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Cell Mar 2024Proprioception tells the brain the state of the body based on distributed sensory neurons. Yet, the principles that govern proprioceptive processing are poorly...
Proprioception tells the brain the state of the body based on distributed sensory neurons. Yet, the principles that govern proprioceptive processing are poorly understood. Here, we employ a task-driven modeling approach to investigate the neural code of proprioceptive neurons in cuneate nucleus (CN) and somatosensory cortex area 2 (S1). We simulated muscle spindle signals through musculoskeletal modeling and generated a large-scale movement repertoire to train neural networks based on 16 hypotheses, each representing different computational goals. We found that the emerging, task-optimized internal representations generalize from synthetic data to predict neural dynamics in CN and S1 of primates. Computational tasks that aim to predict the limb position and velocity were the best at predicting the neural activity in both areas. Since task optimization develops representations that better predict neural activity during active than passive movements, we postulate that neural activity in the CN and S1 is top-down modulated during goal-directed movements.
Topics: Animals; Proprioception; Neurons; Brain; Movement; Primates; Neural Networks, Computer
PubMed: 38518772
DOI: 10.1016/j.cell.2024.02.036 -
Cureus Feb 2024Background and objective Rhabdomyosarcoma (RMS) is a rare and malignant mesenchymal tumor characterized by skeletal muscle differentiation. While it is a common soft...
Background and objective Rhabdomyosarcoma (RMS) is a rare and malignant mesenchymal tumor characterized by skeletal muscle differentiation. While it is a common soft tissue sarcoma in children, its incidence significantly decreases with advancing age, rendering it exceptionally rare in individuals aged more than 45 years. This study aimed to shed light on the clinicopathological diversity and subtypes of RMS, thereby providing a comprehensive overview for enabling diagnostic precision and therapeutic strategies in treating this infrequently encountered malignancy in adults. Methodology This was a hospital-based cross-sectional study conducted in the Department of Pathology. Patients who were diagnosed with RMS over a period of three years were included in the study. The demographic features such as age and sex and aspects related to the tumor site, size, subtypes of RMS, and immunohistochemical expression were studied. Results A total of 14 cases were included in our study. The age at diagnosis ranged from four months to 65 years with a male-to-female ratio of 1:2.5. The sites of presentation were head and neck, trunk, pelvis, genitourinary tract, and retroperitoneum. The histological types were embryonal, alveolar, pleomorphic, and mixed and spindle cell types. The tumor cells were positive for immunohistochemistry markers desmin, MyoD1, and vimentin. Conclusion This study delved into the clinicopathological intricacies of RMS, offering comprehensive insights into its diverse subtypes. Our findings underscore the unique presentation of RMS in adults, with trunk and genitourinary tracts emerging as primary sites and alveolar and pleomorphic RMS observed as the predominant histological subtypes. Furthermore, the study sheds light on rare subtypes with distinct anatomical distributions.
PubMed: 38500901
DOI: 10.7759/cureus.54341 -
Surgical Case Reports Mar 2024Inflammatory myofibroblastic tumor (IMT) of the stomach is an uncommon mesenchymal neoplasm. We present a case of gastric submucosal tumor (SMT) where the final...
BACKGROUND
Inflammatory myofibroblastic tumor (IMT) of the stomach is an uncommon mesenchymal neoplasm. We present a case of gastric submucosal tumor (SMT) where the final diagnosis was IMT.
CASE PRESENTATION
A 69-year-old man presented with a 24-mm SMT on the posterior wall of the middle third of the stomach that was detected by screening upper gastrointestinal endoscopy. Abdominal contrast-enhanced computed tomography showed that the tumor was well-enhanced. Although endoscopic ultrasonography-guided biopsy was performed, the histological diagnosis was not confirmed preoperatively. Since the tumor was clinically suspected to be a gastrointestinal stromal tumor, we performed gastric wedge resection by laparoscopic-endoscopic cooperative surgery. Pathologically, proliferative spindle cells with a positive reaction for smooth muscle actin, negativity for c-kit, desmin, s-100, CD34, STAT-6, β-catenin and anaplastic lymphoma kinase 1 were identified. Hence, the tumor was finally diagnosed as an IMT originating from the stomach.
CONCLUSIONS
When an SMT of the stomach is identified, the possibility of gastric IMT should be considered.
