Benign Mesenchymal Lesion Research Articles

Wilms' Tumor 1 (WT1): A Novel Immunomarker of Dermatofibrosarcoma Protuberans-An Immunohistochemical Study on a Series of 114 Cases of Bland-Looking Mesenchymal Spindle Cell Lesions of the Dermis/Subcutaneous Tissues.

Simple SummaryDermatofibrosarcoma protuberans (DFSP) is a superficial fibroblastic spindle cell sarcoma with a high rate of local recurrence (20% to 50%) but with a low metastatic potential. DFSP is characterized by COL1A1-PDGFB gene fusion and diffuse immunohistochemical expression of CD34. This immunomarker is especially useful in distinguishing DFSP from its morphological mimickers, especially when pathologists are faced with small biopsies. Apart from CD34, there are no additional diagnostic immunomarkers for DFSP, and thus, there is the need to identify more sensitive and specific markers for this sarcoma. Recently, Wilms’ tumor 1 (WT1) has been shown to be diffusely expressed in the cytoplasm of several benign and malignant mesenchymal spindle cell lesions. Based on this background, the aim of this study is to evaluate the immunohistochemical expression of WT1 protein in a series of bland-looking spindle cell lesions of the dermis/subcutis, emphasizing its potential diagnostic role in identifying DFSP among its morphological mimickers.Purpose: to investigate the immunohistochemical expression and distribution of Wilms’ tumor 1 (WT1) (transcription factor produced by the tumor suppressor gene of the same name) in a series of 114 cases of bland-looking mesenchymal spindle cell lesions of the dermis/subcutaneous tissues to establish whether this immunomarker is differentially expressed in dermatofibrosarcoma protuberans (DFSP) versus its potential morphological mimickers. Methods: This retrospective multi-centric immunohistochemical study included 57 DFSP cases, 15 dermatofibromas, 5 deep fibrous histiocytomas, 8 neurofibromas, 5 spindle cell lipomas, 8 dermal scars, 6 nodular fasciitis, 5 cutaneous leiomyomas and 5 solitary fibrous tumors. Among the 57 DFSP cases, 11 were recurrent lesions; 2 non-recurrent cases exhibited an additional “fibrosarcomatous” overgrowth and 1 recurrent and 2 primary tumors contained a minority of “giant cell fibroblastoma” components. Results: Most DFSP (95% of cases) exhibited cytoplasmic staining for WT1; 11/11 residual/recurrent tumors showed diffuse and strong WT1 cytoplasmic immunoreactivity; apart from neurofibromas, WT1 expression was lacking in all the other cases studied. Conclusions: The cytoplasmic expression of WT1 may be exploitable as a complementary diagnostic immunomarker to CD34 in confirming the diagnosis of DFSP and to better evaluate the residual/recurrent tumor component.

Pseudoangiomatous stromal hyperplasia: overview and clinical management

: Pseudoangiomatous stromal hyperplasia (PASH) is a benign mesenchymal lesion of the breast characterized by dense collagenous stroma forming “pseudoangiomatous” capillary-like spaces lined by slender spindle cells. A rare condition overall, PASH is most common in premenopausal women, though cases have been described at ages ranging from 14 to 86, and in men, usually associated with gynecomastia. While the exact etiology is unknown, PASH is considered hormonally responsive, with myofibroblastic proliferation leading to stromal hyperplasia. It may present as a palpable mass or an incidental imaging finding. The usual appearance on mammography and ultrasound is that of a well-circumscribed mass which must be differentiated from other benign and malignant lesions such as fibroadenoma, phyllodes tumor, and myofibroblastoma; histologically it must be distinguished from angiosarcoma. Core needle biopsy is indicated for diagnosis and must be concordant with imaging and clinical findings. PASH lesions should be surgically excised if enlarging, associated with symptoms, suspicious imaging findings are present, or other lesions are synchronously diagnosed that warrant removal; otherwise, observation with clinical and imaging follow-up can be considered. Progression and recurrence, each reported at rates of approximately 15–20%, indicate change in management and/or additional surgical intervention. PASH is not associated with an increased risk of breast cancer and prognosis is generally favorable.

