Renal Leiomyosarcoma: Unraveling the Mysteries of a Rare Malignancy.

Primary leiomyosarcoma is a rare malignant kidney tumor. The diagnosis of this disease is usually made on the basis of histological examination because it lacks specific clinical or radiological characteristics. Differentiation between leiomyosarcoma and sarcomatoid renal cell carcinoma can be challenging because spindle cell morphology is observed in both tumors. Therefore, caution should be exercised when making a diagnosis of primary renal leiomyosarcoma. Both renal sarcoma and sarcomatoid renal cell carcinoma have a worse prognosis, and nephrectomy is the treatment of choice in locally resectable tumors. An example of such a tumor is discussed in relation to its diagnostic challenges. We report a case of a 35-year-old female who presented with a left renal mass. A left radical nephrectomy was performed, and a firm, tan-white, lobulated tumor (14x8x7.5 cm) was present on gross examination. A histological diagnosis of high-grade leiomyosarcoma was made on the basis of histology, positivity for caldesmon and desmin, and negative cytokeratin immunostaining. Sarcomatoid renal cell carcinoma was ruled out based on morphological findings after extensive sampling of the tumor along with negativity for CK, CD-10, and carbonic anhydrase IX immunostaining.

EBV-Associated Smooth Muscle Tumor in the Malar Area of an HIV-Positive Patient: A Case Report.

BACKGROUND: EBV-associated smooth muscle tumors (EBV-SMTs) are rare and typically develop in individuals with a compromised immune system, particularly those who have acquired immunodeficiency syndrome (AIDS) or who have undergone organ transplants. METHODS: We document a case of EBV-SMT in an HIV-positive 25-year-old man. The lesion was incised and assessed histologically and a panel of immune markers were performed. EBV association was demonstrated by in situ hybridization for EBV-encoded RNA (EBER-ISH). RESULTS: Microscopically, the tumor composed of mildly pleomorphic, ovoid to spindled cells with numerous slit-like vascular channels. The tumor cells exhibited diffuse and strong immunoreactivity for smooth muscle actin (SMA) and focal positivity for h-caldesmon. EBER-ISH of the tumor cells revealed strong positive nuclear signals. CONCLUSION: The histopathological features of EBV-SMT do not conform to either benign or malignant SMTs and it has a peculiar predilection to develop at sites unusual for leiomyoma or leiomyosarcoma. The key diagnostic features of EBV-SMT include history of immunosuppression, histologic evidence of primitive and mildly pleomorphic cells maintaining blunt nuclear features in most areas, and positivity for EBER-ISH.

Fine-needle aspiration biopsy diagnosis of histiocyte-rich rhabdomyoblastic tumor (inflammatory leiomyosarcoma): A case report.

Histiocyte-rich rhabdomyoblastic tumor (HRRMT) is an exceedingly rare soft tissue tumor of primitive myogenic differentiation. We report herein a case involving the soft tissue in the left lateral peri-scapular region in a 68-year-old female with a 2-month history of a non-painful soft tissue mass. Ultrasound revealed a solid, ovoid subcutaneous mass lesion that lacked significant internal vascularity. Percutaneous fine-needle aspiration (FNA) biopsy with concomitant core needle biopsy was performed, and a diagnosis of HRRMT was rendered. Cytologic smears were hypercellular, composed of a mixture of foamy histiocytes and a variably cohesive population of epithelioid and plasmacytoid to vaguely spindled cells in cohesive clusters and singly dispersed. Histologic material showed sheets of epithelioid and plasmacytoid to spindled cells with admixed foamy histiocytes with distended, vacuolated cytoplasm. To our knowledge, this is the first reported example of HRRMT evaluated by FNA biopsy.

Primary seminal vesicle epithelioid smooth muscle neoplasm of uncertain biologic potential.

We present the case of a 73-year-old male patient who presented with obstructive urinary symptoms, pelvic pressure, and hematuria. CT imaging revealed a heterogenous prostate enlargement, and MRI demonstrated the mass to be arising from the seminal vesicle. Prostate biopsies showed benign tissue. Surgical excision was completed and pathology revealed it to be an epithelioid smooth muscle neoplasm of uncertain biologic potential. This is only the second known case of such a seminal vesicle tumour. As soft tissue sarcomas of the seminal vesicle emerge in the literature, we may develop a better understanding of their biologic behaviour and prognostic potential.

Myopericytoma Involving Proximal Phalanx of Index Finger: Masquerading as Tenosynovial Giant Cell Tumor - A Case Report.