PubMed: 38485843
DOI: 10.1186/s40792-024-01844-7 -
Croatian Medical Journal Feb 2024Uterine leiomyosarcoma (uLMS) is a rare but aggressive cancer with a high metastatic potential and an unfavorable prognosis. A 54-year-old woman with a history of... (Review)
Review
Uterine leiomyosarcoma (uLMS) is a rare but aggressive cancer with a high metastatic potential and an unfavorable prognosis. A 54-year-old woman with a history of uterine fibroids clinically presented with a painless, palpable left breast mass measuring 20 mm. A core biopsy of the breast mass demonstrated a cellular spindle cell neoplasm (a potentially malignant smooth muscle neoplasm; B4). A wide local breast-mass excision was performed, revealing grade-2 leiomyosarcoma. A re-review of the uterine fibroids revealed that the largest one (200 × 130 mm), initially diagnosed as symplastic leiomyoma, was morphologically identical to the breast lesion. Additional diagnostic work-up revealed multiple liver and pulmonary metastases with a suspected metastatic sclerotic lesion in the L3 projection. The patient was subsequently treated with chemotherapy protocol for metastatic uLMS. The latest follow-up in September 2023 confirmed stable disease. This case highlights the importance of considering unusual metastatic patterns when evaluating breast masses, particularly in patients with a history of non-specific uterine conditions. Comprehensive diagnostic work-up, including imaging and histopathologic examinations, is crucial for an accurate diagnosis of uLMS and appropriate treatment selection. Further studies are needed to better understand the underlying mechanisms and optimal management strategies for metastatic uLMS.
Topics: Female; Humans; Middle Aged; Leiomyosarcoma; Leiomyoma; Antineoplastic Combined Chemotherapy Protocols; Liver; Lung Neoplasms
PubMed: 38433512
DOI: 10.3325/cmj.2024.65.51 -
Cureus Feb 2024Nodular fasciitis (NF) is a benign, self-limiting condition that is often misdiagnosed due to its resemblance to other lesions. Although NF is common, its occurrence in...
Nodular fasciitis (NF) is a benign, self-limiting condition that is often misdiagnosed due to its resemblance to other lesions. Although NF is common, its occurrence in the oral cavity is rare and particularly challenging for both clinicians and pathologists. To date, no case has been reported in the retromolar area of the oral cavity.A 49-year-old male patient presented with a painless, rapidly growing, firm nodule in the right retromolar area. Histopathological examination revealed spindle cell proliferation with characteristics of NF and immunohistochemical analysis confirmed the diagnosis. The lesion was treated by conservative surgical excision, without recurrence at a one-year follow-up. In the current case, 54 cases of oral nodular fasciitis (ONF) have been documented. The majority of ONF-affected individuals are in their 40s, with a 1:1 male-to-female ratio. The buccal mucosa was the most commonly involved site followed by the tongue and labial mucosa. Histopathologically, the most prominent features were the proliferation of uniform spindle-shaped cells within a myxomatous and/or fibrotic background. A positive smooth muscle actin (SMA) stain was a consistent finding. Complete local excision remains the preferred treatment method, and no recurrences have been reported. This report underscores the importance of considering NF in the differential diagnosis of oral spindle cell lesions and emphasizes the need for a comprehensive evaluation to guide appropriate management.
PubMed: 38405650
DOI: 10.7759/cureus.54803 -
Indian Journal of Pathology &... Nov 2023Angioleiomyoma is a benign neoplasm that arises from vascular smooth muscle cells. Angioleiomyoma of the endometrium is very uncommon. The differential diagnoses of this...
Angioleiomyoma is a benign neoplasm that arises from vascular smooth muscle cells. Angioleiomyoma of the endometrium is very uncommon. The differential diagnoses of this entity are myopericytoma, angiomyofibroblastoma, endometrial stromal tumor, and perivascular epithelioid cell tumor. 31-year-old and 45-year-old patients presented with heavy menstrual bleeding, lower abdomen pain, and dysmenorrhea. Perspeculum and radiological investigations showed an endometrial polyp. They underwent diagnostic hysteroscopy, polypectomy, and endometrial biopsy. Polypectomy specimens of both cases revealed polypoidal lesions lined by the endometrium. The core of the polyp was arranged in long intersecting bundles of spindle cells and interconnecting anastomotic patterns with many intervening thick-walled blood vessels. These spindle cells have oval and cigar-shaped nuclei, fine chromatin, and a moderate amount of eosinophilic cytoplasm, resembling smooth muscle cells. These smooth muscle cells of the vessel wall were merging with the adjacent walls of the blood vessel. There was no nuclear atypia or necrosis. The mitotic rate was 0-1/10 HPF. Focal areas of hyalinization and adipocytic components were noted in one case. The endometrial glands did not show intraepithelial or invasive neoplasia. On immunohistochemistry (IHC), these spindle cells were diffuse and strongly immunopositive for SMA and Desmin. CD34 highlighted the endothelial lining of the prominent thick-walled blood vessels. By correlating with histomorphology and IHC positivity, a diagnosis of angioleiomyomatous polyp of endometrium was rendered. We report two uncommon cases of angioleiomyoma of the endometrium and discuss the differential diagnosis and literature review.
PubMed: 38394403
DOI: 10.4103/ijpm.ijpm_108_23 -
Heliyon Feb 2024Previous work suggests that proprioceptive information from ankle and hip are crucial in maintaining balance during upright standing; however, the contribution of these...
BACKGROUND
Previous work suggests that proprioceptive information from ankle and hip are crucial in maintaining balance during upright standing; however, the contribution of these proprioceptive information during stepping balance recovery in not clear. The goal of the current study was to assess the role of ankle and hip proprioceptive information on balance recovery performance by manipulating type 1a afferent in muscle spindles using vibratory stimulation.
