Osteoclast-rich, proximal-type epithelioid sarcoma: clinicopathologic features of 3 unusual cases expanding the histomorphological spectrum.

Epithelioid sarcoma (ES) displays a wide clinicopathologic spectrum. On histopathology, osteoclast-like giant cells have been rarely described in these tumors. A 45-year-old gentleman presented with a perineal swelling of 6-month duration. Radiologic imaging disclosed a large, highly vascular tumor mass in his perineal region that was diagnosed elsewhere as pigmented villonodular synovitis. A 58-year-old lady presented with a recurrent tumor in her right inguinolabial region for which she underwent multiple tumor resections in the past. A 33-year-old lady presented with a right inguinal swelling of 1-month duration that was diagnosed elsewhere as a non-Hodgkin lymphoma on fine needle aspiration cytology. Histopathologic examination of tumors in all the 3 cases revealed epithelioid to "rhabdoid-like" cells arranged in a diffuse pattern interspersed with many osteoclast-like giant cells. The first tumor also revealed focal pseudoangiosarcomatous areas and heterotopic bone formation. By immunohistochemistry, tumor cells in all 3 cases were positive for AE1/AE3, epithelial membrane antigen, and CD34 and were completely negative for INI1/SMARCB1. CD68 immunostaining in 2 tumors highlighted osteoclast-like giant cells. Osteoclast-rich, proximal-type ES are unusual tumors, indicative of an expanding spectrum of ESs. Awareness of this histopathologic pattern and diagnostic confirmation with necessary immunohistochemical stains is crucial to avoid misinterpretation, as these tumors are clinically aggressive and are treated with wide local excision and optional adjuvant radiation therapy.

Clinicopathological spectrum of a series of Merkel cell carcinomas diagnosed at a tertiary cancer referral center in India, with current concepts.

Merkel cell carcinoma (MCC) is a rare, clinically aggressive primary cutaneous neuroendocrine carcinoma. The present series describes clinicopathological features of 16 MCCs diagnosed at a tertiary cancer referral center. Sixteen MCCs occurred in 10 men and 6 women (M/F = 1.6:1), between the ages 37 and 74 years (mean, 58.3; median, 58.6), commonly in lower extremities (7) (43.7%) and head and neck sites (5) (31.2%), followed by upper extremities (3) (18.7%) and abdominal wall (1). Tumor size varied from 0.5 to 9.9 cm. Histopathologically, most tumors were composed of round to oval cells, mostly arranged diffusely with hyperchromatic nuclei, including "sudden" pleomorphism in some tumors. Variable features included coexisting Bowen disease (2/16), along with squamous, pseudoglandular, and rhabdomyoblastic dedifferentiation, all in a single tumor. Immunohistochemically, tumor cells were positive for at least a single epithelial marker in all 16 cases (100%) cases, including CK20, mostly paranuclear "dot-like" (12/13, 92.3%); CK (8/9, 88.8%), AE1/AE3 (3/3, 100%), and CK7 (1/6, 16.6%), along with neuroendocrine markers (16/16, 100%), including synaptophysin (11/13, 84.6%), chromogranin (12/15, 80%), and CD56 (4/4, 100%). Among other immunohistochemical markers, positive CKIT/CD117 was positive in 3 of 3 tumors. Surgical resection was performed in 11 (100%) of 11 cases, with adjuvant chemotherapy offered in a single case. Two cases with large-sized tumors, along with another case developed lymph node metastasis, including 1 who later developed pulmonary metastasis. Two patients were free of disease and 2 were alive with disease. Merkel cell carcinomas exhibit a diverse histopathological spectrum, including coexisting Bowen disease and, rarely, rhabdomyoblastic dedifferentiation, in some cases. Optimal immunohistochemical markers include CK20, synaptophysin, chromogranin, and CD56 for a timely diagnosis. Surgical resection is the treatment mainstay. Large-sized tumors and MCCs showing dedifferentiation portend a relatively more aggressive clinical course. Other recent developments in this tumor are discussed herewith.

Pasteurization of bone for tumour eradication prior to reimplantation - an in vitro & pre-clinical efficacy study.