INTRODUCTION: Myopericytoma (MPC) is an uncommon benign smooth muscle cell neoplasm which frequently arises in lower extremities, sparsely they can be found in upper extremities and head and neck region. Very few case reports are available in the literature documenting hand localization of this tumor. CASE PRESENTATION: In this report, we present a case of 83-year-old male individual with a mass lesion on the proximal phalanx of index finger of the right hand. Recent trivial trauma led the patient to medical assistance. Imaging mimicked Giant cell tumor of tendon sheath due to site of the lesion. The lesion was excised surgically. The final diagnosis of the specimen confirmed by histopathology was MPC, a benign smooth-muscle cell neoplasm. CONCLUSION: MPC is a rare entity; however, definitive diagnosis is often challenging because it mimics some malignant soft-tissue neoplasms. A multidisciplinary approach is required to identify this lesion as being benign and thus define the correct modality of treatment.

Genetic variant of SRF-rearranged myofibroma with a misleading nuclear expression of STAT6 and STAT6 involvement as 3' fusion partner.

Pediatric neoplasms with a myofibroblastic differentiation are frequent in children, in particular myofibroma. Recently, a novel deep soft tissue myofibroblastic neoplasm has been described with high cellularity, a smooth muscle phenotype and SRF-RELA fusion. We report the case of a 15-year-old boy who presented with a tumor of the deep soft tissue of the arm, with overlapping histological features with the recently described SRF-RELA group of myofibromas but differing by the presence of calcifications, a novel SRF-STAT6 fusion transcript and nuclear expression of STAT6. No local recurrence nor distant metastasis was detected at the current follow-up of 29 months. The clinical relevance of this novel fusion requires further investigations.

A case of laparoscopic resection of leiomyosarcoma arising in the mesentery of descending colon: a case report and review of the literature.

Leiomyosarcoma of mesenteric origin is rare and may be managed by laparoscopic surgery as a less invasive procedure, on the condition that the tumor can be resected with a safe margin.

Cutaneous leiomyosarcoma: dermal and subcutaneous.

BACKGROUND AND OBJECTIVES: Leiomyosarcoma of skin (LMS) can be sub-classified on pathology appearances as Dermal or Subcutaneous. The aim of this study was to provide treatment recommendations for these uncommon tumours. METHODS: A retrospective review of all patients with dermal and subcutaneous leiomyosarcoma managed at the Peter MacCallum Cancer Centre, Australia from January 2003 to December 2018 was performed. Eighty-three patients were identified (64 dermal leiomyosarcoma, 19 subcutaneous leiomyosarcoma). RESULTS: Subcutaneous leiomyosarcoma were larger (median size 14 mm dermal, 49 mm subcutaneous, P = 0.01). No patient with a dermal leiomyosarcoma developed metastatic disease compared to 4 of the 19 subcutaneous leiomyosarcoma (5-year overall survivals, 98% and 88%, respectively, P = 0.03). The most common site of metastasis was to the lung. No difference in risk of local recurrence was apparent (5-year recurrence-free survivals were 85% and 78%, respectively, P = 0.17). Adjuvant radiotherapy was used in 16 (25%) dermal leiomyosarcoma patients and 13 (68%) subcutaneous leiomyosarcoma patients (P < 0.001). Local recurrence was uncommon in both tumour subtypes when patients received definitive surgical excision (minimum histological margins of 10 mm as per institutional protocol) regardless of whether radiotherapy was used. The 5-year local recurrence-free survival for dermal leiomyosarcoma treated with radiotherapy was 93% versus 83% without radiotherapy (P = 0.7) and for subcutaneous leiomyosarcoma was 69% and 100%, respectively (P = 0.9). CONCLUSIONS: Dermal leiomyosarcoma have an excellent prognosis, particularly after definitive surgical excision with margins of at least 10 mm. Subcutaneous leiomyosarcoma has poorer outcomes and should be managed by wider excision and considered for adjuvant radiotherapy.

Clinical and Histopathologic Findings of Cutaneous Leiomyosarcoma: Correlation with Prognosis in 12 Patients. / Leiomiosarcoma cutáneo: características clínicas, histopatológicas y correlación pronóstica en 12 pacientes.