METHODS
Twenty healthy young participants were recruited (age = 22.2 ± 2.7 years) and were randomly assigned to balance recovery sessions with either ankle or hip stimulation. Trip-like perturbations were imposed using a modified treadmill setup with a protecting harness. Vibratory stimulation was imposed bilaterally on ankle and hip muscles to expose participants to three condition of no-vibration, 40Hz vibration, and 80Hz vibration. Kinematics of the trunk and lower-extremities were measured using wearable sensors to characterize balance recovery performance. Outcomes were response time, recovery step length, trunk angle during toe-off and heel-strike of recovery stepping, and required time for full recovery.
FINDINGS
Ankle vibratory stimulation elicited main effects on reaction time and recovery step length ( < 0.002); reaction time and recovery step length increased by 23.0% and 21.2%, respectively, on average across the conditions. Hip vibratory stimulation elicited significant increase in the full recovery time ( = 0.019), with 55.3% increase on average across the conditions.
INTERPRETATION
Current findings provided evidence that vibratory stimulation can affect the balance recovery performance, causing a delayed recovery initiation and an impaired balance refinement after the recovery stepping when applied to ankle and hip muscles, respectively.
PubMed: 38384543
DOI: 10.1016/j.heliyon.2024.e25979 -
Journal of Medical Case Reports Feb 2024Sex cord gonadal stromal tumors compose less than 10% of all testicular neoplasms and consist of a variety of histological subtypes. In 2016, the World Health... (Review)
Review
BACKGROUND
Sex cord gonadal stromal tumors compose less than 10% of all testicular neoplasms and consist of a variety of histological subtypes. In 2016, the World Health Organization introduced a novel subtype, the myoid gonadal stromal tumor, that consists of spindle-shaped cells with immunohistologic features of muscle cells. Only few cases have been reported to date. Due to its rarity and owing to its only recent introduction, the current knowledge about myoid gonadal stromal tumor is limited, and particularly, appropriate clinical management is still ill-defined.
CASE PRESENTATION
A 47-year-old man of Caucasian descent presented with nonspecific scrotal discomfort. A roundish and well demarcated hypoechoic mass of 8.5 mm in diameter was detected in the cranial region of the left testis. Serum tumor marker levels were within normal ranges. Testis-sparing surgery revealed a 9-mm whitish, hard mass with sharp surgical margin. Histologically, the neoplasm consisted of microfibrillar tissue with spindle-shaped cells harboring elongated nuclei. Immunohistochemical work-up disclosed expression of desmin, small muscle actin, and S100 protein giving evidence for the myogenic nature of the neoplastic cells. There was no indication of malignancy, neither histologically nor clinically. Follow-up of 1 year was uneventful.
CONCLUSION
A literature survey revealed 22 previous cases of myoid gonadal stromal tumor. The median age was 37 years, the median size of the neoplasm was 20 mm, and there was no side-preponderance. Myoid gonadal stromal tumor is not much different from other subtypes of gonadal stromal tumors nor from testicular gem cell tumors regarding age and laterality; however, tumor size is smaller in myoid gonadal stromal tumors than in germ cell tumors. Although rarely performed so far, testis-sparing surgery probably constitutes an appropriate treatment of this neoplasm. Myoid gonadal stromal tumor represents an emerging novel entity of benign testicular new growths that caregivers of patients with testicular tumors should be aware of.
Topics: Male; Humans; Adult; Middle Aged; Sex Cord-Gonadal Stromal Tumors; Testicular Neoplasms; S100 Proteins; Neoplasms, Germ Cell and Embryonal
PubMed: 38383445
DOI: 10.1186/s13256-024-04393-7 -
Journal of Cancer Research and... Oct 2023We report a rare case of spindle cell carcinoma, a histological subtype of metaplastic breast carcinoma, in a 40-year-old male who presented with an ulcero-proliferative...
We report a rare case of spindle cell carcinoma, a histological subtype of metaplastic breast carcinoma, in a 40-year-old male who presented with an ulcero-proliferative lump in the right breast. Fine-needle aspiration cytology of the lesion showed poorly cohesive clusters of pleomorphic spindle-shaped cells, suggestive of malignant spindle cell tumor. Right mastectomy along with ipsilateral lymph node dissection was performed. Microscopic evaluation revealed a neoplasm comprising interlacing fascicles of oval to spindled pleomorphic cells with brisk mitosis and areas of necrosis. There was no nodal metastasis. Immunohistochemistry revealed a triple-negative phenotype along with diffuse positivity for CK5/6, vimentin, and smooth muscle actin. p63, beta-catenin, and CD34 were negative. The patient subsequently received adjuvant chemotherapy with 5-fluorouracil, adriamycin, and cyclophosphamide regimen and was disease-free at 1-year follow-up.
Topics: Humans; Male; Adult; Breast Neoplasms; Mastectomy; Carcinoma; Antigens, CD34; Biopsy, Fine-Needle
PubMed: 38376321
DOI: 10.4103/jcrt.jcrt_2201_21