BACKGROUND & OBJECTIVES: In current era of limb-salvage therapy, pasteurization of bone sarcomas is receiving growing attention as a potential extracorporeal treatment and cost-effective alternative to allografts and radiation before surgical reimplantation. Detailed in vitro and in vivo pre-clinical study to evaluate efficacy of pasteurization to eradicate malignant cells has not been reported yet. The present study was carried out to assess the efficacy of pasteurization to kill tumour cells both in vitro and in vivo. METHODS: Surgically resected specimens of osteosarcomas (n=4) were cut into equal halves and one section was pasteurized by heating at 60°C to 65°C for 40 min. Paired samples before and after pasteurization were studied in vitro for DNA ploidy, evaluation of histological change and elimination of mitotic activity. These tissues were transplanted in immune-deficient NOD-SCID mice to evaluate effect on tumour-generating ability, presence of human nuclei, osteopontin and cytokine/chemokines released in tumour-transplanted mice. RESULTS: Non-pasteurized tumour samples had viable tumour cells which exhibited significant growth in culture, increased proliferative ability and clonogenic potential while respective pasteurized tumour tissues did not grow in culture and did not exhibit clonogenicity. Flow cytometry revealed that propidium iodide positive dead cells increased significantly (P< 0.01) post pasteurization. Seven of 12 non-pasteurized tumour transplanted mice demonstrated tumour-forming ability as against 0 of 12 in pasteurized tumour transplanted mice. Solid tumour xenografts exhibited strong expression of anti-human nuclei and osteopontin by immunohistochemistry as well as secretary human interluekin-6 (IL-6) while pasteurized mice failed to express these markers. INTERPRETATION & CONCLUSIONS: This study has provided a basis to establish pasteurization as being efficacious in ensuring tumour eradication from resected bone tumour specimens. Pasteurized tumour bearing bone can thus safely be used to reconstruct large defects after tumour resection.

Pulmonary adenofibroma: clinicopathological study of 3 cases of a rare benign lung lesion and review of the literature.

Pulmonary adenofibroma is a rare benign biphasic tumor of the lung composed of epithelial and stromal components. We report 3 cases of this unusual lesion of lung in a male (25 years old) and 2 female (40 and 55 years old) patients. Breathlessness on exertion and mild left-sided chest pain of 1 month's duration were the main concerns in 2 patients, whereas the third had cough and hemoptysis for 3 months. Chest radiograph and computed tomography scan revealed a well-circumscribed, subpleural homogenous mass in left lower chest fields in 2 cases and solid-cystic lesion in left upper lobe in the third patient. All 3 patients underwent lobectomy, following biopsy in 2 cases. Histology revealed a well-circumscribed lesion composed of complex glandlike spaces lined by cuboidal to columnar epithelium surrounded by a hyalinized spindle-cell fibroblastic proliferation reminiscent of adenofibroma of the female genital tract or fibroadenoma of the breast. Immunohistochemical examination supported the diagnosis of a benign pulmonary adenofibroma. All 3 patients were are alive and doing well with no evidence of recurrent or metastatic disease. Diagnosis on biopsy can be challenging and may be misinterpreted as well-differentiated adenocarcinoma with extensive fibrosis or low-grade sarcoma. Frozen-section consultation will be a valuable adjunct in planning for limited lung resection of this benign lung lesion. Although we described 3 cases of pulmonary adenofibroma, still this is the largest published series of this rare entity till date. The possible histogenesis and various differential diagnoses are discussed along with literature review.

Toward an evidence-based proposal for the best minimal immunohistochemical panel to infer lung carcinoma in metastatic supraclavicular lymph node.

Carcinomas from either pulmonary or extrapulmonary sites can metastatise to supraclavicular lymph nodes. Immunohistochemistry (IHC) is invaluable to comment on the possible primary site. However, the optimal number of antibodies to be tested is debatable. Seven antibodies were tested on 135 metastatic supraclavicular lymph node biopsies to propose a "best minimal" IHC panel to infer lung carcinoma, incorporating the principles of "evidence-based medicine." The 135 cases were divided into the following: category I (110 cases), wherein the primary was in the lung based on histologic analysis (Ia, n = 14 [12.7%]), cytologic analysis (Ib, n = 43 [39.1%]), or strong clinicoradiologic evidence (Ic, n = 53 [48.2%]), and category II (25 cases) with a histologically proven extrapulmonary primary site. Categories Ia and Ib were together designated as the "control group," and category Ic was designated as the "test group." The antibodies tested were cytokeratin (CK 7, CK20), epithelial membrane antigen, carcinoembryonic antigen, thyroid transcription factor-1 (TTF-1), surfactant protein B (SPB), and vimentin. Results of both individual and panels of antibodies were statistically evaluated. The sensitivity and specificity of single antibodies for inferring a lung primary was as follows: CK7 (90%/56%), CK20 (98%/40%), epithelial membrane antigen (90.9%/4%), carcinoembryonic antigen (80.9%/36%), TTF-1 (62.7%/100%), SPB (65.6%/100%), and vimentin (60.9%/60%). The highest sensitivity (85%) and specificity (100%) were seen with a 4-antibody panel: CK7, CK20, TTF-1, and SPB. This panel revealed the highest binomial probability (.8), for diagnosing lung cancer. The results were validated using a "split sample method," and a high concordance was noted between the control and test groups. To conclude, such evidence-based validated studies analyzing IHC results would be invaluable to guide the practice of surgical pathology in the future.

