial cancer tissues was detected and compared by immunohistochemistry. Univariate and multivariate analyses were performed to identify factors associated with elevated serum CA125 level. The correlation between the immunoreactivity of CA125 in tissue and serum CA125 level was examined by Pearson correlation analysis.Elevated serum CA125 level (range 36.7-1848 u/m) was found in 66 of 580 (11.3%) ovarian fibroma/fibrothecoma patients. Univariate analysis showed that the elevated serum CA125 level was significantly correlated with tumor diameter ≥10 cm (P < .001), ascites (P < .001), and hydrothorax (P < .001). Multivariate analysis revealed that tumor diameter ≥10 cm and ascites were independently associated factors (P < .001 and < .001 respectively). Immunohistochemical staining showed that the expression of CA125 was negative in all fibroma/fibrothecoma tissues, but positive in all EOC tissues, and the immunoreactivity for CA125 was positively correlated with serum CA125 level in the EOC patients (P = .005).The elevated serum CA125 level in ovarian fibroma/fibrothecoma is nontumor originated and occurs more frequently in those with larger size tumor or Meigs syndrome.

Activation of the LKB1‑SIK1 signaling pathway inhibits the TGF‑β‑mediated epithelial‑mesenchymal transition and apoptosis resistance of ovarian carcinoma cells

Ovarian cancer is the most common and lethal type of gynecological malignancy, due to its invasiveness. The present study aimed to analyze the molecular mechanism underlying chemoresistance in ovarian carcinoma cells, which may lead to local migration toward adjacent tissues and long‑distance metastasis to other organs. A total of 12 patients with ovarian fibroma were used to evaluate chemoresistance and chemosensitivity. The sensitivity and resistance of ovarian carcinoma cells was measured using apoptosis analysis, morphological observation, survival rate analysis, immunohistochemistry and immunostaining. The mechanism underlying the interaction between the epithelial‑mesenchymal transition (EMT) and liver kinase B1 (LKB1)‑salt‑inducible kinase 1 (SIK1) signaling pathways was additionally investigated in ovarian carcinoma. The results of the present study demonstrated that ovarian carcinoma cells isolated from patients exhibited apoptosis resistance. Inhibition of TGF‑β expression led to an inhibition of growth, migration and invasion, in addition to a promotion of apoptosis, in ovarian carcinoma cells treated with paclitaxel. Studies have indicated that the LKB1‑SIK1 signaling pathway may be suppressed in ovarian carcinoma cells compared with normal ovarian cells, leading to activation of the EMT signaling pathway. The results of the present study demonstrated that upregulation of LKB1 promoted SIK1 expression and markedly suppressed the growth and aggressiveness of ovarian cancer cells. Upregulation of LKB1 additionally promoted apoptosis in ovarian carcinoma cells. In addition, the results of the present study demonstrated that the knockdown of LKB1 further promoted the expression of transforming growth factor‑β and EMT, which downregulated the chemosensitivity of ovarian carcinoma cells. Additionally, overexpression of LKB1 in ovarian carcinoma cells increased chemosensitivity, resulting in a significant inhibition of migration and invasion. The present findings indicated that the enhancement of LKB1‑SIK1 suppressed the growth and aggressiveness of ovarian carcinoma cells isolated from clinical patients, which subsequently contributed to an inhibition of metastatic potential. In conclusion, targeting the LKB1‑SIK1 signaling pathway to inhibit EMT may provide potential therapeutic benefits in ovarian carcinoma.

Papillary thyroid carcinoma with desmoid-type fibromatosis: A clinical, pathological, and immunohistochemical study of 14 cases

Papillary thyroid carcinoma (PTC) with desmoid-type fibromatosis (DTF) is characterized by genetic alterations of the fibroblasts. PTC-DTF is extremely rare, and the reports on such cases have been sporadic. Immunohistochemical staining using the antibody for beta-catenin is useful in diagnosing the variant. This report aims to describe the clinical, pathological, and immunohistochemical findings in 14 cases of PTC-DTF and to clarify the diagnostic significance of the variant. The patients included 9 women and 5 men, with a mean age of 49.3 years. PTCs with focal DTF components and with extensive DTF components included 7 cases each. No significant differences were noted in terms of age, gender, and serum thyroglobulin levels between extensive and focal DTF cases. On aspiration cytology, 12 cases were reported as suspicious for malignancy or malignant, and schwannoma or fibroma was suggested in 1 case each. The DTF components were histologically classified into 4 types, namely, central (4 cases), peripheral (1 case), mixed (7 cases), and diffuse type (2 cases). The stromal components were consistent with those of DTF. Immunohistochemically, fibroblasts in the DTF components showed nuclear and cytoplasmic expression for beta-catenin in 12 cases. The features are observed even in cases in which stromal components focally exist. Neither carcinoma cells nor the fibroblasts with Ki-67 labeling index >5% were found in all cases. We agree that PTC with nodular fasciitis-like stroma should be renamed to PTC-DTF.

