Variety Of Histologic Features Research Articles

A rare location of the rare tumour-chondromyxoid fibroma of calcaneum

Chondromyxoid fibroma (CMF) primary location is the long tubular bones of the lower extremity followed by foot and knee. This benign cartilaginous tumor of bone is the rarest reported neoplasm of cartilaginous origin. This mass can mimic other benign and malignant bone tumors owing to its variable histologic features. We report a case of CMF of the calcaneum with varying presentations. Pathologic examination is difficult but can be used to differentiate this lesion from more serious conditions. A quick and accurate diagnosis of CMF can prevent unnecessary treatment that could be harmful to the patient.

A Case of Pleomorphic Adenoma of the Submandibular Gland with Massive Necrosis

Pleomorphic adenoma is the most common benign tumor of the salivary glands, accounting for about 60% of all salivary gland tumors. Patients with pleomorphic adenoma usually present with a painless mass of the salivary glands, and the condition is rarely associated with a painful mass.Pleomorphic adenoma presents with a variety of histological features within the tumor, with myxoma-like tissue and cartilage components admixed with epithelial cell proliferation, which may be accompanied by cystic degeneration. Necrosis of these salivary gland tumors following fine-needle aspiration biopsy has been documented. However, spontaneous necrosis of pleomorphic adenomas is extremely rare. We report a case of a 32-year-old woman who presented with a rapidly growing painful swelling under the mandible. Ultrasonography revealed a tumor in the right submandibular gland. Fine-needle biopsy of the right submandibular gland led to suspicion of a malignant tumor. We performed surgical resection of the submandibular gland. The histopathological diagnosis was pleomorphic adenoma with extensive internal necrosis.

Extensive glandular and neuroendocrine differentiation of a malignant peripheral nerve sheath tumor in a neurofibromatosis-1 patient

The histologic diagnosis of a malignant peripheral nerve sheath tumor (MPNST) is complex with no defining biomarkers or generally accepted diagnostic criteria, but based on whether it is identified arising from a peripheral nerve, arising from a benign nerve sheath tumor, in the setting of neurofibroma or when its constellation of features suggest a Schwann-cell differentiation [1- 3]. Further complicating the histologic diagnosis is the small subset of these tumors with divergent differentiation demonstrating various heterologous elements [4]. Divergent differentiation presenting in a glandular form in MPNST is particularly rare, though has been described, usually in context of Neurofibromatosis I (NF1) patients, as discrete localized areas occasionally associated with neuroendocrine features [3,5,6]. Being aware of the possible extent of variable histologic features is critical for diagnosis, particularly if only a needle core biopsy is provided. We present a case of MPNST arising in a 20-year-old woman with NF1 found to have an unusual extensive glandular and neuroendocrine divergent differentiation comprising more the 75% of the tumor, arising from a plexiform neurofibroma. The patient had a prior MPNST resected without evidence of divergent differentiation, and then a subsequent metastasis to the base of the skull with similar glandular histology following our presenting case. To our knowledge, such extensive glandular and neuroendocrine differentiation has not been previously described in these tumors.

Mutations in proteins involved in E-C coupling and SOCE and congenital myopathies.

In skeletal muscle, Ca2+ necessary for muscle contraction is stored and released from the sarcoplasmic reticulum (SR), a specialized form of endoplasmic reticulum through the mechanism known as excitation-contraction (E-C) coupling. Following activation of skeletal muscle contraction by the E-C coupling mechanism, replenishment of intracellular stores requires reuptake of cytosolic Ca2+ into the SR by the activity of SR Ca2+-ATPases, but also Ca2+ entry from the extracellular space, through a mechanism called store-operated calcium entry (SOCE). The fine orchestration of these processes requires several proteins, including Ca2+ channels, Ca2+ sensors, and Ca2+ buffers, as well as the active involvement of mitochondria. Mutations in genes coding for proteins participating in E-C coupling and SOCE are causative of several myopathies characterized by a wide spectrum of clinical phenotypes, a variety of histological features, and alterations in intracellular Ca2+ balance. This review summarizes current knowledge on these myopathies and discusses available knowledge on the pathogenic mechanisms of disease.

