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.

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.

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.

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.

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.

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.

Grossing and reporting of bone tumor specimens in surgical oncology: Rationale with current evidence and recent updates.

Primary bone tumors, including sarcomas, are rare tumors and require a multidisciplinary approach, including inputs from a radiologist, pathologist, medical oncologist, and surgical and radiation oncologist, for optimal management. Over the years, there has been a paradigm shift toward the treatment of bone sarcomas, from radical resections to conservative surgical procedures, to achieve improved clinical and functional outcomes. This has led to receiving and processing various types of specimens in orthopedic oncopathology. Grossing and reporting of bone tumors require expertise. This review focuses upon the types of biopsies, grossing techniques of various specimens in orthopedic oncology and reporting, with rationale and recommendations from pathologists, actively involved in reporting and pursuing a special interest in bone tumors, based on current evidence. Furthermore, there is a section on some of the updates in the diagnosis of bone tumors, based on the recent fifth edition of the World Health Organization classification of tumors of soft tissues and bone.

Grossing and reporting of a soft tissue tumor specimen in surgical pathology: Rationale, current evidence, and recommendations.

Soft tissue tumors, including sarcomas are complex and diagnostically challenging tumors. This is as a result of their heterogeneity and overlapping clinicopathological, immunohistochemical and also molecular features, the latter to some extent. More than 80 types of sarcoma have been described. Current management, which is best offered at centers with active multidisciplinary care, is based on balancing oncologic and functional outcomes in such cases. This has transcended into the types of specimens received for grossing these rather uncommon tumors. Over the years, diagnostic specimens have reduced in their sizes from, open biopsies to core needle biopsies. These specimens need to be adequately and judiciously triaged for ancillary techniques, such as molecular testing. Conservative surgeries have led to resected specimens for marginal assessment. Lately, post neoadjuvant (chemotherapy or radiation therapy)-treated resection specimens of soft tissue sarcomas are being submitted for surgical pathology reporting. This article focuses on the grossing of soft tissue tumors, including sarcomas, in terms of types of specimens, grossing techniques including rationale, tissue triage, reporting, and recommendations from the surgical pathologists actively engaged in reporting musculoskeletal tumors, based on current evidence.

Epithelioid variant of a pleomorphic liposarcoma displaying arborizing vascular arrangements on cytology smears: a case report of an interesting cytomorphologic pattern in an uncommon tumor.

BACKGROUND: There is limited documentation on cytologic features of liposarcomas, especially pleomorphic liposarcomas (PLPSs), in view of their rarity. CASE: We present cytomorphologic features of an uncommon case of epithelioid variant of a PLPS appearing as a recurrent mass in a young adult man. Fine needle aspiration cytology smears displayed prominent arborizing vasculature with numerous lipoblasts with well-defined vacuolated cytoplasm, indenting the nuclei. In addition, mitoses were conspicuously noted. Biopsy from the scar recurrence and following wide excision showed a multinodular tumor with solid arrangement of tumor cells, separated by delicate vessels. Cells displayed well defined cytoplasmic borders, including several lipoblasts and focal areas of spindly sarcomatous differentiation. Typical and atypical mitoses were conspicuously seen and myxoid areas were absent. Immunohistochemistry showed diffuse positivity for vimentin and S-100; cytokeratin showed weak, focal cytoplasmic positivity. CD34 highlighted the delicate vasculature on tissue sections. Diagnosis of an epithelioid variant of a PLPS was finally offered. CONCLUSION: This rare case describes cytomorphologic features of an epithelioid variant of a PLPS, including prominent arborizing vasculature, a pattern that has invariably been described in a myxoid liposarcoma. Additionally, presence of numerous lipoblasts and mitoses led to the diagnosis of this rare variant.

Morphologic spectrum, immunohistochemical analysis, and clinical features of a series of granular cell tumors of soft tissues: a study from a tertiary referral cancer center.

A granular cell tumor (GCT) is relatively uncommon and objectively diagnosed with neural markers on immunohistochemistry (IHC). Recent studies have described additional markers for a GCT. Herein, we present morphologic spectrum of 12 GCTs of soft tissues and skin, including 10 benign and 2 malignant subtypes with an optimal diagnostic IHC panel. Eleven cases occurred in women and 1 in a man, with a mean age of 45.5 years. Six cases occurred in soft tissues and skin of extremities, 4 in the breast soft tissues, and 1 case each in the back and preauricular region, respectively. Cytologic smears in 2 cases displayed polygonal cells with abundant, eosinophilic, granular cytoplasm. On histopathology, all cases invariably revealed a nonencapsulated infiltrating tumor comprising groups and nests of granular cells with vesicular nuclei. In 5 cases, granular cells were noted in close proximity to the nerves. Two malignant GCTs revealed necrosis, mitoses, and nuclear atypia. Immunohistochemistry in 10 cases (83.3%) showed diffuse S-100 positivity in all 7 benign and 2 malignant cases: cytoplasmic CD68 positivity (all 10 cases) and membranous vimentin staining (all 4 cases). Inhibin showed cytoplasmic positivity in 3 of 6 cases. A single malignant GCT showed focal desmin reactivity. All were surgically managed. A GCT is a discrete tumor entity and can be identified from other granular lesions by its proximity to nerves and objective identification with diffuse S-100 positivity, CD68 positivity, and membranous vimentin positivity that form an optimal IHC panel in limited resource settings, irrespective of benign or malignant types.