ORAL SOLITARY FIBROUS TUMOR: MORPHOLOGIC AND IMMUNOHISTOCHEMICAL FINDINGS

Solitary fibrous tumor is an uncommon benign mesenchymal lesion. A 91-year-old male patient complained of an asymptomatic papule, reddish, pediculated, on the lateral border of the tongue, measuring 1.5 cm. An excisional biopsy was performed, and the diagnostic hypothesis of fibrous hyperplasia was considered. Microscopically, a circumscribed lesion was observed, with mesenchymal cells proliferation of variable morphology, with hypercellular and hypocellular areas. There was also ramifying vascular network, sometimes with a staghorn configuration, and the fibrous stroma exhibited focal areas of hyalinization. For the purposes of differential diagnosis, an immunohistochemical panel was performed. The positivity for vimentin, CD34, Bcl-2, and CD99, associated with lack of expression of S100, α–smooth muscle actin, CD68, and desmin led to the histopathologic diagnosis of solitary fibrous tumor. This case emphasizes the importance of immunohistochemical technique together with histopathologic features for the correct diagnosis of mesenchymal lesions.

MyoD1 expression in fibroepithelial stromal polyps

Fibroepithelial stromal polyps (FESPs) are benign polypoid mesenchymal lesions thought to arise from desmin-positive specialized stromal cells of the female genital tract. Although most cases are easily diagnosed by morphology alone, the morphology of FESPs is variable and in some instances can contain hypercellular stroma with numerous atypical desmin-positive cells, simulating botryoid embryonal rhabdomyosarcoma (ERMS). Recently, we encountered a cellular FESP showing desmin expression as well as nuclear immunoreactivity for the skeletal muscle-associated transcription factor MyoD1. Although these lesions are widely known to express desmin, there are very few studies examining expression of the more specific markers of skeletal muscle differentiation, myogenin and MyoD1. The aim of our study was to examine desmin, MyoD1, and myogenin expression in a series of 25 FESPs. Of the 25 cases, desmin expression was present in 23 (92%), at least focal MyoD1 expression was present in 10 (40%), and all cases were negative for myogenin. Follow-up data were available for all 25 cases, and none recurred or behaved in a malignant fashion. Awareness of this potential immunohistochemical pitfall and careful morphologic evaluation should allow for the confident distinction of MyoD1-positive FESP from botyroid ERMS in almost all instances.

DESMOID-TYPE FIBROMATOSIS OF THE BUCCAL MUCOSA: A CASE REPORT

Desmoid-type fibromatosis is a rare benign mesenchymal lesion that originates from musculoaponeurotic structures and rarely occurs in the head and neck region. The 32-year-old male patient was referred for evaluation of a submucosal lesion located in the left buccal mucosa, which was hardened, was painless, and had 3 months of evolution. Ultrasonography showed a well-defined, anechoic, and hypovascular mass. The histopathologic analysis showed proliferation of elongated, spindle-shaped cells of uniform appearance exhibiting condensed chromatin and eosinophilic cytoplasm with imprecise limits, sometimes with fasciculate pattern, associated with areas of prominent fibrosis with thick bundles of collagen. The proliferation produces dissociation and degeneration of muscle fibers. Immunohistochemical reaction revealed, in tumor cells, negativity for protein S100 and CD34 besides immunoexpression focal positive for α actin and β catenin. The cells strongly expressed vimentin. Morphologic and immunohistochemical findings were compatible with desmoid type fibromatosis. The patient is under clinical follow-up of 8 months without relapse. Desmoid-type fibromatosis is a rare benign mesenchymal lesion that originates from musculoaponeurotic structures and rarely occurs in the head and neck region. The 32-year-old male patient was referred for evaluation of a submucosal lesion located in the left buccal mucosa, which was hardened, was painless, and had 3 months of evolution. Ultrasonography showed a well-defined, anechoic, and hypovascular mass. The histopathologic analysis showed proliferation of elongated, spindle-shaped cells of uniform appearance exhibiting condensed chromatin and eosinophilic cytoplasm with imprecise limits, sometimes with fasciculate pattern, associated with areas of prominent fibrosis with thick bundles of collagen. The proliferation produces dissociation and degeneration of muscle fibers. Immunohistochemical reaction revealed, in tumor cells, negativity for protein S100 and CD34 besides immunoexpression focal positive for α actin and β catenin. The cells strongly expressed vimentin. Morphologic and immunohistochemical findings were compatible with desmoid type fibromatosis. The patient is under clinical follow-up of 8 months without relapse.