Fibromatosis of the Breast: Diagnostic Accuracy of Core Needle Biopsy

OBJECTIVES

Fibromatosis of the breast is an uncommon neoplasm with potential for local recurrence. Treatment has traditionally been surgical excision with current trends toward conservative management. Given the option of observation after diagnosis by core needle biopsy (CNB), we sought to evaluate the accuracy of CNB for diagnosing fibromatosis.

METHODS

We identified a total of 31 cases in which fibromatosis had been diagnosed or included in the differential diagnosis on a CNB, an excision, or both. Morphology and immunohistochemical results were reviewed.

RESULTS

Aberrant nuclear immunoreactivity for β-catenin and absent staining for CD34 were the most useful studies to diagnose fibromatosis, and one or both were performed in 21 (68%) cases. High molecular weight cytokeratins and p63 were helpful to exclude spindle cell carcinoma. Of 26 cases confirmed as fibromatosis on excision, 22 (85%) were diagnosed as fibromatosis or fibromatosis was favored in the differential diagnosis on CNB. More frequent use of immunohistochemistry would likely have resulted in a greater number of definitive diagnoses. Fibromatosis was rarely mistaken for other nonmalignant stromal lesions, with no cases misdiagnosed as carcinoma.

CONCLUSIONS

CNB can be an accurate method of diagnosing fibromatosis, allowing observation for a select group of patients.

Inhibin A and inhibin B producing ovarian fibrothecoma revealed by suppression of follicle stimulating hormone (FSH) in a post-menopausal woman: report of the first case

In this report, we describe the first case ever reported in the literature, of an inhibin-A (INHA) and inhibin-B (INHB) producing fibrothecoma. A post-menopausal woman was referred to our unit because of follicle stimulating hormone (FSH) level below the reference interval for postmenopausal women. By contrast luteinizing hormone, hCG, and estradiol levels were within normal range. This discrepancy suggested the secretion of FSH inhibitory factors. INHB and INHA levels were markedly elevated for age, 475 pg/mL and 100 pg/mL, respectively. Ultrasonography and MRI showed a pelvic mass of indeterminate nature. Abnormal inhibin secretion is generally observed in granulosa cell tumors. In this case this etiology was unlikely because of low estradiol and AMH levels. Surgical exploration revealed a 10 cm mass of the left ovary proven histologically to be an ovarian fibrothecoma (OFT). After tumor removal, INHB and INHA levels decreased rapidly. Only three cases of OFT with an important secretion of INHB have been reported to date. INHA secretion has never been associated with OFT. There is a need to develop coupled hormone and imaging strategies to diagnose the source of INH secretion in case of FSH/LH discrepancy.

Ossifying Fibromyxoid Tumor May Express CD56 and CD99: A Case Report

Ossifying fibromyxoid tumor (OFMT) is an uncommon soft tissue neoplasm characterized by a combination of myxoid and/or fibrous stroma with areas of ossification. Although most authors postulate a neuroectodermal origin for this peculiar tumor, there is no agreement in the literature regarding its histogenesis. In this article, we present the immunohistochemical findings of a case of a 39-year-old white male with an OFMT of the soft tissue in the mandibular region. The tumor was positive to S-100 protein, glial fibrillary acidic protein, CD99, CD56 and negative to smooth muscle actin, cytokeratins AE1/AE3, epithelial membrane antigen, and CD68. To the best of our knowledge, this is the first case reported to be positive to CD56 and CD99. Immunoreactivity to these two antibodies, together with reactivity for S-100 protein and glial fibrillary acidic protein, suggests that OFMT is of a neuroectodermal origin. In our opinion, in the absence of reactivity to at least one neuroectodermal marker one should seriously question a diagnosis of OFMT.