Sclerosing odontogenic carcinoma: a rare and challenging biopsy diagnosis

<h3>Introduction</h3> Sclerosing odontogenic carcinoma (SOC) is a primary intraosseous malignancy first described by Koutlas et al. in 2008 and recently listed as a separate entity in the 2017 World Health Organization Classification of Head and Neck Tumors. Fewer than fifteen cases of SOC have been reported in the literature to date, with many mischaracterized on initial biopsy diagnosis. This mischaracterization, particularly on biopsy, is likely attributable to the subtle and variable histologic features of SOC. We present a case of SOC and review the literature with emphasis on clinical and histologic features that should raise suspicion for this lesion on biopsy. <h3>Material and Methods</h3> The biopsy specimen was submitted in a 10% formalin fixative and subsequently embedded in paraffin. The specimen was processed into four-micrometer-thick sections and stained for routine microscopic examination. Immunohistochemical studies were performed and included antibodies against CK5/6, CK19, e-cadherin, CK7, CK20, p63, and Ki67. <h3>Results</h3> A review of the literature demonstrated only one set of authors reporting an initial biopsy diagnosis of SOC. The remainder of reported cases required a minimum of one repeat biopsy, and in several cases, diagnosis was only established following complete excision. Therapeutic approaches ranged from conservative marginal excision to radical excision with neck dissection and adjuvant chemotherapy and radiation. Regardless of therapy modality all cases demonstrated no recurrence, with one exception, likely attributable to positive margin status at resection. <h3>Conclusions</h3> Given the subtle features of SOC that may often mimic other benign and malignant processes, sufficient awareness and suspicion for this entity is necessary for diagnosis, and ultimately to guide clinical management. In the absence of an established diagnosis of SOC, multiple reported patients have undergone more radical therapy than what appears to be necessary for the management of this low-grade entity with no apparent metastatic potential.

Clinical and Histological Features of Ovarian Hypoplasia/Dysgenesis in Alpacas.

Alpacas have a high incidence of congenital reproductive tract abnormalities, including ovarian hypoplasia/dysgenesis. Diagnosis of this condition is often challenging. The present study describes the clinical, ultrasonographic, and histologic features of ovarian hypoplasia/dysgenesis syndrome in 5 female alpacas. Additionally, serum AMH levels were compared between female alpacas diagnosed with ovarian hypoplasia/dysgenesis and a group of reproductively sound females (n = 11). The syndrome was suspected based on the presence of an infantile uterus and lack of ovaries by ultrasonography and laparoscopy. All females had normal female karyotype (n = 74 XX), but one presented a minute chromosome. The ovaries from these cases showed 3 main histological classifications: hypoplasia (n = 2), dysgenesis (n = 2), and dysplasia (n = 1). Serum AMH levels in affected females were significantly lower (P < 0.05) than those of reproductively sound control females. In conclusion, Serum AMH level may be helpful in the rapid diagnosis of ovarian hypoplasia/dysgenesis syndrome in alpacas. Furthermore, this syndrome in alpacas presents a variety of histological features. Different mechanisms may be involved in the derangement of ovarian differentiation. Further studies are needed to elucidate the causes of the syndrome.

Abstract SP112: Spatial variance signatures/Intra-tumor zonation in TNBC

Abstract It is increasingly clear that triple negative breast cancer (TNBC) is a heterogeneous disease with variable clinical presentation, histological features and response to therapy. While these differences have been partially explained by inter- and intra-tumoral heterogeneity, spatial heterogeneity represented by the tumor architecture plays a critical role in clonal evolution and displays a landscape for different compartment-specific processes and cell-to-cell specific interactions. To better understand the impact of spatial heterogeneity on gene-expression-defined cell populations, we have coupled single-cell RNA sequencing with multiplex immunofluorescence (IF). Multiplex immunofluorescence using specific markers for each cell cluster, integrated with computational image analyses and neighborhood maps, has revealed spatial zonation of single cell subpopulations. Zonation of single cell populations was coupled to hypoxia and overlayed distinct metabolic tumor zones and defined areas of differential stress and cell plasticity that give rise to tumor cells with enhanced fitness and aggressivity. Citation Format: M Park, C Martínez Ramirez, Y Yang, A Blanchet-Cohen, H Kuasne, A Fortier, J Ragoussis, P Savage, A Omeroglou, S Meterissian, S Costantino, C Kleinman. Spatial variance signatures/Intra-tumor zonation in TNBC [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr SP112.