Optimal treatment of pseudoangiomatous stromal hyperplasia of the breast

Pseudoangiomatous stromal hyperplasia (PASH) is a benign mesenchymal proliferative lesion of the breast. Owing to the rarity of PASH, the pathogenesis, clinical manifestation, and optimal treatment of this condition remain unclear. We aimed to clarify the appropriate management of PASH. We performed a retrospective analysis of the clinicopathological data of 66 cases with a diagnosis of PASH, confirmed by core needle biopsy (CNB) or surgical excision at Severance Hospital between 2000 and 2016. The primary endpoint was pathologic results after surgical excision of the lesion that confirmed PASH by CNB. The secondary endpoint was progression after the first treatment. The median age of patients was 41 years (range, 14-61 years). Findings on medical imaging were nonspecific. CNB was performed in 61 cases, with a diagnosis of PASH confirmed in 39 cases (63.9%). No malignant or premalignant cells directly arising from PASH were identified after surgical excision that confirmed PASH via CNB. The progression rate after the first treatment was 16.6%, with lesion size, enlargement of palpable mass size, and a diagnosis other than PASH on CNB being factors associated with progression. CNB is sufficient to confirm PASH what is necessary for an abnormal imaging or suspicious physical examination finding. Surgical excision is not necessarily indicated to rule out occult malignancy after a diagnosis of PASH. Close monitoring or surgical excision are required to manage large lesions (>3cm) or progressive growth of a PASH lesion.

Clinicopathological features of peripheral ossifying fibroma in a series of 41 patients.

Peripheral ossifying fibromas are benign mesenchymal lesions that usually arise in the anterior maxilla of young female patients. Histologically they consist of spindle cell proliferation with focal mineralisation. We reviewed 48 specimens from 41 patients and recorded the clinical data, sex, and age of the patients, site and size of the lesions, treatment, and postoperative outcome. Histologically the presence of mature, woven bone, cementum, and calcifications were evaluated and evaluated immunohistochemically. Lesions were more frequent in female patients in the third and fourth decade, and were usually in the lower maxilla and smaller than 2cm. All lesions were conservatively excised, and they relapsed in eight patients. Histopathologically, the lesions were poorly circumscribed, moderately cellular proliferations, with no discernible architectural pattern. All tumours showed some degree of mineralisation, the presence of immature bone being the most common. Immunohistochemical examination showed staining of tumoural cells for smooth muscle actin and CD68. Lesions tended to occur more commonly in female patients, but one decade later than usually reported. We found a higher recurrence rate in lesions that contained cementum-like material but without bone formation, suggesting a lack of maturation in this group. Immunohistochemical results were consistent with myofibroblastic differentiation but they added no information about the behaviour of the lesions.

GRANULAR CELL TUMOR S-100 NEGATIVE VARIANT

Granular cell tumor is a benign mesenchymal lesion that occurs more often in the oral cavity and skin. Its cell origin is controversial, including muscle, fibroblasts, neural crest, neural sheath and histiocytes. Granular cell tumors composed of larger and polygonal cells with abundant eosinophilic granular cytoplasm. Classic granular cell tumor shows positive immunostaining for S-100 and vimentin, and in some cases, positive CD68 staining is also reported positive. However, three cases of S100 negative granular cell tumor in oral mucosa and several cases in skin have also been reported in the literature recently. Therefore, the purpose of this study is to report a case of oral S100 negative granular cell tumor to increase the awareness of this entity. A 79-year-old female patient presented with a small asymptomatic, circumscribed mass lesion in the posterior lateral aspect of the palatal torus. Histologically, the specimen was covered by keratinized stratified squamous epithelium showing no pseudoepitheliomatous hyperplasia. The lamina propria consisted of fibrous connective tissue with chronic inflammation and cluster or sheet of large polygonal cells with granular cytoplasm. Immunohistochemistry showed that the granular cells stain positive for CD68 but negative for S100. Currently there is no difference in recommended treatment or in prognosis of S100 negative from S100 positive granular cell tumor. However, it is important to be aware of this rare variant of granular cell tumor for stablishing correct diagnosis.