INTRODUCTION: Cutaneous leiomyosarcoma is a malignant neoplasm derived from smooth muscle cells. Its low incidence hampers the development of specific protocols for diagnosis and treatment. OBJECTIVES: To describe the clinical and histopathologic characteristics of a series of primary and secondary cutaneous leiomyosarcomas and to determine how these characteristics correlate with prognosis. MATERIAL AND METHODS: We performed an observational, descriptive, retrospective study based on 17 cutaneous leiomyosarcomas in 12 patients diagnosed between January 1, 2000 and December 31, 2015. We recorded demographic data, clinical and histopathologic characteristics, outcome, and response to treatment. RESULTS: We included 5 men and 7 women, all aged more than 50 years at diagnosis. There were 4 cutaneous leiomyosarcomas (23%) in 4 patients, 2 subcutaneous leiomyosarcomas (11.5%) in 2 patients, and 11 skin metastases of leiomyosarcoma (65%) in 6 patients. The most frequently affected sites were the scalp (41%), lower limbs (17%), and trunk (17%). During follow-up, 50% of the cutaneous leiomyosarcomas recurred, 50% of the subcutaneous leiomyosarcomas presented distant metastases, and 83% of the patients with skin metastases of leiomyosarcoma died of their disease. LIMITATIONS: Ours was a retrospective review of a small case series at a single center. CONCLUSIONS: Cutaneous leiomyosarcoma is an uncommon malignant neoplasm. Our approach to diagnosis and therapy must take into account the marked heterogeneity in the prognosis of the various subtypes.

A mesenteric solid tumor with unusual features in a young male: A case report.

The current study presents a mesenteric mesenchymal tumor case, with unusual features in diagnostic imaging and histology. A 16-year-old male was admitted to the hospital with abdominal pain. Computed tomography (CT) revealed an abdominal mass, 2 cm in diameter. The results of contrast-enhanced CT, magnetic resonance imaging and 18F-fluorodeoxyglucose positron emission tomography indicated no specific features suggestive of its histology. Two arteries branching from the superior mesenteric artery were observed feeding the hypervascular tumor. After endoscopic and other laboratory findings revealed no additional lesions, the lesion was diagnosed as a primary mesenteric tumor. As the possibility of malignancy and future bleeding from this tumor could not be ruled out, a resection of the tumor was performed. During the surgery, the tumor, which was well circumscribed and hypervascular, was located in the mesentery of the jejunum. The resected tumor did not exhibit typical histological characteristics, and was labeled as 'myxoid smooth muscle neoplasm of uncertain biologic potential'. At 2 years after surgery, the patient remained well without evidence of recurrence. As primary mesenteric tumors are rare, particularly in young patients, it is considered important that this type of unusual tumor be included in the differential diagnosis for mesenteric tumors.

Leiomyosarcoma of the Wing in a Vieilott's Fireback Pheasant (Lophura rufa).

A 15-year-old, female Vieilott's fireback pheasant (Lophura rufa) presented with a 2-day history of a drooping right wing. Examination revealed severe soft tissue swelling in the area extending from the right shoulder to the humeral-radio-ulnar joint with associated bruising and feather loss. Results of a complete blood cell count revealed marked heterophilia and lymphocytosis, and results of serum biochemical analysis showed severe increases in creatine kinase and aspartate aminotransferase activities, hypoproteinemia, and hypoalbuminemia. Radiographs revealed osteolytic lesions of the right humerus with pathologic fractures and circumferential soft tissue swelling. Although surgical wing amputation was successful, the bird died the next day while being treated. The mass was diagnosed histologically and immunohistochemically as a leiomyosarcoma. This is the first neoplasia of any kind reported in this species, to our knowledge, and one of the very few reports of smooth muscle neoplasms affecting the limb of a bird.

[Atypical intradermal smooth-muscle neoplasm]. / Tumeur musculaire lisse atypique dermique.

BACKGROUND: We report herein a case of atypical intradermal smooth-muscle neoplasm. PATIENT AND METHODS: A 58-year-old man presented with a painless pinkish-white chest nodule ongoing for two years. Histopathology revealed a proliferation of intradermal smooth-muscle cells. Some atypia and 5 mitoses were seen in the most mitotic fields. The histopathologist suggested a diagnosis of "atypical intradermal smooth-muscle neoplasm". DISCUSSION: Atypical intradermal smooth-muscle neoplasm is part of a spectrum extending from skin leiomyoma to leiomyosarcoma. The prognosis consists chiefly in risk of local recurrence. The terminology is not currently accepted by WHO but nevertheless offers an alternative to inappropriate diagnosis of sarcoma, which carries psychological and social impact.

Disseminated peritoneal leiomyomatosis postmorcellated resection of uterine leiomyomatous tissue.