Histochemical analysis of collagen fibers in giant cell fibroma and inflammatory fibrous hyperplasia

OBJECTIVE

The aim was to investigate collagen fibers in giant cell fibroma, inflammatory fibrous hyperplasia, and oral normal mucosa.

MATERIALS AND METHODS

Sixty-six cases were stained with picrosirius red. The slides were observed under polarization, followed by the measurement of the area and the percentage of the type I and type III collagens. The age and gender were obtained from the clinical records.

RESULTS

No differences could be observed in both the area and percentage of the type I and type III collagens within the categories of lesions and normal mucosa. In the giant cells fibroma, a greater area and percentage of type I collagen could be identified in individuals of less than 41.5 years (p<0.05).

CONCLUSION

The distribution of type I and type III collagen fibers in the studied lesions followed a similar pattern to that observed in the normal mucosa, indicating a normal collagen maturation process of type III to I. The study supports that multinucleated and stellate cells of the giant cell fibroma appear to be functional within collagen types III and I turnover. The greater amount of type I collagen identified in giant cell fibroma in individuals of less than 41.5 years reinforce the neoplastic nature of lesion.

Atypical Fibroxanthoma - Histological Diagnosis, Immunohistochemical Markers and Concepts of Therapy

BACKGROUND

Atypical fibroxanthoma (AFX) is an uncommon, rapidly growing cutaneous neoplasm of uncertain histogenesis. Thus far, there are no guidelines for diagnosis and therapy of this tumor.

PATIENTS AND METHODS

We included 18 patients with 21 AFX, and 2,912 patients with a total of 2,939 AFX cited in the literature between 1962 and 2014.

RESULTS

In our cohort, excision with safety margin was performed in 100% of primary tumors. Local recurrences were observed in 25% of primary tumors and parotid metastases in 5%. Ten-year disease-specific survival was 100%. The literature research yielded 280 relevant publications. Over 90% of the reported cases were negative for cytokeratins, S100, desmin and human melanoma black 45 (HMB-45). Recurrent AFX was reported in 7.6% and metastasizing AFX in 2.75% cases. No significant differences in the recurrence and survival rates following wide local excision versus Mohs microsurgery were observed. Twenty-year disease-specific survival rate was 97.8%.

CONCLUSION

A well-selected panel of immunohistochemical markers is necessary to establish AFX diagnosis with sufficient certainty. Adequately treated, AFX has an excellent prognosis, but long-term follow-up is recommended due to the potential for aggressive behavior.

Superficial acral fibromyxoma and other slow-growing tumors in acral areas

Superficial acral fibromyxoma (SAFM) is a rare fibromyxoid mesenchymal tumor with a predilection for the distal extremities and frequent nail bed involvement. Superficial acral fibromyxoma typically arises as a solitary, slow-growing nodule on a toe or finger, with the great toe being the most commonly affected site. Histopathologically, SAFM characteristically presents as a well-circumscribed but unencapsulated dermal tumor composed of spindle and stellate cells in a loose storiform or fascicular arrangement embedded in a myxoid, myxocollagenous, or collagenous stroma. The tumor often occupies the entire dermis and may extend into the subcutis and occasionally the underlying fascia and bone. The characteristic immunohistochemical profile of SAFM includes expression of CD34, epithelial membrane antigen (EMA), and CD99; it is notably negative for S-100 protein. We report 3 cases of SAFM and also provide a review of the literature on the clinical and histopathologic presentations of this unique entity as well as the differential diagnosis.

Atypical ossifying fibromyxoid tumor unusually located in the mediastinum: report of a case showing mosaic loss of INI-1 expression

Ossifying fibromyxoid tumor (OFMT) is a rare soft tissue tumor. OFMT mostly arises in subcutaneous tissue or skeletal muscle of the extremities and is extremely unusual in the mediastinum. OFMT is classified as typical, atypical, or malignant as tumor aggressiveness increases. Herein, we presented a case of atypical OFMT that developed in the mediastinum of a 43-year-old woman. Because of its predominant hypercellular area and some tumor cells with high nuclear grade, it was not a typical OFMT. However, it did not have a sufficient number of mitotic figures to be classified as malignant. Hence, we classified it as atypical OFMT with some apparent characteristic features of OFMT, such as the presence of spicules of bone at the periphery of the tumor. Upon immunohistochemistry, it was positive for vimentin, S-100 protein, and CD10, which was consistent with a diagnosis of OFMT. Particularly noteworthy was the mosaic loss of INI-1 expression. Some OFMT and other exceptionally rare tumors have been reported to exhibit mosaic INI-1 loss. Inactivation of INI-1 gene and deregulation of PHF1 gene are thought to be involved in tumorigenesis of OFMT. Therefore, we speculated that the mosaic loss of INI-1 observed in the present case might also be related to a kind of abnormality of INI-1 as was reported previously.