Angiomyolipoma of the Oral Cavity: A Rare Case Report

Angiomyolipoma (AML) is a rare, benign tumor composed of thick-wall blood vessels, smooth muscle component and mature adispose tissue. Differentiation from other benign and malignant mesenchymal lesions of oral cavity depends on recognition of these three histologic components, and immunohistochemical (IHC) techniques are also helpful. This tumor arise from perivascular epithelioid cells (PEComas) and kidneys followed by liver are the main locations of this soft tissue tumor. AMLs are rarely found in oral cavity and few case reports of oral AML have been reported in the literature. We report the first case of concurrent occurrence of AML of the tongue and peripheral giant cell granuloma of the gingiva in a 59-year-old patient. Clinically it was presented as a painless nodular mass with a smooth surface on the dorsal of the tongue. Based on histopathologic features and IHC staining the diagnosis of oral AML was done. The other lesion was a small sessile mass in interdental papillae of the lower incisors and microscopic examination showed the histologic features of a peripheral giant cell granuloma. Concurrent occurrence of PGCG which is a reactive mucosal hyperplasia and AML in our patient, could show the probable role of local trauma in the pathogenesis of these lesions.

A Rare Case of Intravesical Angiomyofibroblastoma

To study the first reported case of intravesical angiomyofibroblastoma (AMFB). AMFB is an uncommon benign mesenchymal lesion, mostly described in the lower female genital tract, especially in the vulva and less commonly in the vagina. It is rarely seen in the male genital tract. The importance of this rare neoplasm is related to its potential mimicry of more infiltrative and prognostically less favorable lesions, such as aggressive angiomyxomas, that are found in the same anatomic area. A 26-year-old man presented to us with hematuria. Investigations revealed an intraluminal polypoidal lesion of approximately 92 × 77 × 76 mm within the urinary bladder. Cystoscopy revealed a large well-circumscribed tumor with a pedicle, attached to the inferolateral wall of the bladder near the bladder neck. Open exploration and en bloc excision of the bladder mass was done. Histopathology and immunohistochemistry (IHC) confirmed the diagnosis of AMFB. AMFB presents as a well-circumscribed superficial mass. Complete excision of the tumor for histopathologic and IHC examination is essential for diagnosis. This rare tumor shows morphologic similarity to some more aggressive tumors with less favorable outcome; hence, it needs to be differentiated from those. IHC is helpful but not always conclusive in the diagnosis of this rare neoplasm. This being the first-ever reported case of intravesical AMFB bears a significant importance. Careful clinical assessment, operative management, and histopathologic examination are of utmost importance in making a precise diagnosis and management of the patient.

Clinicopathologic study of calcifying fibrous tumor of the gastrointestinal tract: a case series

