Revolutionizing Digital Pathology With the Power of Generative Artificial Intelligence and Foundation Models

Digital pathology has transformed the traditional pathology practice of analyzing tissue under a microscope into a computer vision workflow. Whole-slide imaging allows pathologists to view and analyze microscopic images on a computer monitor, enabling computational pathology. By leveraging artificial intelligence (AI) and machine learning (ML), computational pathology has emerged as a promising field in recent years. Recently, task-specific AI/ML (eg, convolutional neural networks) has risen to the forefront, achieving above-human performance in many image-processing and computer vision tasks. The performance of task-specific AI/ML models depends on the availability of many annotated training datasets, which presents a rate-limiting factor for AI/ML development in pathology. Task-specific AI/ML models cannot benefit from multimodal data and lack generalization, eg, the AI models often struggle to generalize to new datasets or unseen variations in image acquisition, staining techniques, or tissue types. The 2020s are witnessing the rise of foundation models and generative AI. A foundation model is a large AI model trained using sizable data, which is later adapted (or fine-tuned) to perform different tasks using a modest amount of task-specific annotated data. These AI models provide in-context learning, can self-correct mistakes, and promptly adjust to user feedback. In this review, we provide a brief overview of recent advances in computational pathology enabled by task-specific AI, their challenges and limitations, and then introduce various foundation models. We propose to create a pathology-specific generative AI based on multimodal foundation models and present its potentially transformative role in digital pathology. We describe different use cases, delineating how it could serve as an expert companion of pathologists and help them efficiently and objectively perform routine laboratory tasks, including quantifying image analysis, generating pathology reports, diagnosis, and prognosis. We also outline the potential role that foundation models and generative AI can play in standardizing the pathology laboratory workflow, education, and training.

Eigenvalue based spectral classification

This paper describes a new method of classification based on spectral analysis. The motivations behind developing the new model were the failures of the classical spectral cluster analysis based on combinatorial and normalized Laplacian for a set of real-world datasets of textual documents. Reasons of the failures are analysed. While the known methods are all based on usage of eigenvectors of graph Laplacians, a new classification method based on eigenvalues of graph Laplacians is proposed and studied.

[Unilateral optic disc oedema as a first sign of ocular toxoplasmosis – case report]

Diagnostic procedure for unilateral optic disc oedema needs detailed medical history, careful physical examination and multiple additional tests. We present a very rare case of atypical unilateral anterior optic neuropathy as a sign of ocular toxoplasmosis in a young female. All diagnostic and therapeutic challenges have been discussed.

Clinical manifestation of self-limiting acute retinal necrosis

Background

The purpose of this paper was to present a case series of self-limiting, peripheral acute retinal necrosis and to demonstrate efficacy of treatment with valacyclovir in patients resistant to acyclovir. The diagnosis was made on ophthalmoscopic examination and positive serum tests for herpes viruses.

Material/Methods

Ten patients (6F and 4M) aged 19–55 years were diagnosed and treated for self-limiting acute retinal necrosis (ARN). The following endpoints were reported: visual outcomes, clinical features, disease progression, treatment, and complications. Patients received only symptomatic treatment because they did not consent to vitreous puncture.

Results

Peripheral, mild retinitis was diagnosed in all eyes at baseline. Initially, all patients were treated with systemic acyclovir (800 mg, 5 times a day), prednisone (typically 40–60 mg/day), and aspirin in an outpatient setting. In 6 patients, treatment was discontinued at 6 months due to complete resolution of the inflammatory process. Four patients with immune deficiency showed signs and symptoms of chronic inflammation. Two patients did not respond to acyclovir (2 non-responders); however, those patients were successfully treated with valacyclovir. Complete resolution of inflammatory lesions was observed in 8 patients. In 2 patients, the disease progressed despite treatment – 1 female patient after kidney transplant who stopped the prescribed medications, and 1 male patient with SLE and antiphospholipid syndrome who experienced breakthrough symptoms on-treatment. He died due to cerebral venous sinus thrombosis. Neurological complications (encephalitis and meningitis) were observed in 2 female patients. Prophylactic laser photocoagulation was performed in 1 subject.

Conclusions

A series of cases of self-limiting acute retinal necrosis (ARN) is presented. This clinical form of ARN can resemble toxoplasmic retinitis in some cases. Oral antiviral medications provide an effective alternative to intravenous formulations in patients with self-limiting ARN. Retinitis is associated with the risk of encephalitis.