Estrogen and androgen receptors in inflammatory fibroid polyp (Vanek's tumor): case report

BACKGROUND/AIM

Vanek's tumor is an inflammatory fibroid polyp (IFP) of very low incidence, which originates in the submucosa of the stomach, duodenum, jejunum and ileum. The etiology of this tumor is still unknown. Histologically, IFP is characterized by submucosal spindle cell proliferation in fibromyxoid stroma with inflammatory infiltrate. The aim of the present study was to investigate the presence of estrogen and androgen receptors in IFP and compare it with its proliferative loci.

PATIENTS AND METHODS

The study analyzed a 79-year-old patient suffering from IFP. Analyses were performed by immunohistochemistry.

RESULTS

Androgen-positive spindle cells were detected at the periphery of onion skin-like formations. Estrogen receptor-positive cells were not detected and Ki67 showed low proliferative activity.

CONCLUSION

This case report shows for the first time the presence of androgen receptor-positive cells whose location corresponds with the distribution of Ki67-positive cells in IFP.

Cytoplasmic expression of Wilms tumor transcription factor-1 (WT1): a useful immunomarker for young-type fibromatoses and infantile fibrosarcoma

There is increasing evidence that Wilms' tumor transcription factor-1 (WT1) is expressed in the cytoplasm of neoplastic cells from different benign and malignant tumors. Only a few studies on WT1 cytoplasmic immunolocalization are available in pediatric tumors. The aim of the present study was to investigate immunohistochemically the expression and distribution of WT1 in a large series of soft tissue fibroblastic/myofibroblastic lesions occurring in children and adolescents. Notably WT1 was not expressed in nodular fasciitis and desmoid-type (adult) fibromatosis, while it stained diffusely and strongly in several infantile-type fibromatoses, such as fibrous hamartoma of infancy, myofibroma/myofibromatosis, and lipofibromatosis. Interestingly, WT1 cytoplasmic expression was also found in all cases (10/10) of infantile fibrosarcomas examined. The present study shows that a diffuse WT1 cytoplasmic expression is of complementary diagnostic value to conventional myofibroblastic markers (α-smooth muscle actin; desmin) in confirming diagnosis of young-type fibromatoses or infantile fibrosarcoma and in ruling out both desmoid-type fibromatoses and nodular fasciitis. WT1 cytoplasmic expression in infantile fibrosarcoma is a novel finding which could be exploitable as an immunomarker for this tumor. Although highly sensitive, WT1 cytoplasmic immunostaining is not specific for infantile fibrosarcoma, and thus it should be evaluated in the context of a wide immunohistochemical panel when pathologists are dealing with spindle cell lesions of soft tissues in children and adolescents. Accordingly we recommend that a correct diagnosis of fibroblastic/myofibroblastic soft tissue lesion in pediatric patients is usually achieved on the basis of a careful correlation of morphological and immunohistochemical findings in the appropriate clinical context. The different cellular localization of WT1, namely nuclear, cytoplasmic or nucleo-cytoplasmic, in different benign and malignant tumors supports the hypothesis that this transcription factor plays a complex role in tumorigenesis, likely as a chameleon protein functioning as either a tumor suppressor gene or an oncogene, depending on cellular context.

Identification of brown adipose tissue using MR imaging in a human adult with histological and immunohistochemical confirmation

OBJECTIVE

Manipulation of human brown adipose tissue (BAT) represents a novel therapeutic option for diabesity. The aim of our study was to develop and test a novel magnetic resonance (MR) imaging-based method to identify human BAT, delineate it from white adipose tissue, and validate it through immunohistochemistry.