In a retrospective review, we identified six cases of disseminated peritoneal leiomyomatosis (DPL) that occurred after resection for uterine leiomyoma(ta) using a morcellation procedure between 2010 and 2016. DPL occurred in less than 1% of all patients who underwent a prior hysterectomy with morcellation, and DPL never occurred without having underwent such a resection. The median age of women at the time of their original resection of uterine tissue was 38.6 years; the median time interval until resection of DPL after the primary morcellation procedure was 73 months and the median age was 48 years. At the time of DPL resection, a median of 6.5 individual lesions was present per patient, with each lesion having a median size of 1.2 cm in the greatest dimension. The most common peritoneal sites of involvement included the sigmoid colon serosa, right pelvis/pelvic side wall, and anterior abdominal parietal peritoneum. The same parameters are described for previously reported cases of DPL in the literature developing after a morcellated resection of uterine leiomyoma(ta). The use of morcellating hysterectomy specimens with leiomyomata may lead to the development of DPL by seeding, may involve numerous peritoneal sites, and often presents 2 years after the original resection.

S100A6 expression in cutaneous smooth muscle neoplasms.

The S100A6 protein is expressed in a variety of tissues and distinct staining patterns in S100A6 immunohistochemistry may be useful in the differential diagnosis of difficult lesions. We evaluated the staining pattern of the S100A6 antibody in 22 cases each of pilar leiomyoma (LM), angioleiomyoma (ALM), and cutaneous leiomyosarcoma (LMS). S100A6 labeled both the nucleus and cytoplasm of myocytes in positive cases. About 64% of LM and 86% ALM had positive staining to the S100A6 antibody but predominantly in a weak staining pattern. In contrast, 95% of the LMS exhibited moderate to strong staining with the S100A6 antibody. The difference in the frequency of positive cases was statistically significant in the LM vs LMS comparison (p = 0.025), but we found intensity of staining to be of greatest practical utility. Analysis between the groups taking in to consideration differences in intensity of staining using the nonparametric rank sum (Mann-Whitney U test) demonstrated that there was a statistically significant difference between LM and LMS and between ALM and LMS. Weak or absent S100A6 staining supports a diagnosis of LM, whereas strong positive staining supports a diagnosis of LMS.

Incidental gynecologic neoplasms in morcellated uterine specimens: a case series with follow-up.

Laparoscopic hysterectomy with morcellation (LHM) is considered a safe and less invasive alternative to other hysterectomy techniques by shortening postoperative hospital stay and patient recovery. Sparse incidental gynecologic neoplasms after LHM have been reported; however, the frequency and subsequent follow-up have not been systematically investigated in a large case series. We aimed to determine the frequency and types of incidental findings after LHM with clinical outcomes. An electronic chart review was conducted searching all cases of LHM performed within 5 years to determine the incidence of unexpected gynecologic neoplasms and subsequent peritoneal disease. Patient demographics, prior preoperative investigation, and subsequent follow-up were investigated. For comparison, the overall frequency of pertinent uterine neoplasms was noted during the study period. Of the 352 cases of LHM identified, 3 harbored unsuspected malignancies, an incidence of 0.9%. Four variant smooth muscle tumors (1.1%) and 5 benign non-smooth muscle neoplasms (1.4%) were identified at the time of initial morcellation. Two cases of subsequent peritoneal "implanted" leiomyoma were identified (0.6%). Of malignant or atypical mesenchymal neoplasms diagnosed at our institution during the study period, 8.6% were diagnosed in a morcellated specimen. There is a clinically important risk of occult malignant or atypical neoplasms in morcellated uterine specimens. Proper pathologic evaluation of malignant or atypical uterine neoplasms is limited when a uterus is morcellated. Patients undergoing morcellation procedures are also potentially at risk for dissemination of disease. Clinicians and patients should be aware of these risks when discussing surgical options for hysterectomy.

Leiomyosarcoma of the skin: clinical, histopathologic, and prognostic factors that influence outcomes.

BACKGROUND: Superficial leiomyosarcoma (LMS) is a rare tumor with important clinical, pathologic, and treatment features. Previous LMS studies have included few patients, included minimal follow-up, and typically combined the superficial and subfascial (deep) forms. OBJECTIVE: We sought to characterize clinical features, effectiveness of treatment approaches, and long-term outcomes for LMS stratified by depth of invasion. METHODS: In all, 71 cases of primary superficial LMS, 48 dermal and 23 subcutaneous (mean follow-up of 8 years), were examined and clinical, histopathologic, and treatment factors reported. RESULTS: Tumor size and subcutaneous classification correlated with greater likelihood of metastasis and death at 5 years. When superficial LMS metastasizes, other skin sites are the most common distant location. Treatment with wide local excision with minimum 1-cm margins showed statistically lower rates of recurrences and metastasis compared with excision with narrow surgical margins. Fourteen cases of Mohs micrographic surgery had no recurrences or metastases. Five cases of dermal LMS metastasized, 2 of which resulted in death. LIMITATIONS: This study is a retrospective review of a relatively small number of patients. CONCLUSION: LMS can metastasize and warrants surgical intervention and long-term follow-up. Wide local excision, and Mohs micrographic surgery in particular, appear to provide the best management approach for definitive treatment.