Rare case of gastric inflammatory fibroid polyp located at the fornix of the stomach and mimicking gastric cancer: a case report

BackgroundGastric inflammatory fibroid polyp (IFP) is a rare polypoid lesion of the stomach that is characterized pathologically by the presence of spindle cells, a prominent network of blood vessels, and inflammatory infiltration of eosinophils. IFP is mainly located in the gastric antrum and is usually semi-pedunculated and covered with normal mucosa. There have been several reports of large IFPs with ulceration on the surface, at the apex, but no report of the IFP with ulceration at the fornix of the stomach. We report a case of IFP with ulceration that was suggested to be gastric cancer and was resected for diagnostic treatment.Case presentationA 79-year-old woman presented to our hospital. During mass screening for cancer, stomach fluoroscopy revealed an abnormal shadow. Endoscopy showed an ulcerated tumor at the fornix of stomach; hence, gastric cancer was suggested because of the polypoid lesion with irregular ridges and ulceration. Pathological diagnosis of gastric biopsy specimens revealed an inflammation of the gastric mucosa, and specific findings for gastric cancer were not obtained. Because we could not exclude gastric malignancies such as cancer or gastrointestinal stromal tumor, we performed a partial resection of the stomach with a 2-cm margin using the laparoscopic-assisted method. Pathological examination of the resected specimen revealed that the tumor was present in the submucosal layer and consisted of collagen fiber containing inflammatory cell infiltration of mainly eosinophils. A prominent network of blood vessels was also found in the specimens. Immunohistochemical staining revealed mild positivity for CD34, and α-SMA and was negative for c-kit, DOG-1, s-100, desmin, ALK, and IgG4. The lesion was thus diagnosed as an IFP. The postoperative course was uneventful. The patient is currently asymptomatic and has shown no recurrence.ConclusionIFPs have variable locational, morphological, histological, pathological, and immunohistochemical features. We reported that the gastric IFP was located at the fornix of the stomach and was similar in morphology to gastric cancer. This case is clinically significant to avoid over-surgery.

Choroid Plexus Carcinoma with Hyaline Globules: An Uncommon Histological Finding

Background: Choroid plexus carcinoma (CPC) is a predominately pediatric CNS tumor with a variety of histologic features, with hyaline globules only reported once previously. Case report: A two-year-old male child presented with headaches, vomiting, and lower limb weakness. Radiological examination revealed a right temporoparietal intra-axial tumor. On histology, it showed features of CPC containing multiple eosinophilic intracytoplasmic and extracellular hyaline globular structures, which were PAS-positive, diastase resistant, and immunoreactive for alpha-fetoprotein (AFP). Conclusion: CPC can occasionally show AFP immune-positive hyaline globules.

Intestinal hypomotility in systemic sclerosis: a histological study into the sequence of events

ObjectivesThe pathogenesis of intestinal involvement in systemic sclerosis (SSc) is thought to be a sequential process (vascular, neuronal, and consecutive muscular impairment), but understanding of the underlying histological changes and how they translate to symptoms, is still lacking. Therefore, we systematically investigated histological characteristics of SSc in the intestines, compared to controls.MethodsAutopsy material from the small bowel and colon was used for histological semiquantitative evaluation of the vasculature, enteric nervous system, interstitial cells of Cajal (ICC), and muscle layers, using a combination of histochemical and immunohistochemical stainings, according to guidelines of the Gastro 2009 International Working Group.ResultsVascular changes were most frequently encountered, represented by intima fibrosis in both arteries and small vessels, and represented by venous dilatation. Second, generalized fibrosis of the circular muscle layer was significantly more found in SSc patients than in controls. Third, reduction of submucosal nerve fibers and myenteric neurons was shown in the colon of four SSc patients, which may explain severe symptoms of intestinal dysmotility. The density of myenteric ICC network was decreased in the small bowel of SSc patients.ConclusionsThe postulated sequential processes of intestinal involvement in SSc could not be supported by our histological evaluation. The interpatient diversity suggests that parallel processes occur, explaining the variety of histological features and clinical symptoms.Key Points• Histological analysis showed vascular changes, fibrosis in the muscularis propria, and reduction of the ENS and ICC network in the intestines of SSc patients.• Pathophysiological mechanisms leading to intestinal dysmotility in SSc may be parallel rather than sequential.• The interpatient diversity suggests parallel pathophysiological processes, explaining the variety of histological features and clinical symptoms.

