Principales tipos de quistes en dermatopatología: Parte 2 / Main Types of Cysts in Dermatopathology: Part 2

Este es el segundo artículo de una serie de dos publicados en esta revista, en los que examinamos las características histopatológicas, así como el diagnóstico diferencial, de las principales entidades que se presentan en forma de estructuras quísticas y pseudoquísticas en la biopsia cutánea. En este segundo artículo, abordamos los quistes cutáneo ciliado, branquial, de Bartholino, onfalomesentérico, tímico, del conducto tirogloso, sinovial, y del rafe medio, así como el mucocele, el ganglión y los pseudoquistes auricular y mixoide digital. (AU)

This is the second article in a two-part series published in this journal, in which we examine the histopathological characteristics, as well as the differential diagnosis, of the main entities that present as cystic and pseudocystic structures in cutaneous biopsy. In this second article, we address ciliated cutaneous cysts, branchial cysts, Bartholin's cysts, omphalomesenteric cysts, thymic cysts, thyroglossal duct cysts, synovial cysts, and median raphe cysts, as well as mucocele, ganglion, and auricular and digital myxoid pseudocysts. (AU)

Palsy of Both the Tibial Nerve and Common Peroneal Nerve Caused by a Ganglion Cyst in the Popliteal Area.

A ganglion cyst is a benign mass consisting of high-viscosity mucinous fluid. It can originate from the sheath of a tendon, peripheral nerve, or joint capsule. Compressive neuropathy caused by a ganglion cyst is rarely reported, with the majority of documented cases involving peroneal nerve palsy. To date, cases demonstrating both peroneal and tibial nerve palsies resulting from a ganglion cyst forming on a branch of the sciatic nerve have not been reported. In this paper, we present the case of a 74-year-old man visiting an outpatient clinic complaining of left-sided foot drop and sensory loss in the lower extremity, a lack of strength in his left leg, and a decrease in sensation in the leg for the past month without any history of trauma. Ankle dorsiflexion and great toe extension strength on the left side were Grade I. Ankle plantar flexion and great toe flexion were Grade II. We suspected peroneal and tibial nerve palsy and performed a screening ultrasound, which is inexpensive and rapid. In the operative field, several cysts were discovered, originating at the site where the sciatic nerve splits into peroneal and tibial nerves. After successful surgical decompression and a series of rehabilitation procedures, the patient's neurological symptoms improved. There was no recurrence.

A quality and readability comparison of artificial intelligence and popular health website education materials for common hand surgery procedures.

INTRODUCTION: ChatGPT and its application in producing patient education materials for orthopedic hand disorders has not been extensively studied. This study evaluated the quality and readability of educational information pertaining to common hand surgeries from patient education websites and information produced by ChatGPT. METHODS: Patient education information for four hand surgeries (carpal tunnel release, trigger finger release, Dupuytren's contracture, and ganglion cyst surgery) was extracted from ChatGPT (at a scientific and fourth-grade reading level), WebMD, and Mayo Clinic. In a blinded and randomized fashion, five fellowship-trained orthopaedic hand surgeons evaluated the quality of information using a modified DISCERN criteria. Readability and reading grade level were assessed using Flesch Reading Ease (FRE) and Flesch-Kincaid Grade Level (FKGL) equations. RESULTS: The Mayo Clinic website scored higher in terms of quality for carpal tunnel release information (p = 0.004). WebMD scored higher for Dupuytren's contracture release (p < 0.001), ganglion cyst surgery (p = 0.003), and overall quality (p < 0.001). ChatGPT - 4th Grade Reading Level, ChatGPT - Scientific Reading Level, WebMD, and Mayo Clinic written materials on average exceeded recommended reading grade levels (4th-6th grade) by at least four grade levels (10th, 14th, 13th, and 11th grade, respectively). CONCLUSIONS: ChatGPT provides inferior education materials compared to patient-friendly websites. When prompted to provide more easily read materials, ChatGPT generates less robust information compared to patient-friendly websites and does not adequately simplify the educational information. ChatGPT has potential to improve the quality and readability of patient education materials but currently, patient-friendly websites provide superior quality at similar reading comprehension levels.

Photoperiodism of Diapause Induction in the Silkworm, Bombyx mori.