Chemotherapy compliance in patients with osteosarcoma.

PURPOSE: Histological response (HR) to neoadjuvant-chemotherapy (NACT) is considered as a robust prognostic marker in treated osteosarcomas. Chemotherapy compliance can affect both, dose intensity and density and may affect the final outcome in these cases. This vital aspect has been inadequately addressed and therefore merits further investigation. METHOD: A retrospective study of NACT-treated osteosarcoma patients, during the year 2010 was conducted. Compliance was defined as receipt of planned cycles of chemotherapy in the planned doses, within the planned duration or up to 25% additional time. HR was assessed by grading for histological necrosis (HN). Good responders (GR) included those with tumors showing ≥90% HN. RESULTS: Of 124 patients, 115 were analyzed for post-NACT HR. Of the 73 (64%) compliant patients, 47 were GR and of the 42 (36%) non-compliant patients, 18 were GR. There was significant association between GR and compliance (P = 0.031). However, at a median follow-up of 7.9 months, there was no significant difference in survival between the noncompliant versus compliant group. Non-compliance was justifiable in 26 patients and not justifiable in 16 patients. Using univariate analysis, T-size, pain, performance status, albumin, LDH, and education were identified as significant factors, while in multivariate analysis, only poor performance status was identified as an independent variable for non-compliance. CONCLUSIONS: Two-thirds patients were found to be compliant with NACT. There was a significant association between GR and compliant patients. Significant correlation between compliance and survival may be established with a longer follow-up particularly since "good necrosis" is generally predictive of good survival.

Metastatic paraganglioma presenting as a primary shoulder mass.

Paragangliomas uncommonly metastasize, including to the bones, wherein these tumors are designated as malignant paragangliomas. A 56-year-old man presented with pain and immobility in his right arm for 1 year. He had a history of controlled hypertension and diabetes mellitus for 2 years. He had also been taking anti-anxiety medications for 25 years. His shoulder imaging revealed an expansile, lytic, destructive lesion in the glenoid cavity, measuring 4.6 × 3.9 × 3.2 cm, involving the adjacent bones and soft tissues. A whole-body PET-CT scan revealed a hypermetabolic destructive mass in the right glenoid cavity and another lesion in his abdomen in the aortocaval region. Initial biopsy and subsequent scapular resection microscopically revealed a multinodular tumor with polygonal cells arranged in a nesting and diffuse pattern, in a vascularized and sclerotic stroma. Tumor cells displayed moderate to abundant, eosinophilic to clear cytoplasm, fine nuclear chromatin, focal intranuclear inclusions, and scattered mitotic figures. Immunohistochemically, tumor cells were positive for vimentin, synaptophysin, chromogranin, and CD56 and negative for AE1/AE3, CK, EMA, CD10, SMA, Melan A, HMB-45, desmin, and S100-P. Biopsy of the abdominal mass revealed foci of tumor cells resembling the scapular tumor. Diagnosis of a malignant paraganglioma was finally offered. The patient's post-operative blood pressure is controlled. Currently, his urinary vanillylmandelic acid and metanephrine levels are normal. He is asymptomatic 11 months post-surgery and is on follow-up. This unusual case is presented to increase a diagnostic index of suspicion for a malignant paraganglioma, including at unconventional musculoskeletal sites. The diagnostic challenge and therapeutic implications are discussed herewith.

Accuracy of concurrent visual and cytology screening in detecting cervical cancer precursors in rural India.