Calcifying fibrous tumor (CFT) is a rare benign mesenchymal lesion known to arise at multiple body sites that may clinically mimic other more aggressive lesions in the gastrointestinal (GI) tract. In this study we describe the clinicopathologic findings of 28 GI tract CFTs. Tumors predominantly arose in middle-aged adults with a slight female predominance. The most commonly involved sites were small bowel and colon, followed by stomach and appendix. Tumors ranged from 0.3 to 9.3 cm (median 1.4 cm), and submucosa was the most commonly involved layer. All tumors were well circumscribed and unencapsulated. Microscopically, tumors were hypocellular and composed of spindle cells with abundant, haphazardly arranged hyalinized collagen. No necrosis and less than one mitosis per 10 HPF were identified in all cases. Calcification was present in most (81%) of the cases. All cases had lymphoplasmacytic inflammatory infiltrates either scattered throughout the lesion with occasional perivascular conglomeration or in the form of lymphoid aggregates. A lymphoplasmacytic cuff was usually present (81%). Immunostains showed variable CD34 immunoreactivity and variable numbers of IgG4-positive plasma cells. The lesional cells were negative for DOG-1, ALK-1, S100, C-kit, Sox10, Melan A, HMB45, desmin, CK7, and CK20, and showed cytoplasmic staining for β-catenin. Follow-up information was available in 5 cases with no recurrences reported to date (mean follow-up, 3 years). CFT is a rare benign tumor that can occur in part of the GI tract and should be distinguished from other mesenchymal tumors due to its low risk of recurrence.

Protein gene product 9.5 (PGP9.5) expression in benign cutaneous mesenchymal, histiocytic, and melanocytic lesions: comparison with cellular neurothekeoma

Cellular neurothekeoma (CNTK) frequently enters the differential diagnosis of a benign dermal cellular proliferation. Diagnosis often relies on immunohistochemistry including the use of protein gene product 9.5 (PGP9.5). A previous study demonstrated PGP9.5 expression across a wide variety of soft tissue neoplasms. We explored the utility of this antibody in distinguishing CNTK from other benign dermal-based lesions. A cohort of CNTK (n=7) and benign cutaneous lesions of neural (n=28), fibrohistiocytic (n=23), fibroblastic (n=25), histiocytic (n=18), myofibroblastic (n=7), smooth muscle (n=14), and melanocytic (n=12) differentiations were immunostained with PGP9.5. Staining was graded by H-score and compared with CNTK. A significantly higher H-score was found in CNTK compared with the fibrohistiocytic (p=0.0001), histiocytic (p=0.0016), myofibroblastic (p=0.0003), smooth muscle (p<0.0001), and melanocytic (p=0.0004) groups, with the exceptions of plexiform fibrohistiocytic tumour, xanthoma, and xanthogranuloma. No significant difference was found when comparing CNTK with fibroblastic and neural lesions, with the exceptions of neurofibroma and perineurioma. In conclusion, PGP9.5 is helpful in distinguishing CNTK from most benign cutaneous fibrohistiocytic, histiocytic, myofibroblastic, smooth muscle, and melanocytic lesions. In addition to CNTK and neural lesions, PGP9.5 is also expressed in benign fibroblastic lesions, and therefore distinction of these lesions should not be based on PGP9.5 positivity.

Superficial acral fibromyxoma: clinicopathological, immunohistochemical, and molecular study of 11 cases highlighting frequent Rb1 loss/deletions

Superficial acral fibromyxoma (SAF) is an uncommon benign dermal mesenchymal lesion of adults with predilection for acral sites, in particular the nail region. To date, less than 300 cases have been reported. SAFs consistently express CD34, but other diagnostic markers or specific genetic alterations have not been established yet. We describe 11 SAFs occurring in 7 men and 4 women aged 37 to 86years (median, 48 years). Mean size was 6mm (range, 4-20mm). Affected sites were fingers (n=5), toes (n=3), heel (n=1), calf (n=1), and unspecified digit (n=1). None of 10 patients with available follow-up (2-60months; median, 24months) developed recurrence. Histology showed relatively hypocellular vaguely lobulated nodules composed of bland-looking spindled or stellate fibroblast-like cells arranged into storiform or loose fascicles within a variably myxoid, fibromyxoid, or collagenous vascularized stroma. Immunohistochemistry showed expression of CD34 (9/10) and focal weak reactivity for epithelial membrane antigen (2/11). None of the lesions expressed protein S100 (0/11), MUC4 (0/11), or STAT6 (0/11). Loss of Rb1 immunoexpression was observed in 9 (90%) of 10 cases. All 7 cases with successful RB1 fluorescence in situ hybridization testing showed RB1 gene deletions, which was variably associated with co-loss of the corresponding 13q12 signal (monosomy at the 13q region). To our knowledge, this is the first study investigating the expression status of the tumor suppressor Rb1 in SAF by immunohistochemistry and fluorescence in situ hybridization. Our results showed frequent Rb1 deficiency as a possible driver molecular event in SAF (seen in 90% of cases) indicating relationship of SAF to the RB1-deleted tumor family.