Cryobiopsy in the diagnosis of bronchiolitis: a retrospective analysis of twenty-three consecutive patients

Bronchiolitis manifests as a variety of histological features that explain the complex clinical profiles and imaging aspects. In the period between January 2011 and June 2015, patients with a cryobiopsy diagnosis of bronchiolitis were retrospectively retrieved from the database of our institution. Clinical profiles, imaging features and histologic diagnoses were analysed to identify the role of cryobiopsy in the diagnostic process. Twenty-three patients with a multidisciplinary diagnosis of small airway disease were retrieved (14 females, 9 males; age range 31–74 years old; mean age 54.2 years old). The final MDT diagnoses were post-infectious bronchiolitis (n = 5), constrictive bronchiolitis (n = 3), DIPNECH (n = 1), idiopathic follicular bronchiolitis (n = 3), Sjogren’s disease (n = 1), GLILD (n = 1), smoking-related interstitial lung disease (n = 6), sarcoid with granulomatous bronchiolar disorder (n = 1), and subacute hypersensitivity pneumonitis (n = 2). Complications reported after the cryobiopsy procedure consisted of two cases of pneumothorax soon after the biopsy (8.7%), which were successfully managed with the insertion of a chest tube. Transbronchial cryobiopsy represents a robust and mini-invasive method in the characterization of small airway diseases, allowing a low percentage of complications and good diagnostic confidence.

Dedifferentiated Liposarcoma With Meningothelial-Like Whorls: Five Additional Cases and Review of the Literature.

Background. Diagnosis of dedifferentiated liposarcoma (DDL) can sometimes be challenging due to a wide variety of histological features. "Meningothelial-like" whorl is an uncommon histological feature of DDL, which is also observed in neural tumors and follicular dendritic cell sarcoma. This feature is frequently associated with metaplastic bone formation. We conducted this study to describe the clinicopathological features of DDL with meningothelial-like whorls that would aid in establishing accurate diagnosis. Material and Methods. Microscopic glass slides of 5 cases of DDL with meningothelial-like whorls, diagnosed between January 2010 and December 2019, were reviewed. Results. Paratesticular region was the most common site. Whorls occupied 10% to 75% of tumor area and ranged in size from <0.1 cm to >2 cm. In 1 case, these whorls coalesced to form large areas of dedifferentiation. The cells forming whorls were spindle to epithelioid shaped and lacked significant nuclear pleomorphism and increased mitoses. Metaplastic bone formation was observed in 4 cases and cartilage formation in 3 cases. p16 and α-smooth muscle actin (α-SMA) immunohistochemical stains were positive in 2 cases, when performed. MDM2 gene amplification was observed in all cases by fluorescence in situ hybridization technique. These tumors showed aggressive behavior, similar to that of DDL without meningothelial-like whorls. Two patients died, 1 developed recurrence, 1 presented as recurrent tumor, and 1 developed metastasis. Conclusion. Meningothelial-like whorls in DDL most likely represent an early stage of dedifferentiation. Presence of well-differentiated liposarcoma areas, metaplastic bone formation, positive expressions for p16 and α-SMA immunohistochemical stains, and MDM2 gene amplification are useful diagnostic clues. These tumors have the potential to behave aggressively.

Analysis of chromosome 12p over-representation and clinicopathological features in mediastinal teratomas

Teratomas show diverse biologic behaviour and prognosis as well as variable histological features. Importantly, post-pubertal testicular teratomas composed of mature components have a potential for malignant behaviour, in contrast to ovarian dermoid cysts and pre-pubertal testicular teratomas which are considered almost always benign. On the other hand, the biological behaviour and histogenesis of extragonadal teratomas are still not fully elucidated. In this study of mediastinal mature teratoma (MT), we investigated clinicopathological features and chromosome 12 short arm (12p) status which constitutes a major genetic aberration in the germ cell tumours (GCT) and is indicative of malignant potential. A total of 123 cases of primary mediastinal MT were included, and clinical data were retrieved regarding demographic information, adjuvant treatment, post-operative clinical course, and level of serum tumour markers. Histopathological features were evaluated in 123 cases and 12p status was studied by FISH in 25 cases. Female predilection was identified in the post-pubertal group (38 males vs 77 females), and paediatric teratoma cases had longer follow-up (mean 62.2 months vs 26.5 months). All patients had excellent prognosis with no tumour-associated death, regardless of age and sex. None of the MT cases had cytological atypia and all 21 cases finally evaluated by fluorescence in situ hybridisation were negative for 12p over-representation. Our results support the benign nature of mediastinal MT and suggest the possibility that it may share a common histogenesis with pre-pubertal type GCTs.