Spotted fever rickettsiosis caused by Rickettsia raoultii--case report

We report the case of rickettsial eschar-associated spotted fever, most probable due to Rickettsia raoultii, an emerging pathogen, which was previously described in patients with tick-borne lymphadenopathy (TIBOLA), also called Dermacentor-borne necrosis erythema and lymphadenopathy (DEBONEL). The pathogenicity of R. raoultii is not well established. The survey of ticks from Poland (Ixodes ricinus and Dermacentor reticulatus) revealed that R. raoultii occur in all regions of Poland and predominate over other rickettsiae of spotted fever group--R. slovaca and R. helvetica. A 17-year-old otherwise healthy girl was admitted to Department of Zoonotic and Tropical Diseases because of fever, eschar and rash. Multiple disseminated small lesions were present on the skin of her head, trunk and limbs, also palms and soles, and mucosa of her lips. The majority of them had necrotic center slightly elevated with redness around, single ones had vesicular appearance. The lymph nodes on the right side of her neck were enlarged. Laboratory investigations revealed: leukopenia (with 22% of bands in differential), thromocytopenia, slightly elevated C-Reactive Protein, as well as procalcytonin. The quick improvement was observed with a treatment with ceftriaxone and doxycycline. Two weeks after the onset of disease, IgG serum antibodies titer of 128 reacting with R. rickettsii antigen only was detected. IFA tests with six SFG rickettsial species demonstrated the strongest reaction with R. raoultii group antigens in a titer of 64. The case we report, resembling boutonneuse fever, with leukopenia, thrombocytopenia and septic parameters indicates possible higher virulence of R. raoultii than it was previously observed.

Finite element analysis of artificial disc with an elastomeric core in the lumbar spine

This paper presents the application of finite element method in an artificial disc modelling. The prosthesis consisted of two metal plates and a flexible elastomeric core made of the nanocomposite polyurethane. Two types of connections between the plates and the core were compared: the device with an integral inlay and the device with a separate inlay coming into contact with the plates. The artificial disc with a separate inlay imitated better the human intervertebral disc. The main target of this paper was to evaluate the characteristics of force-displacement and moment-angle for the new design of the prosthesis with a separate inlay under compression, sagittal bending, shear and axial rotation. For some analyzed cases except the axial rotation and shear, where the prosthesis was too flexible, the results were roughly similar to those observed in the human spinal segment. The material effort in the prosthesis under compressive load was comparable in both types of connections between the plates and the core.

Expandable Non-invasive Prostheses - an Alternative to Pediatric Patients with Bone Sarcoma

In the paper the problem of joint arthroplasty in children who have not reached their maturity is raised. The arthroplasty concerns replacement of a joint that does not function due to bone sarcoma that a child suffers from. Osteosarcoma and Ewing's sarcoma are the most common types of pediatric bone cancer and they afflict mainly long bones, i.e. femur and tibia. In such cases there are only two options: to amputate the affected limb or to replace the diseased bone. It goes without saying that the latter solution is most acceptable by patient and surgeon. However, a special prosthesis has to be applied as the limbs still grow. To avoid leg length discrepancy between the healthy limb and the affected one expandable prostheses are inserted. Specific designs of such prostheses allow one to lengthen the operated limb and preserve the same length of the two legs. In the paper an overview of expandable prostheses is presented. Also our own designs of expandable orthopaedic devices are shown. The devices are characterised by the fact that their length can be intelligently extended by means of a special electro-magnetic set.

Onychomycosis: an analysis of 50 cases and a comparison of diagnostic techniques

Onychomycosis is an extremely common condition that is increasing in prevalence. Although often innocuous, it may be complicated by discomfort and secondary bacterial infections. Recently introduced oral medications may be highly effective in the eradication of this condition; however, they may carry with them significant expense and potentially serious side effects. Prior to the initiation of antifungal oral therapy, definitive diagnosis is mandatory. This study compares the sensitivity of potassium hydroxide (KOH) preparations, surgical pathology diagnostic testing (SPDT), and culture techniques for the detection of onychomycosis in 50 cases of clinically suspected onychomycosis. Analysis showed that SPDT was significantly more sensitive when compared to KOH and culture. The results suggest that SPDT may be the true gold standard for the diagnosis of onychomycosis.

Primary soft-tissue neoplasms of the foot: the clinicopathologic features of 401 cases

Neoplasms of the soft tissue range from benign, indolent tumors to some of the most aggressive malignancies known to man. Despite exhaustive studies detailing their occurrence elsewhere within the body, there has been relatively little detailing such neoplasms arising within the soft tissues of the foot. Due to the relative infrequency with which malignant soft-tissue tumors occur in the foot, large series pertaining to this location have been difficult to assemble. To better elucidate the relative frequency of various benign and malignant soft-tissue tumors of the foot, the clinicopathologic features of 401 such neoplasms are described. All cases were retrieved from the files of a major medical center which specializes in the treatment of cancer. Of the 401 cases identified, 149 were benign, while 252 cases were of a malignant nature. The clinicopathologic features are summarized and descriptive statistics are applied. Special focus is given to the discussion of the malignant and rare tumors within this series. Recent concepts regarding diagnosis, prognosis, and therapy are similarly discussed.