Pseudoangiomatous Stromal Hyperplasia Presenting as Rapidly Growing Bilateral Breast Enlargement Refractory to Surgical Excision.

Pseudoangiomatous stromal hyperplasia (PASH) is a benign proliferative mesenchymal lesion of the breast. PASH presents as a palpable or mammographically detectable mass or is an incidental microscopic finding in up to 23% of breast biopsies. Its pathogenesis is unclear but may involve hormonal factors, as recently postulated. Its clinical, cytological, and radiological characteristics resemble those of other benign tumors, including low-grade angiosarcomas and phyllodes tumors. Because of its uncertain pathogenesis, PASH is usually treated via surgical excision, with post-excision recurrence rates ranging from 7% to 22% [1]. Although several cases of PASH have been recently reported, cases of PASH involving large, rapidly growing lesions refractory to surgical incision are rare [2]. In this study, we report our experience with a case of PASH that presented as rapidly growing bilateral breast enlargement refractory to surgical excision. We also review the pertinent literature, including the clinical and histopathological features, pathogenesis, imaging findings, treatment, and prognosis of PASH.

Update on Select Benign Mesenchymal and Meningothelial Sinonasal Tract Lesions.

Several benign and malignant mesenchymal and meningothelial lesions may preferentially affect or extend into the sinonasal tract. Glomangiopericytoma (GPC, formerly sinonasal-type hemangiopericytoma) is a specific tumor with a predilection to the sinonasal tract. Sinonasal tract polyps with stromal atypia (antrochoanal polyp) demonstrate unique histologic findings in the sinonasal tract. Juvenile nasopharyngeal angiofibroma (JNA) arises from specialized tissue in this location. Meningioma may develop as direct extension from its intracranial counterpart or as an ectopic tumor. Selected benign mesenchymal tumors may arise in the sinonasal tract and pose a unique differential diagnostic consideration, such as solitary fibrous tumor and GPC or lobular capillary hemangioma and JNA. Although benign and malignant vascular, fibrous, fatty, skeletal muscle, and nerve sheath tumors may occur in this location, this paper focuses on a highly select group of rare benign sinonasal tract tumors with their clinicopathological and molecular findings, and differential diagnosis.

Giant acrochordon of vulva: A rare occurrence

Acrochordon , commonly called skin tag or fibroepithelial polyp is a benign mesenchymal lesion which is usually hyperpigmented and appears as surface nodule or papilloma on healthy skin. Most acrochordons vary in size from 2-5 mm in diameter, although larger acrochordons up to 5 cm in diameter are sometimes evident. The most frequent localizations are the neck and the axilla, but any skin fold including groin may be affected. Genital presentation in females has a greater predilection for the vulvovaginal region as compared to cervix. Diagnosis is mainly based on histopathology which is necessary not only to rule out malignancy but also to differentiate from other lesions like angiomyxoma which mimics fibroepithelial polyps. The case report is rarest of its kind with regard to its size as the polyp measured 20x16x12 cm and weighed approximately 3 kilograms. Thus, it becomes one of the largest acrochordons reported ever.NJDVL Vol. 13, No. 1, 2015 Page: 70-72

Treatment of Pseudoangiomatous Stromal Hyperplasia of the Breast: Implant-Based Reconstruction with a Vascularized Dermal Sling.