Metastatic adenocarcinoma presenting as an inguinal hernia: a case report and review of literature.

A 61 year old man presented with an inguinal hernia with no other significant symptoms. Histopathological examination of the hernial sac revealed metastatic deposits of a mucin secreting adenocarcinoma which was confirmed by subsequent tumor marker levels. Patient was put on chemotherapy for disseminated adenocarcinoma and is tolerating it well. This case emphasizes the need to carefully examine all hernial sacs received for pathological examination.

Epithelioid sarcoma of the foot with subsequent lesion in hand: metastatic lesion or second primary?

Epithelioid sarcomas (ES) are rare tumors of soft tissue that have a propensity to occur in the extremities. Epithelioid sarcomas are known to metastatise to draining lymph nodes and commonly to the lungs. Herein, a case of epithelioid sarcoma which recurred in an unusual site namely the distal phalanx of left middle finger, six months post amputation of the primary lesion in the left foot is being reported. The ipsilateral inguinal lymph node showed metastatic deposits. The tumor at both these sites had similar histology and an identical immunohistochemical (IHC) pattern showing reactivity to cytokeratin (CK), epithelial membrane antigen (EMA), vimentin (Vim) and CD34. This case is presented to record an unusual occurrence of ES in the distal phalanx of middle finger with an ES of foot. The metastasis of ES to the distal acral bones has not been documented till date.

Clinicopathologic features of four rare types of chordomas, confirmed by brachyury immunostaining.

BACKGROUND: A wide clinicopathologic spectrum of a chordoma exists. Brachyury constitutes as its most useful diagnostic immunohistochemical (IHC) marker. METHODS: During a 7-year-period, 4 unusual histopathologic types of chordomas were identified. Immunohistochemistry was performed by polymer technique. RESULTS: Clinicopathologic features of the 4 cases are as follows: Cases 1 and 2: Two tumors occurred in the sacrococcygeal and lumbosacral regions of a 42-year-old male and a 34-year-old female, respectively. Histopathologic examination showed areas of classical chordoma; juxtaposed to a high-grade, spindle cell sarcoma. By IHC, cytokeratin (CK), epithelial membrane antigen (EMA), S-100 protein, and brachyury were found to be distinctly positive in the differentiated chordomatous areas. Both these cases were diagnosed as dedifferentiated chordomas. The first patient, postresection and adjuvant radiation therapy (RT), died after 14 months of therapy. Case 3: A 58-year-old male presented with pain in his sacral region and urinary incontinence. Imaging disclosed a sacral mass. Histopathologic examination showed physaliphorous cells intimately admixed with, markedly pleomorphic cells, scattered mitotic figures, and focal tumor necrosis. By IHC, the tumor cells were positive for CK, AE1/AE3, S-100 protein, brachyury, and INI1/SMARCB1. The diagnosis of a poorly differentiated chordoma was offered. Despite surgical resection and adjuvant RT, the patient died within 18 months. Case 4: A 58-year-old male presented with a soft tissue lesion in his left leg. Histopathologic examination showed physaliphorous cells, embedded in a myxohyaline stroma. By IHC, the tumor cells were positive for EMA, S-100 protein, brachyury, and INI1. Diagnosis of an extra-axial, soft tissue chordoma was offered. CONCLUSIONS: These four unusual chordomas, confirmed by brachyury immunoexpression, constitute as one of the first such documentation from our country, revealing a wide clinicopathologic spectrum of chordomas. Dedifferentiated and poorly differentiated chordomas are associated with an aggressive clinical course. Further diagnostic implications are discussed herewith.

Clinicopathological Features of a Series of 27 Cases of Post-Denosumab Treated Giant Cell Tumors of Bones: A Single Institutional Experience at a Tertiary Cancer Referral Centre, India.