Aggressive epithelioid hemangioendothelioma of the lower extremity: a case report and review of the literature

A case of epithelioid hemangioendothelioma (EHE) of the left lower extremity in a 50-year-old male is discussed. The neoplasm presented as a tan-purple, painful mass involving the fourth digit of the left foot. Following an excisional biopsy and partial amputation of the fourth digit, the lesion recurred with a multifocal distribution. A physical exam following the recurrence demonstrated multiple palpable lymph nodes in the left inguinal region. A complete amputation of the fourth digit was performed in conjunction with local excisions of the remaining lesions. Additionally, an inguinal lymphadenectomy was performed for staging purposes. Histologically, the tumor was predominantly composed of epithelioid endothelial cells forming nests, cords, and sheets and occasionally forming irregular, primitive vascular structures. Less commonly, nests of tumor cells assumed a spindled morphology. Patches of necrosis and hemorrhage were apparent throughout the neoplasm. There was minimal atypia and mitoses were not identified. Immunohistochemical stains for CD34, CD31, and Ulex europaeus antigens were positive in tumor cells. This case illustrates the potential aggressive behavior of this rare neoplasm and argues against the designation "tumor of low-grade malignancy" with which it is commonly attributed.

Histologic findings in postcryosurgical prostatic biopsies

The increasing use of cryosurgical ablation of the prostate for prostatic carcinoma necessitates that surgical pathologists be aware of the cryosurgically induced histologic changes in the prostate. Twenty-one patients at our institution underwent prostatic cryosurgery, and 17 subsequently had follow-up biopsies. The Gleason combined scores ascribed to the original tumors were 4 (two patients), 5 (six patients), 6 (seven patients), 7 (one patient), and 8 (one patient). Histologic examination revealed residual carcinoma (four patients, with Gleason combined scores of 4, 5, 6, and 8), necrosis (all 17 patients), hyalinization (nine patients), fibrosis (nine patients), granulomatous inflammation (three patients), foci of calcification (eight patients), squamous metaplasia (four patients), transitional metaplasia (two patients), hemosiderin deposition (six patients), edema (two patients), bacterial colonization (one patient), and hemorrhage (one patient). The grade of residual carcinoma in all four patients was identical with the grade assigned before the cryosurgical ablation. The stroma surrounding the residual tumor did not display any postcryosurgical histologic changes, and we postulate that these areas were not adequately frozen. In conclusion, prostatic cryotherapy induces a variety of histologic changes in normal and diseased tissue.

Quantitative image analysis of p53 protein accumulation in keratoacanthomas

Keratoacanthomas are benign skin tumors that grow rapidly but eventually regress. They occur most commonly in sun-exposed skin and are histologically remarkably similar to squamous cancers. Since mutations of the p53 tumor suppressor gene are found frequently in cutaneous squamous cell carcinomas, we hypothesized that p53 mutations might contribute to the development of keratoacanthomas. To address this question, we did p53 immunohistochemistry with a polyclonal rabbit antiserum, CM-1, that binds both mutant and wild-type p53 proteins. Although wild-type p53 protein degrades rapidly and is generally undetected by immunohistochemistry, mutant p53 protein has a longer half-life and accumulates to detectable levels. We tested 26 formalin-fixed keratoacanthomas and 4 normal skin biopsies. Positive nuclear staining was detected in 20 of 26 (77%) of the keratoacanthomas and in none of the normal skin samples. Nuclear staining occurred in the outermost layer of the neoplasms and not in the keratin-filled central cores. Since nuclear p53 protein within a cutaneous squamous cell carcinoma usually correlates with missense mutation, these data suggest that p53 mutations contribute to the development of this benign neoplasm. The histologic similarity to squamous cell carcinoma and the accumulation of p53 protein suggest progression toward malignancy, but the invariable regression of these tumors suggests an arrest at some point in multistage carcinogenesis. If this model is correct, then genetic analysis of keratoacanthomas may provide clues to the later stages of squamous carcinogenesis including local invasion and metastasis.