The high burden of cervical cancer and inadequate/suboptimal cytology screening in developing countries led to the evaluation of visual screening tests, like visual inspection with acetic acid (VIA) and Lugol's iodine (VILI). We describe the performance of VIA, VILI and cytology, carried out in a multinational project called "Screening Technologies to Advance Rapid Testing" in 5,519 women aged 30-49 years, in detecting cervical intraepithelial neoplasia (CIN). VIA, VILI and cytology were positive in 16.9%, 15.6% and 6.1% women, respectively. We found 57 cases of CIN2, 55 of CIN3 and 12 of cervical cancer; 90% of CIN3 and 43% CIN2 cases were positive for p16 overexpression and high-risk HPV infection, indicating a high validity of histological diagnosis. The sensitivity of VIA, VILI and cytology to detect high-grade CIN were 64.5%, 64.5% and 67.7%, respectively; specificities were 84.2%, 85.5% and 95.4%. A high proportion of p16 positive CIN 3 (93.8%) and 2 (76.9%) were positive on cytology compared with visual tests (68.8% and 53.8%, respectively) indicating a higher sensitivity of cytology to detect p16 positive high-grade CIN. However, the immediate availability of the results from the visual tests permits diagnosis and/or treatment to be performed in the same sitting, which can potentially reduce loss to follow-up when women must be recalled following positive cytology. Organizing visual screening services in low-resource countries may facilitate the gradual building of an infrastructure committed to screening allowing the eventual introduction of more sensitive, highly objective, reproducible and affordable human papillomavirus screening tests in future.

Lymphangiosarcoma arising after 33 years within a background of chronic filariasis: a case report with review of literature.

Cutaneous angiosarcoma or lymphangiosarcoma represents an uncommon aggressive tumor known to arise on a background of chronic lymphedema secondary to various etiologies, principally following surgery or irradiation. There have been rarely reported cases of angiosarcoma following infective conditions that eventuate with lymphatic stasis. We report a case of angiosarcoma arising after 33 years within a background of filariasis. Awareness of this association can lead to early diagnosis and appropriate treatment of this potentially fatal malignant tumor.

Immunohistochemical validation of TLE1, a novel marker, for synovial sarcomas.

BACKGROUND & OBJECTIVES: Logistic and financial constraints limit application of several available immunohistochemical (IHC) markers and molecular analysis in every case of synovial sarcoma, diagnosed in our settings. Recently, TLE1 has been recognized as a robust IHC marker for diagnosing a synovial sarcoma. Here, we present IHC features of synovial sarcomas, including TLE1 expression in these cases and in some other tumours. METHODS: Conventional sections from 42 synovial sarcomas (30 retrospective & 12 prospectively diagnosed) were subjected to TLE1 IHC staining, including 21 tumours confirmed with molecular testing. TLE1 immunostaining was graded from 0, 1+, 2+, 3+, with 2+ or 3+ grades interpreted as positive staining. RESULTS: Of the 42 tumours, 26 (61.9%) were of monophasic spindle cell type, 13 biphasic type (30.9%), two (4.7%) calcifying type and remaining one (2.3%) was a poorly differentiated synovial sarcoma. On immunohistochemistry (IHC), tumours were positive for epithelial membrane antigen (EMA) (26/34, 76.4%), cytokeratin (CK)7 (6/10, 60%), CK/MNF116 (6/21, 28.6%), B cell lymphoma 2 (BCL2) (36/37, 97.3%), cluster of differentiation molecule 99 (MIC2) (23/31, 74.1%) and transducin-like enhancer of split 1 (TLE1) (40/42, 95.2%), while negative for CD34 in all 21 tumours, wherever performed. TLE1 was also positive in tumour controls, including schwannomas (5/5, 100%), neurofibromas (2/2, 100%), malignant peripheral nerve sheath tumors (2/12, 17%) and Ewing sarcomas (4/10, 40%). TLE1 sensitivity for diagnosis of synovial sarcomas was 95.2 per cent. Its overall specificity was 63.7 per cent, whereas with regards to tumors forming its closest differential diagnoses, its specificity was 72 per cent. INTERPRETATION & CONCLUSIONS: Although molecular confirmation is the diagnostic gold standard for synovial sarcoma, TLE1, in view of its high sensitivity may be a useful marker within the optimal IHC panel comprising EMA, BCL2, MIC2, CD34 and CK7, especially on small biopsy samples, for substantiating a diagnosis of synovial sarcoma. Awareness of TLE1 expression in other tumours and its correct interpretation are necessary.