Review of Autoimmune Hepatitis: Diagnosis and Treatment

Background: Autoimmune hepatitis (AIH) is a hepatocyte injury characterized by a dis-regulated immune system, inflammation of the liver with interface hepatitis, serum antibodies and elevated gamma-globulins. Currently, it exists 2 mainly types on autoimmune hepatitis, based on the presentation of their autoantibodies: type 1 and 2. Type 1 is the one of interest in this review. Autoimmune hepatitis type 1 is an indolent inflammatory disease mediated by abnormal autoimmune reaction, commonly seeing in women (4:1), with no preference of age, however typically present in 4th and 6th decade’s individuals, and a good response to immunosuppressive therapy. Autoimmune hepatitis is known to present not specific symptoms which can go from inexistent to fulminant or exacerbate presentation. The incidence of autoimmune hepatitis in western country is 1/5000 - 1/10,000. Although the detection rate of AIH increasing, especially in China, autoimmune hepatitis diagnosis and treatment remain challenging. Most AIH case do not present pathognomonic biomarkers, however the diagnostic has to considerate other features, which had been codified into validated diagnosis scoring systems. Regarding the treatment, based on prior literature autoimmune hepatitis is mostly sensitive to prednisone or azathioprine, however the use of other immunosuppressive agent or event their combination had offer distinct advantages. Autoimmune hepatitis presents a great life threatening disorder especially because of the delay in the early stage on the disease, the not specific presentations, and the large overlap syndrome associate with it. A deep knowledge in its identification, specific diagnostic criteria, and its therapeutic strategy is much needed. Conclusion: Autoimmune hepatitis is a systemic disease that is difficult to recognize because of its variable clinical presentation and histological features that are not strictly specific. Several new autoantibodies as well as recently simplified diagnostic criteria may allow the primary care physician to progress in the diagnostic process. This is all the more important as undiagnosed and therefore untreated autoimmune hepatitis has a poor prognosis and immunosuppressive treatment leads to remission in a large majority of cases.

The developmental programme for genesis of the entire kidney is recapitulated in Wilms tumour.

Wilms tumour (WT) is an embryonal tumour that recapitulates kidney development. The normal kidney is formed from two distinct embryological origins: the metanephric mesenchyme (MM) and the ureteric bud (UB). It is generally accepted that WT arises from precursor cells in the MM; however whether UB-equivalent structures participate in tumorigenesis is uncertain. To address the question of the involvement of UB, we assessed 55 Wilms tumours for the molecular features of MM and UB using gene expression profiling, immunohistochemsitry and immunofluorescence. Expression profiling primarily based on the Genitourinary Molecular Anatomy Project data identified molecular signatures of the UB and collecting duct as well as those of the proximal and distal tubules in the triphasic histology group. We performed immunolabeling for fetal kidneys and WTs. We focused on a central epithelial blastema pattern which is the characteristic of triphasic histology characterized by UB-like epithelial structures surrounded by MM and MM-derived epithelial structures, evoking the induction/aggregation phase of the developing kidney. The UB-like epithelial structures and surrounding MM and epithelial structures resembling early glomerular epithelium, proximal and distal tubules showed similar expression patterns to those of the developing kidney. These observations indicate WTs can arise from a precursor cell capable of generating the entire kidney, such as the cells of the intermediate mesoderm from which both the MM and UB are derived. Moreover, this provides an explanation for the variable histological features of mesenchymal to epithelial differentiation seen in WT.

A mouse mastitis model to study the effects of the intramammary infusion of a food-grade Lactococcus lactis strain.