DESIGN

A 25-year old Caucasian female with hyperparathyroidism-jaw tumor syndrome underwent parathyroidectomy. An (18)fluoro-2-deoxyglucose positron emission tomography (PET)-computed tomography (CT) scan performed after surgery ruled out malignancy but showed avid uptake within the mediastinum, neck, supraclavicular fossae, and axillae, consistent with BAT. Immunohistochemical staining using uncoupling protein-1 antibody was performed on one fat sample obtained from the suprasternal area during parathyroidectomy. Subsequently, serial MR scans were performed. Retrospectively, regions of interest (ROIs) were identified on MR corresponding to areas of high uptake on PET-CT. Prospectively, ROIs were identified on MR based on signal intensity and appearance and compared with PET-CT.

RESULTS

Of 111 retrospectively identified ROIs from PET-CT, 93 (83.8%) showed corresponding low MR signal: 25 of 25 mediastinum (100%), 29 of 31 neck (93.5%), 31 of 41 supraclavicular (75.6%), and 8 of 14 axillae (57%). Prospectively, 47 of 54 ROIs identified on MR (87%) showed a corresponding increased uptake on PET-CT. Serendipitously, the sample obtained at surgery corresponded with high uptake and low signal on subsequent PET and MR, respectively, and immunohistochemistry confirmed BAT.

CONCLUSION

We provide the first report for the reliable use of MR to identify BAT in a living human adult, with histological/immunohistochemical confirmation. Our data demonstrate proof of concept to support the development of MR as a safe, reproducible imaging modality for human BAT.

[Mitotically active cellular fibroma of ovary: a clinicopathologic analysis]

OBJECTIVE

To study the clinicopathologic characteristics of mitotically active cellular fibroma (MACF) of the ovary.

METHODS

The clinicopathologic features of 11 cases of MACF from 2008 to 2012 years were retrospectively reviewed and immunohistochemic EnVision method was performed.

RESULTS

The age of patients ranged from 21 to 65 years (mean = 46 years). The maximum tumor diameter varied from 6 to 16 cm (mean = 9.8 cm). The tumors were densely cellular and composed of intersecting bundles of spindle cells, sometimes associated with storiform pattern. The mitotic count ranged from 4 to 20 per 10 high-power field (mean = 8.4). Atypical mitotic figures were not identified and coagulative tumor necrosis was not found. There was at most mild to moderate degree of nuclear atypia. Immunohistochemically, 8 cases showed positive stain for vimentin and 5 cases expressed diffusely or focally WT-1. In 6 cases, Ki-67 positive index ranged from 5%-30%, including 1 case (10%), and 1 case (30%) in which mitotic figures were 20/10 HPF. CK,AE1/AE3, CD117, CD34, CD99 and desmin were negative in the detected 5 cases. Reticular fiber staining in 2 cases showed dense reticular fibers enveloping individual tumor cells. Ten patients who followed-up range from 4 to 38 months were alive without evidence of recurrence or disease progression. One patient was alive with local recurrence 94 months after surgery.

CONCLUSIONS

Cellular fibromatous neoplasm with mitotic count of ≥ 4/10 HPF but relatively bland nuclear features should be considered as MACF rather than ovarian fibrosarcoma. MACF is a group of ovarian tumor which carries a low malignant potential and occasional chance of recurrence.

Myxofibrosarcoma: cytomorphologic findings and differential diagnosis on fine needle aspiration

OBJECTIVE

To analyze the cytomorphologic findings of myxofibrosarcoma (MFS) on fine needle aspiration (FNA) and examine the differential diagnoses.

STUDY DESIGN

A retrospective review was undertaken of material from 22 patients with an FNA procedure of their tumor prior to resection. A tally was performed of all the features known in the literature, including myxoid matrix, spindle cells, nuclear pleomorphism, curvilinear vessels, and multinucleated cells. A review of the literature was also performed to elucidate any advances in the use of morphology and other modalities to deconvolute the challenging differential diagnosis. Clinicoradiologic characteristics and immunostaining were also analyzed and correlated.

RESULTS

FNA diagnoses included high-grade sarcoma (32%), recurrent MFS (23%), spindle cell neoplasm (18%), indeterminate-grade sarcoma (14%), low-grade sarcoma (9%), and pleomorphic adenoma (4%). Of the cases available for morphologic review, myxoid matrix was the most frequent observation (88%), followed by spindle cells (82%), nuclear pleomorphism (76%), multinucleated cells (71%), and curvilinear vessels (65%). Myxoid matrix, spindle cells, and nuclear pleomorphism were very often concomitant observations.

CONCLUSION

MFS demonstrates characteristic albeit nonspecific morphological findings and can overlap morphologically with other clinically significant entities based on FNA material.