Primary extranodal histiocytic sarcoma of lumbar spine.

A 17-year-old male patient presented with lower back pain and weakness of lower limbs. On radiological investigation, a destructive bony lesion involving the third lumbar vertebra was seen associated with soft tissue extension and an extradural component. The lesion was surgically excised in view of the rapidly progressing symptoms. The histologic diagnosis was histiocytic sarcoma. Further investigations did not reveal any other lesion elsewhere. The case is being presented in view of the uncommon occurrence of a primary extranodal histiocytic sarcoma of the lumbar spine, which simulated a primary bone tumor.

Osteosarcoma of the femur mimicking Ewing sarcoma/primitive neuroectodermal tumour on biopsy and metastatic carcinoma on resection.

Osteosarcoma (OS) is known to have several morphological appearances, small cell osteosarcoma and epithelioid osteosarcoma being two well recognized patterns. The former can be mistaken for a Ewing sarcoma/primitive neuroectodermal tumour (ES/PNET), whereas the latter mimics metastatic carcinoma. Herein we present an osteosarcoma in a 17-year-old girl that was diagnosed as an ES/PNET on biopsy; however, the resected specimen revealed a very unusual morphology mimicking a metastatic carcinoma with a sex cord stromal tumour-like pattern.

Radiation Therapy Dose Escalation in Unresectable Ewing Sarcoma: Final Results of a Phase 3 Randomized Controlled Trial.

PURPOSE: Our aim was to assess the effect of radiation therapy (RT) dose escalation on outcomes in surgically unresectable Ewing sarcoma (ES)/primitive neuroectodermal tumor (PNET). METHODS AND MATERIALS: Patients with nonmetastatic unresectable ES/PNET (excluding intracranial/chest wall) receiving vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide chemotherapy, planned for definitive RT, were accrued in this single-institution, open-label, phase 3 randomized controlled trial. Randomization was between standard dose RT (SDRT; 55.8 Gy/31 fractions/5 days a week) versus escalated dose RT (EDRT; 70.2 Gy/39 fractions/5 days a week) with a primary objective of improving local control (LC) by 17% (65%-82%). Secondary outcomes included disease-free survival (DFS), overall survival (OS), and functional outcomes by Musculoskeletal Tumor Society score. RESULTS: Between April 2005 and December 2015, 95 patients (SDRT 47 and EDRT 48) with a median age of 17 years (interquartile range, 13-23 years) were accrued. The majority of patients were male (59%). Pelvis was the most common site of primary disease (n = 60; 63%). The median largest tumor dimension (9.7 cm) and the median maximum standardized uptake value (8.2) on pretreatment fluorodeoxyglucose positron emission tomography-computed tomography were similar. At a median follow-up of 67 months, the 5-year LC, DFS, and OS for the entire cohort was 62.4%, 41.3%, and 51.9%, respectively. The 5-year LC was significantly better in EDRT compared with SDRT (76.4% vs 49.4%; P = .02). The differences in DFS and OS at 5 years (for EDRT vs SDRT) did not achieve statistical significance (DFS 46.7% vs 31.8%; P = .22 and OS 58.8% vs 45.4%; P = .08). There was a higher incidence of Radiation Therapy Oncology Group grade >2 skin toxic effects (acute) in the EDRT arm (10.4% vs 2.1%; P = .08) with excellent functional outcomes (median Musculoskeletal Tumor Society score = 29) in both arms. CONCLUSIONS: EDRT results in improved LC with good functional outcomes without a significant increase in toxic effects. Radiation dose escalation should be considered for surgically unresectable nonmetastatic ES/PNET.

Kaposiform hemangioendothelioma in tonsil of a child associated with cervical lymphangioma: a rare case report.