Uterine smooth muscle tumors of uncertain malignant potential (STUMP): pathology, follow-up and recurrence.

The term smooth uterine muscle of uncertain malignant potential (STUMPs) indicates a group of uterine smooth muscle tumors (SMTs) that cannot be diagnosed unequivocally as benign or malignant. Diagnosis, surgical management, and follow-up of this neoplasm remain controversial, especially in pre-menopausal women with fertility desire, due to the non aggressive behaviour and prolonged survival rate when compared to leiomyosarcomas. However, recurrence is estimated between 8.7% and 11% and may include delayed-recurrences. We reported five cases of uterine masses treated by surgical procedure diagnosed as STUMP on final pathology. Four patients underwent a total abdominal hysterectomy with or without salpingo-oophorectomy. One patient underwent excision of uterine mass and subsequent total abdominal hysterectomy plus bilateral salpingo-oophorectomy after the diagnosis of STUMP. All patients in our study remained recurrence-free to date (with a follow up period ranging from 6 to 81 months). Based on our experience and in consideration of the lack of consensus regarding the malignant potential, diagnostic criteria, gold-standard treatment and follow-up, we believe that close multidisciplinary management is mandatory in the event of STUMP. We suggest that gynaecologist, dedicated pathologist (with high level of expertize in gynaecological pathology) and oncologist should work as a team in the counselling and management of this neoplasm from detection till completion of follow up. Furthermore, we recommend immunohistochemistry to investigate the overexpression of p16 and p53 in order to identify the cohort of patients at increased risk of recurrence who may benefit from more aggressive surgical-oncological strategies.

Accuracy of core needle biopsy for musculoskeletal tumours.

PURPOSE: To evaluate the sensitivity and specificity of core needle biopsy in determining musculoskeletal tumours in our hospital. METHODS: Records of 134 patients who underwent core needle biopsy followed by definitive surgery were retrospectively reviewed. Results of the core needle biopsy were compared with those of the final histology. Histology was classified into benign versus malignant, and bony versus soft-tissue lesions. The sensitivity and specificity of core needle biopsy were calculated. RESULTS: Based on final histology, there were 33 bone tumours (3 benign and 30 malignant), 74 soft-tissue tumours (6 benign and 68 malignant), 11 schwannomas (7 benign and 4 malignant), and 16 inflammatory/necrotic (benign) lesions. For 118 (88%) tumours, the biopsy results matched the final histological results. For 7 tumours, biopsy results were non-diagnostic, as the amount of tissue obtained was insufficient. For 9 tumours, biopsy results did not match the final histological results; 5 considered benign but turned out to be malignant, one considered malignant but turned out to be benign, and 3 were correctly identified as malignant but incorrectly subtyped. The sensitivity and specificity of core needle biopsy were 95% (97/102) and 97% (31/32), respectively, assuming that the 7 non-diagnostic tumours were correctly diagnosed. CONCLUSION: Core needle biopsy is an accurate and reliable diagnostic tool for musculoskeletal tumours if performed by skilled persons and adequate tissue is obtained.

Oral alveolar rhabdomyosarcoma: a case report with immunohistochemical analysis.

Rhabdomyosarcomas are among the most common soft-tissue tumors in children. These tumors are derived from mesenchymal tissue with a tendency toward myogenic differentiation that probably originates from immature and highly invasive satellite cells associated with the embryogenesis of skeletal muscle. Some of these tumors are associated with high rates of recurrence and metastasis. The diagnosis is made by microscopic analysis and auxiliary techniques such as immunohistochemistry, electron microscopy, cytogenetic analysis, and molecular biology. We report a case of 28-year-old man who presented with a painless progressive swelling of gingiva since 3 months, which was gradually increasing in size without any systemic symptoms or signs of any metastatic spread. An incisional biopsy was done and histopathology reported an alveolar variant of rhabdomyosarcoma. Immunohistochemistry with panel of markers was done which showed positivity for CD99, vimentin and negative for desmin and myogenin. So the characteristic immunohistological expression was negative in present case. Hence we conclude that haematoxylin and eosin morphology and ultrastructure are needed to classify rhabdomyosarcoma and immunohistochemistry act only as an auxiliary.