Lactococcus lactis is one of the most important microorganisms in the dairy industry and has “generally recognized as safe” (GRAS) status. L. lactis belongs to the group of lactic acid bacteria (LAB) and is encountered in a wide range of environments. Recently, the use of the intramammary infusion of a live culture of LAB has been investigated as a new antibiotic alternative for treating mastitis in dairy ruminants. Controversial results are described in literature regarding its efficacy and safety. In this study we conducted in-depth investigation of the mammary gland immune response induced by intramammary inoculum of a live culture of L. lactis LMG 7930 using the mouse mastitis model. Overnight cultures either of L. lactis (≈ 107 CFU) or of the mastitis pathogens Staphylococcus chromogenes (≈ 105 CFU) or S. aureus (≈ 102 CFU/ml) were injected into the mouse inguinal glands. A double injection, consisting of S. chromogenes first and then L. lactis, was also investigated. Bacterial recovery from the gland and inflammatory cell infiltration were assessed. L. lactis-treated and control glands were analysed for proinflammatory cytokine production. Microbiological results showed that L. lactis was able to survive in the mammary gland 24 h post infection, as were the mastitis pathogens S. chromogenes and S. aureus. L. lactis reduced S. chromogenes survival in the glands and increased its own survival ability by coexisting with the pathogen. Histology showed that L. lactis-treated glands presented variable histological features, ranging from undamaged tissue with no inflammatory cell infiltrate to severe PMN infiltrate with focal areas of tissue damage. S. aureus-treated glands showed the most severe histological grade of inflammation despite the fact that the inoculum size was the smallest. In contrast, most S. chromogenes-treated glands showed normal structures with no infiltration or lesions. Significant increases in IL-1β and TNF-α levels were also found in L. lactis-inoculated glands. The above findings seem to suggest that food-grade L. lactis at a high-inoculum dose such as an overnight culture may elicit a suppurative inflammatory response in the mammary gland, thus becoming a potential mastitis-causing pathogen. Because of the unpredictable potential of L. lactis in acting as a potential mastitis pathogen, this organism cannot be considered a safe treatment for bovine mastitis.

Leiomyosarcoma of the Skin and Subcutaneous Tissue in a Nellore Cow

Background: Leyomiosarcomas are uncommon malignant smooth muscle tumors of hollow organs. Bovine leyomiosarcomas have been described in several sites, but smooth muscle tumors that arise from the skin are rare in domestic animals. These neoplasms may show variable histologic features depending on their grade of differentiation; therefore, diagnostic tools as special stain, electron microscopy and immunohistochemistry are essential for the definitive diagnosis. Due to the lack of reports of skin leyomiosarcomas in cattle, we described the occurrence of a leyomiosarcoma in the skin and subcutaneous tissue of a Nellore cow.Case: A 10-year-old Zebu Nellore cow was admitted at the Veterinary Diagnosis Center (CEDIVET) of Pará Federal University (UFPA), Brazil, to investigate a tumor on the hip. At clinical examination the cow showed a decreased appetite and weight loss. Due to the bad prognosis the veterinarian recommended euthanasia. Representative tissue samples were submitted for histopathological and immunohistochemistry evaluation at the Department of Pathology of the Federal Rural University of Rio de Janeiro (UFRRJ). The slides were stained by Hematoxylin and Eosin (HE), Masson’s trichrome and Van Gieson stains and submitted for immunohistochemistry with primary antibodies vimentin, troponin C, smooth muscle alpha actin and desmin. Grossly, the tumor appeared as a multilobular, ulcerated and firm 30 cm diameter mass with black and hemorrhagic areas on the surface. The mass was scattered throughout the subcutaneous tissue and infiltrated the adjacent muscle. On light microscopy, the neoplasm consisted of a non-encapsulated proliferation into the derma, composed of highly pleomorphic spindle to round cells arranged in broad interlacing fascicles and small islands. Metastatic lesions were found in the lungs and local lymph nodes. Masson’s trichrome stain revealed collagen production and Van Gieson stains was inconsistent. Immunohistochemically, the neoplastic cells expressed vimentin diffusely and smooth Alfa actin in 10% of the cells. Desmin and troponin C failed to express immunoreactivity.Discussion: The histological, histochemical and immunohistochemical features of the neoplasm were consistent with a leiyomiosarcoma of the skin and subcutaneous tissue. Leiomyosarcomas are uncommon in farm animals and most of them arise from the female genital tract, especially in the vagina and within the uterus. The majority of smooth muscle tumors of the skin are benign; however, we described here a neoplasm that displayed clear signs of malignancy. Due to the high grade of differentiation, Van-Gieson stain failed to determine the origin of the neoplasm. Many sarcomas have resembling histologic features and busually display interlacing bundles of spindle shaped cells, similar to the pattern described in the present tumor. Therefore, immunohistochemistry stain with vimetin and smooth alpha actin was essential for the definitive diagnosis. We identified metastatic lesions in the local lymph nodes and lungs. This tumor tends to develop slowly and metastasize late. These findings underline the importance of diagnostic tools, such as immunohistochemistry and special stains to guide the pathologist and to establish the diagnosis of bovine smooth muscle tumors. Consequently, an association of histochemical and immunohistochemical procedures is indispensable to guide the pathologist for the establishment of the diagnosis of bovine smooth muscle tumors.