Kaposiform hemangioendothelioma (KHE) is an uncommon vascular tumor of intermediate malignant potential, usually occurs in the extremities and retroperitoneum of infants and is characterized by its association with lymphangiomatosis and Kasabach-Merritt phenomenenon (KMP) in certain cases. It has rarely been observed in the head and neck region and at times, can present without KMP. Herein, we present an extremely uncommon case of KHE occurring in tonsil of a child, associated with a neck swelling, but unassociated with KMP. A 2-year-old male child referred to us with history of sore throat, dyspnoea and right-sided neck swelling off and on, since birth, was clinicoradiologically diagnosed with recurrent tonsillitis, including right sided peritonsillar abscess, for which he underwent right-sided tonsillectomy, elsewhere. Histopathological sections from the excised tonsillar mass were reviewed and showed a tumor composed of irregular, infiltrating lobules of spindle cells arranged in kaposiform architecture with slit-like, crescentic vessels. The cells displayed focal lumen formation containing red blood cells (RBCs), along with platelet thrombi and eosinophilic hyaline bodies. In addition, there were discrete foci of several dilated lymphatic vessels containing lymph and lymphocytes. On immunohistochemistry (IHC), spindle cells were diffusely positive for CD34, focally for CD31 and smooth muscle actin (SMA), the latter marker was mostly expressed around the blood vessels. Immunostaining for HHV8 was negative and Ki-67 (proliferation marker) displayed focal positivity. Diagnosis of KHE was made. Platelet count was towards lower side of range. Postoperative imaging showed discrete, multiple fluid containing lesions in the right neck that were high on T2-weighed sequences, on magnetic resonance imaging (MRI) and ipsilateral intraoral mucosal growth. Fine needle aspiration cytology (FNAC) smears from neck swelling showed blood, fluid and lymphocytes. Possibility of a coexisting lymphangioma was considered. The patient was offered sclerotherapy and is on follow-up. This case forms the second documented case of KHE at this site, along with its unique association with neck lymphangioma. KHE has distinct histopathological features and can be sorted out from its other differentials like juvenile hemangioma and Kaposi's sarcoma. IHC stains are useful in substantiating a definite diagnosis.

Bone metastasis of glandular cardiac myxoma mimicking a metastatic carcinoma.

Skeletal metastasis from a cardiac myxoma is rare. We describe an extremely unusual case of a cardiac myxoma metastasing to the femur in a 46-year-old female presenting with pain in the right hip. Radiographs showed an expansile lytic lesion with pathological fracture involving the neck and proximal shaft of the right femur. Histology revealed features of cardiac myxoma with heterologous glandular elements, which was initially mistaken for a metastatic mucin-secreting adenocarcinoma.

Rhinosporidiosis isolated to the distal clavicle: a rare presentation clinicoradiologically mimicking a bone tumor.

Rhinosporidiosis is a chronic granulomatous disease caused by Rhinosporidium seeberi, which commonly affects young men and predominantly involves the mucous membranes of the nose, nasopharynx and eyes. Involvement of extranasal sites including bone has been reported, but rarely. We present a case of a 32-year-old farmer, who presented with a non-tender, fixed swelling over his right shoulder. Radiography and CT imaging showed an expansile, lytic, destructive lesion involving the lateral end of the right clavicle with soft tissue extension. The clinicoradiological impression was that of a primary bone tumor. Biopsy and wide excision of the lesion revealed features of rhinosporidiosis. There were no mucocutaneous lesions. Involvement of bone without associated mucocutaneous lesions is exceedingly rare in rhinosporidiosis. Involvement of the clavicle, as seen in the present case, has not been reported in the English language-peer reviewed literature, to the best of our knowledge.

Melanotic neuroectodermal tumor of infancy in thigh of an infant--a rare case report with diagnostic implications.

Melanotic neuroectodermal tumor of infancy (MNTI) is an uncommon tumor of neural crest origin, almost invariably identified in the head and neck region. It is a relatively benign tumor but can recur and rarely metastasize. Herein, a rare case of MNTI in the thigh of an infant is documented. Radiographic imaging showed a sclerotic and lytic lesion in the metadiaphyseal region of the right femur with a soft tissue component. The clinicoradiological impression was of a malignant round cell tumor and osteomyelitis. The patient's urinary vanil mandelic acid (VMA) level was elevated. FNAC smears revealed a tumor with round to polygonal cells, focally containing black melanin pigment. Biopsy and tumor excision revealed a tumor with cells in cords and nests embedded in a fibrocollagenous stroma and showed bone and soft tissue infiltration. On immunohistochemistry, tumor cells displayed immunoreactivity to vimentin, cytokeratin (CK), CK7, CK19, and MIC2, and focal reactivity for synaptophysin and HMB45. Diagnosis of an MNTI was made. The patient underwent induction chemotherapy with extracorporeal radiotherapy, followed by a soft tissue excision that revealed residual tumor. Surgically, free marrow margins were accomplished, and the patient is currently being followed-up. To the best of our knowledge this case is the fifth documented case in the English literature of MNTI in the thigh. The diagnostic and therapeutic implications are discussed.