Pseudoangiomatous stromal hyperplasia (PASH) of the breast is a benign mesenchymal lesion with incidental histologic findings. Surgical excision is recommended as the treatment of choice for PASH, although the recurrence rates after excision range from 15% to 22%. A 46-year-old-female presented with a six-month history of bilateral breast enlargement and painful sensation mimicking inflammatory carcinoma. Imaging studies demonstrated innumerable enhancing nodules in both breasts. Due to the growth of the lesions and progressive clinical symptoms, bilateral subcutaneous mastectomy was performed. Grossly, the specimens were round and well-circumscribed, and the histologic examination revealed PASH. After mastectomy, we created a pocket with the pectoralis major muscle and a lower skin flap, which was deepithelized. Anatomical mammary implants were inserted, and the nipple areolar complex was transferred to a new position as a free graft. The aesthetic result was satisfactory after twelve months of follow-up.

Prepubertal-type vulva fibroma: a clinicopathological study of two cases

To study the clinicopathological features, immnophenotype and differential diagnosis of prepubertal-type vulva fibroma (PVF). Clinical, radiological and pathological features of 2 cases of PVF were analyzed along with a literature review. Both patients were females of 8.5 and 54 years of age, presented with recurrent unilateral mass at the labium major respectively. Grossly, cut surface of the tumor appeared as the gray fibrous tissue without any definited lump detected. Histologically, the ill-circumscribed lesion located predominantly in the deep dermis with an extension into the subcutaneous tissue. They had a low cell density consisting of scattered spindle shaped fibroblast-like cells and a large amount of collagen fiber matrix, nuclear atypia not seen and mitotic figures scanty. The tumor cells extended downward under the epithelium and infiltrated between the fat tissue, nerve fibers as well as the capillaries making a lesion looked somewhat like a harmatoma. Immunohistochemically, the spindle cells were uniformly positive for vimentin, weakly positive for CD34, and negative for alpha-smooth muscle actin (SMA), muscle specific actin (HHF35), desmin, h-caldesmon, CD99, S-100 protein, bcl-2, beta-catenin, estrogen and progesterone receptors. PVF is a benign mesenchymal lesion with a predilection of involving the vulva of prepubertal girls or adults in rare cases. PVF may represent an overgrowth of normal stromal tissue of vulva. Approximately one third of the tumors develop local recurrence due to incomplete excision, however, there is also occasionally spontaneous regression.

NY-ESO-1 (CTAG1B) expression in mesenchymal tumors

New York esophageal squamous cell carcinoma 1 (NY-ESO-1, CTAG1B) is a cancer-testis antigen and currently a focus of several targeted immunotherapeutic strategies. We performed a large-scale immunohistochemical expression study of NY-ESO-1 using tissue microarrays of mesenchymal tumors from three institutions in an international collaboration. A total of 1132 intermediate and malignant and 175 benign mesenchymal lesions were enrolled in this study. Immunohistochemical staining was performed on tissue microarrays using a monoclonal antibody for NY-ESO-1. Among mesenchymal tumors, myxoid liposarcomas showed the highest positivity for NY-ESO-1 (88%), followed by synovial sarcomas (49%), myxofibrosarcomas (35%), and conventional chondrosarcomas (28%). Positivity of NY-ESO-1 in the remaining mesenchymal tumors was consistently low, and no immunoreactivity was observed in benign mesenchymal lesions. On the basis of these findings, nearly 90% of myxoid liposarcomas, as well as a significant proportion of synovial sarcomas, myxofibrosarcomas, and conventional chondrosarcomas are good candidates for immunotherapy targeting NY-ESO-1.

Giant Fibroepithelial Polyp of Vulva – A Rarest of its Occurrence

Fibro epithelial stromal polyps which are benign mesenchymal lesions that typically occur in skin, oral cavity, urinary tract and genital area pose diagnostic problems because of bizarre cytomorphology. Genital presentation has a greater predilection for the vulvovaginal region and rarely the cervix. Cases of fibro epithelial polyp in vulva have been rarely reported and usually they do not grow larger than 5 cm in diameter and are found incidentally during routine gynecologic exams. Diagnosis mainly based on histopathology has to be done to rule out malignancy and also to differentiate from other lesions like angiomyxoma which mimics fibro epithelial polyps. The case report presented is a rarest of its kind as regards to its size because the polyp in this patient measured 35x23x11 cm and weighing 10 kg which becomes the largest polyp reported ever.