Grading Renal Cell Carcinoma: The International Society of Urological Pathology Grading System

HISTOLOGICAL grade of renal cell carcinoma has long been linked to outcome for patients with renal cell carcinoma and, indeed, is one of the most powerful prognostic indicators for this malignancy. Over the years a variety of histological features have been used in the assignment of renal cell carcinoma histological grade, including tumor architecture, mitotic rate, cellular morphology, tumor necrosis, nuclear pleomorphism, and nuclear and nucleolar enlargement. The Fuhrman grading system, used by pathologists around the world, is based on nuclear size, nuclear shape, nucleolar size and nuclear pleomorphism. In practice, however, many pathologists rely on assessment of nucleolar prominence alone and it has been proposed that the grading of clear cell renal cell carcinoma should be based on nucleolar prominence. Recently, the International Society of Urological Pathology (ISUP) held a consensus conference on the classification, prognostic factors, staging, and immunohistochemical and molecular assessment

Histologic Features in Colon Biopsies Can Discriminate Mycophenolate From GVHD-induced Colitis

Mycophenolate mofetil (MMF) is a T-cell inhibitor frequently used in the treatment of acute allograft rejection. MMF may cause colitis that clinically and histologically resembles graft-versus-host disease (GVHD). The aim of this study was to evaluate a wide range of histologic features that may help differentiate MMF from GVHD-induced colitis and to validate significant features on a cohort of bone marrow transplant patients who were also taking MMF as part of their immunosuppressive regimen and developed a diarrheal illness due to colitis. Routinely processed colonic biopsies from 17 patients with MMF colitis and 40 patients with GVHD-induced colitis were evaluated for the overall grade of colitis (grades 1 to 4) and histologically for a wide range of inflammatory, epithelial, and architectural changes in a blinded manner. Statistically significant features were then tested in a cohort of 20 bone marrow transplant patients who also received MMF, and later developed a diarrheal illness. Both univariate and multivariate analyses (including receiver operating characteristic analysis) were performed. Morphologic features shown to be independently associated with MMF include the presence and quantity of lamina propria eosinophils and endocrine cell aggregates and the presence and quantity of apoptotic microabscesses, hypereosinophilic (degenerated) crypts, and crypt distortion. Eosinophils were present in all MMF patients, but apoptotic microabscesses were present in none and endocrine cell aggregates in only 1 case. When a grade-by-grade comparison was made between MMF and GVHD, grade 1 or 2 MMF also showed an increased prevalence rate and quantity of lamina propria neutrophils in comparison with grade 1 or 2 GVHD. By receiver operating characteristic analysis, a combination of lamina propria eosinophils >15 per 10 HPF, combined with a lack of endocrine cell aggregates and apoptotic microabscesses, revealed sensitivity, specificity, and positive and negative predictive values of 76%, 93%, 81%, and 90%, respectively, for identification of MMF colitis. On the basis of these data, we conclude that a variety of histologic features, in particular, eosinophils >15 per 10 HPF, lack of endocrine cell aggregates in the lamina propria, and lack of apoptotic microabscesses, can be used by pathologists to help separate MMF from GVHD-induced colitis in routine clinical practice.

Chondromyxoid Fibroma of the Calcaneus: Two Case Reports and Literature Review

Chondromyxoid fibroma occurs primarily in the long tubular bones of the lower extremity, with the foot representing the second most frequent location after the knee. This benign cartilaginous tumor of bone is currently the rarest reported neoplasm of cartilaginous origin. This mass can mimic other benign and malignant bone tumors owing to its variable histologic features. We report 2 cases of chondromyxoid fibroma of the calcaneus with varying presentations. Initially, advanced imaging studies pointed to a diagnosis of a unicameral bone cyst. Pathologic examination is difficult but can be used to differentiate this lesion from more serious conditions. A quick and accurate diagnosis of chondromyxoid fibroma can prevent unnecessary treatment that could be harmful to the patient.