Phosphaturic mesenchymal tumor with chondromyxoid fibroma-like feature: an unusual morphological appearance.

Phosphaturic mesenchymal tumor (PMT) is a rare and distinctive tumor almost always associated with oncogenic osteomalacia. This tumor is often misdiagnosed due to its widely varied histomorphological spectrum. More recently the term PMT or its variants has been used whatever the histomorphological features. Herein, we present a case of a 32-year-old woman who presented with a 2-year history of oncogenic osteomalacia. The clinical examination failed to detect any tumor. The F-18 FDG PET scan and subsequent MRI revealed a tumor in the soft tissues of the right popliteal fossa. The histological features resembled a chondromyxoid fibroma (CMF), a feature documented only in two cases so far.

Low-grade fibromyxoid sarcoma: a clinicopathologic study of 18 cases, including histopathologic relationship with sclerosing epithelioid fibrosarcoma in a subset of cases.

Low-grade fibromyxoid sarcoma (LGFMS) is an uncommon tumor with diverse histopathologic features. It has been found to be histopathologically and genetically related to hyalinizing spindle cell tumor with giant rosettes. Lately, sclerosing epithelioid fibrosarcoma (SEF) has been identified as another rare variant of fibrosarcoma. Very few studies have addressed the aspect of its histopathologic relationship with LGFMS. The present study was conducted to critically analyze the clinicopathologic features of a series of LGFMS cases, including identification of cases with histopathologic similarity with SEF. During a 7-year period, 18 LGFMS cases were diagnosed in 9 male and 9 female patients, had ages ranging from 10 to 69 years (median, 32.5 years), and were most commonly identified in the lower extremities (8 cases, or 44.4%). Most cases (16, 88.8%) showed "classic" features of LGFMS with mild (13 cases, or 72.2%) to moderate atypia (5 cases) and nil mitosis (12 cases, or 66.6 %). Variable features included whorling tumor growth pattern, small rosettes, perivascular hyalinization, and amianthoid-like collagen, along with epithelioid differentiation and nuclear pseudoinclusions within tumor cells. Four cases (22.2%) with large collagenous rosettes were diagnosed as hyalinizing spindle cell tumor with giant rosettes. Distinct SEF-like areas were observed in 6 cases (33.3%). On immunohistochemistry, consistent vimentin positively reinforced fibroblastic lineage of the tumor. Therapeutically, all 4 of 7 cases with available follow-up details, which underwent wide excisions, have been free of disease at 5 to 61 months. Eight excisions with unclear margins included 3 cases free of disease (24, 36, and 52 months) and 1 case with recurrence and metastasis. Two cases of marginal excision had tumor recurrences, including 1 case that recurred after 10 years. Low-grade fibromyxoid sarcoma is an uncommon sarcoma with diverse histopathologic features. Histopathologic relationship exists between LGFMS and SEF in a few cases. An LGFMS is optimally managed with surgical wide excision and follow-up.

Epithelioid malignant peripheral nerve sheath tumor of the uterine corpus.

Epithelioid variant of a malignant peripheral nerve sheath tumor (MPNST) is a rare sarcoma. Rarer still is its occurrence at uncommon sites like the uterine corpus where an index of suspicion for this diagnosis is extremely low. Herein, we report a rare case of a uterine epithelioid MPNST in a young girl who underwent a total abdominal hysterectomy for a uterine tumor that was initially diagnosed as an undifferentiated sarcoma and whose paraffin blocks were submitted to us for review. Biopsy sections showed a malignant tumor, predominantly composed of polygonal cells, including "rhabdoid" forms with conspicuous mitoses. On immunohistochemistry, tumor cells were diffusely positive for vimentin and S-100 and negative for smooth muscle actin, desmin, myogenin cytokeratin, epithelial membrane antigen, melan A, HMB-45, CD10, glial fibrillary acid protein inhibin, synaptophysin, chromogranin, MIC2, FLI-1, and neuron-specific enolase. Diagnosis of an epithelioid MPNST was offered. The case is presented in view of its rarity and also to highlight the value of immunohistochemistry in objectively identifying unusual sarcomas at uncommon sites.