Giant cell tumor of bone (GCTB) is mostly a benign tumor, but associated with recurrences and metastasis. Lately, denosumab is being utilized in the treatment of certain GCTBs. Twenty-seven tumors, analyzed in the present study, occurred in 16 males and 11 females (M: F = 1.45:1), in the age-range of 16 to 47 years (mean = 29.5, median = 29). Most tumors were identified in the tibia(6) and femur(6), followed by the humerus(3), radius(3), pelvis(3), fibula(3), sacrum(1), metacarpal(1) and metatarsal(1) bones. There were 18(66.6 %) primary and 9(33.3 %) recurrent tumors. Exact tumor size (19 cases) varied from 3.7 to 15 cm (mean = 7.8, median = 6.4). Eight of the 19 tumors (42.1 %) had size more than or equal to 8 cm. On histopathologic examination of post-denosumab treated specimens, more than half cases (15)(55.5 %) revealed complete absence of osteoclast-like giant cells (OCLGs) and 12 cases revealed residual OCLGCs. In addition, there was replacement by fibro-osseous tissue, including reactive woven bone or osteoid in most cases, followed by variable amount of spindle cells, hyalinisation, fibrosis and chronic inflammatory cells, including lymphocytes, macrophages and plasma cells. Post-treatment follow-up (25 cases, 92.5 %), over 7-27 months duration (median = 18), revealed 20 cases continuously disease-free. Five patients developed recurrences at 9, 12, 13, 14 and 18 months, respectively. Out of these, who underwent repeat surgical intervention, 4 patients are alive with no evidence of disease and a single patient, planned for a second surgery, is alive-with-disease. Denosumab was mostly offered to patients with large sized, borderline salvageable tumors, in order to decrease the morbidity of index surgical procedure, that led to disappearance of OCLGCs in most cases. Post-denosumab treated GCT cases appear as low grade osteosarcomas on histopathologic examination, but lack the clinical behaviour of an osteosarcoma, therefore may be considered as pseudo malignant bony lesions.

CD10 in diffuse uterine leiomyomatosis: a case report along with a few comments on histogenesis.

Diffuse uterine leiomyomatosis (DUL) is a rare entity with an unknown etiopathogenesis. A 24 years old female presented with abdominal discomfort and menorrhagia. Clinical and ultrasonographic examination revealed an enlarged uterus. The hysterectomy specimen showed a symmetrically enlarged uterus with a bosselated external surface. The cut surface showed multiple nodules of varying sizes diffusely involving the myometrium. Microscopically, the nodules were leiomyomas of varying degrees of cellularity. Some of the leiomyomas showed an increased vascularity either in the form of congeries of blood vessels with a lobular arrangement or occasionally as foci of 2-3 vessels. The vessels were surrounded by whorls of spindle cells. On immunohistochemistry the leiomyomas expressed vimentin, smooth muscle actin (SMA), desmin and CD10: the cells whorling around the blood vessels expressed vimentin, SMA and focally desmin and were negative for CD10 and HMB-45. The aim of this paper is to document that CD10 is expressed in diffuse uterine leiomyomatosis and discuss the histogenesis of DUL.

Angiomatoid fibrous histiocytoma: Clinicopathological spectrum of five cases, including EWSR1-CREB1 positive result in a single case.

BACKGROUND: Angiomatoid fibrous histiocytoma (AFH) is an unusual soft tissue tumor (STT), characterized by recurrences, but rarely metastasis. Later, certain molecular signatures have been identified underlying this tumor, which at times, is either underdiagnosed as a benign vascular tumor, or over diagnosed as a high-grade pleomorphic sarcoma, including a malignant fibrous histiocytoma. MATERIALS AND METHODS: Over a 14-year-period, five diagnosed cases of AFH were analyzed. RESULTS: Five tumors occurred in three males and two females, over a wide age-range (median = 21, mean = 30 years); mostly in the extremities (4) (80%). Microscopically, most tumors were circumscribed, comprising large, blood-filed spaces with surrounding histiocytic cells and a "cuff" of lymphoplasmacytic cells. Three tumors revealed solid growth pattern with polygonal to spindle cells, including myxoid matrix in one of these tumors. On molecular analysis, this tumor exhibited EWS-CREB transcript. Immunohistochemically, various tumors were positive for CD68 (n = 2/2), epithelial membrane antigen (n = 3/4), CD99/MIC2 (n = 2/3), and desmin (n = 1/4). All tumors were surgically excised. On follow-up (n = 2), a single patient, who underwent wide-excision was free-of-disease (24 months), while another patient had a recurrence 4 months post tumor excision. CONCLUSIONS: This forms as the first documented series on clinicopathological features of AFH, a rare STT, from our country. Significant clinicopathological features include younger age, extremities as commonest site and histopathological appearance of blood-filled spaces with surrounding "cuff" of histiocytic cells and lymphocytes. Tumors with unusual histopathological tumor patterns require molecular confirmation. Surgical resection remains the treatment mainstay.