Studies on TGF-beta 1 gene expression in the intima of the human aorta in regions with high and low probability of developing atherosclerotic lesions

Certain regions of the human aorta are at greater risk for early and more severe atherosclerotic lesions development than others. Cornhill and coworkers (Cornhill FJ et al.: Arteriosclerosis 5:415, 1985) created maps for the probability of developing atherosclerosis defining the high-probability region (HPR) in the dorsal descending thoracic aorta and the low-probability region (LPR) in the ventral descending thoracic aorta. Our study examines the hypothesis that transforming growth factor beta -1 (TGF-beta 1), a well-known suppressor of growth and function in many human cell lines, is one of the inhibitors of human atherogenesis. The present experiment analyzes the expression of mRNA for TGF-beta 1 in both the HPR and the LPR of aortas from young (age 17 to 25 y) males of black (n = 8) and white (n = 7) race. The level of TGF-beta 1 gene expression was assessed in the aortic intima in both the HPR and the LPR, using National Institutes of Health Image 1.47, an Apple Macintosh application capable of digital image processing, analysis, and morphometric measurement. There was significantly lower (P = 0.002, alpha = 0.05) TGF-beta 1 gene expression in the HPR than in the LPR in the 22- to 25-y age group. There was no significant difference in the 17- to 21-y age group and between the HPR and the LPR in the entire study group.(ABSTRACT TRUNCATED AT 250 WORDS)

Ionic contrast agent-mediated endothelial injury causes increased platelet deposition to vascular surfaces

Contrast agent-mediated endothelial injury may be clinically relevant to the development of acute thrombosis after coronary interventions. We sought to investigate the extent to which contrast agents increase platelet deposition by measuring deposition of indium-111 radiolabeled platelets in an isolated perfused rabbit carotid artery model. Carotid artery segments were perfused at physiologic temperature, pressure, and shear. Vessels were subjected to angioplasty or no angioplasty before exposure to either buffer, diatrizoate (high osmolal/ionic), ioxaglate (low osmolal/ionic), or ioversol (low osmolal/nonionic). Subsequent deposition of indium-111 radiolabeled platelets was quantified. In vessels without balloon angioplasty, platelet deposition (platelets/cm2) was 110,000 +/- 95,000 for buffer perfused vessels, 280,000 +/- 210,000 for vessels perfused with diatrizoate, 290,000 +/- 160,000 for vessels perfused with ioxaglate, and 130,000 +/- 98,000 for vessels perfused with ioversol. After balloon angioplasty, platelet deposition was 1,300,000 +/- 590,000 for buffer controls, 1,800,000 +/- 320,000 for diatrizoate-perfused vessels, 1,500,000 +/- 450,000 for ioxaglate-perfused vessels, and 1,000,000 +/- 180,000 for ioversol-perfused vessels. In vessels without balloon angioplasty, diatrizoate and ioxaglate increased platelet deposition 2.5-fold and 2.6-fold, respectively, relative to buffer-perfused vessels (p < 0.05 and p < 0.01), whereas no increase was seen with ioversol. After balloon angioplasty, diatrizoate increased platelet deposition 1.4-fold over control (p < 0.05), whereas ioxaglate and ioversol showed no statistically significant increase. We conclude that ionic contrast media may cause more endothelial injury and associated localized platelet deposition than nonionic contrast media. These findings may be relevant to coronary interventions, specifically with regard to acute closure and chronic restenosis.

[Intravenous treatment with streptokinase of acute myocardial infarction. II. Effect of patency of the artery supplying the infarction area on the infarction size and post-infarction impairement of left-ventricular function]

153 patients with a first acute myocardial infarction underwent the study. 90 of them received 1.000.000 units of streptokinase intravenously, followed by intravenous heparin administration for 5-7 days. The control group consisted of 63 remaining. In all patients serum CK-MB activity was determined every 4 hours for 72 hours: the infarct mass was calculated from the obtained curves. In 118 patients selective coronarography and left ventriculography was performed in the 2-nd or 3-rd week of hospitalisation. Left ventricular ejection fraction (E.F.) and dyssynergy index were calculated from ventriculographic data. Coronarography revealed a patent infarct-related artery in 76.7% of patients treated with streptokinase and in 44.4% of the control group (p less than 0.001). Among patients with a patent infarct-related artery an early peak of serum CK-MB activity (suggesting early recanalisation) occurred in 72.2% of streptokinase patients but in only 42.1% of the control group. Patients with a patent infarct-related artery had a significantly lower infarct mass (45 +/- 28 g vs 56 +/- 30 g), a lower left ventricular dyssynergy index (229 +/- 243 vs 348 +/- 247) and a significantly higher E.F. (63 +/- 12% vs 54 +/- 15%) compared with patients with an occluded artery.