The silkworm Bombyx mori exhibits a photoperiodic response (PR) for embryonic diapause induction. This article provides a comprehensive review of literature on the silkworm PR, starting from early works on population to recent studies uncovering the molecular mechanism. Makita Kogure (1933) conducted extensive research on the PR, presenting a pioneering paper on insect photoperiodism. In the 1970s and 80s, artificial diets were developed, and the influence of nutrition on PR was well documented. The photoperiodic photoreceptor has been investigated from organ to molecular level in the silkworm. Culture experiments demonstrated that the photoperiodic induction can be programmed in an isolated brain (Br)-subesophageal ganglion (SG) complex with corpora cardiaca (CC)-corpora allata (CA). The requirement of dietary vitamin A for PR suggests the involvement of opsin pigment in the photoperiodic reception, and a cDNA encoding an opsin (Boceropsin) was cloned from the brain. The effector system concerning the production and secretion of diapause hormone (DH) has also been extensively investigated in the silkworm. DH is produced in a pair of posterior cells of SG, transported to CC by nervi corporis cardiaci, and ultimately released into the hemolymph. Possible involvement of GABAergic and corazonin (Crz) signal pathways was suggested in the control of DH secretion. Knockout (KO) experiments of GABA transporter (GAT) and circadian clock genes demonstrated that GAT plays a crucial role in PR through circadian control. A model outlining the PR mechanism, from maternal photoperiodic light reception to DH secretion, has been proposed.

Tenoscopy for the Treatment of Hand Intratendinous Ganglion: Technique Description and Case Report.

Synovial or ganglion cysts are the most common soft tissue tumors of the wrist and hand and can arise from joints or tendons. Intratendinous synovial cysts, in contrast, are rare and their pathogenesis is still a matter of debate. The treatment of synovial cysts of articular origin using arthroscopy is commonly used with good results. For cysts of tendon origin, that is, extra-articular, when located at the ankle, shoulder, knee, and wrist, endoscopic treatment has also been described in a procedure called tenoscopy. We describe the technique and the good results using tenoscopy for a patient treated for an intratendinous synovial cyst located at the extensor communis tendon of the third digit. It is a reproducible, safe technique with low morbidity, and the patient has had no complications or recurrence.

An Updated Guide to the Identification, Quantitation, and Imaging of the Crustacean Neuropeptidome.

Crustaceans serve as a useful, simplified model for studying peptides and neuromodulation, as they contain numerous neuropeptide homologs to mammals and enable electrophysiological studies at the single-cell and neural circuit levels. Crustaceans contain well-defined neural networks, including the stomatogastric ganglion, oesophageal ganglion, commissural ganglia, and several neuropeptide-rich organs such as the brain, pericardial organs, and sinus glands. As existing mass spectrometry (MS) methods are not readily amenable to neuropeptide studies, there is a great need for optimized sample preparation, data acquisition, and data analysis methods. Herein, we present a general workflow and detailed methods for MS-based neuropeptidomic analysis of crustacean tissue samples and circulating fluids. In conjunction with profiling, quantitation can also be performed with isotopic or isobaric labeling. Information regarding the localization patterns and changes of peptides can be studied via mass spectrometry imaging. Combining these sample preparation strategies and MS analytical techniques allows for a multi-faceted approach to obtaining deep knowledge of crustacean peptidergic signaling pathways.

Ultrastructural study of neuronal cells and localization of ghrelin-like peptide and its receptor in the ganglia of the golden apple snail (Pomacea canaliculata).

Pomacea canaliculata is an invasive snail species causing major problems in agriculture. The snail biology was then investigated. The main objective of the present study was to investigate the nervous system of the snail. The nervous system comprises pairs of cerebral, buccal, pedal, pleural, parietal ganglia and an unpaired visceral ganglion. Most neurons were concentrated at the periphery of the ganglia. The neurons were classified into four types: NR1, NR2, NR3, and NR4. The percentages of the NR3 and NR4 in the pleural and pedal ganglia were significantly higher than those of other ganglia. Ultrastructural study revealed that nuclei of all neuronal types exhibited mostly euchromatins. Many organelles including ribosomes and endoplasmic reticulum were found in their cytoplasm. However, various mitochondria were found in the NR2 and NR3. The immunohistochemistry revealed immunoreactivity of ghrelin-like peptide in the neurons of the cerebral, pleural and pedal ganglia. However, immunoreactivity of GHS-R1a-like peptide existed only in the neurons of the pleural and pedal ganglia. The present study is the first to demonstrate the existence of ghrelin-like peptide and its receptor in P. canaliculata nervous system.

Lessons in clinical reasoning - pitfalls, myths, and pearls: a case of tarsal tunnel syndrome caused by an intraneural ganglion cyst.

OBJECTIVES: Intraneural ganglionic cysts are non-neoplastic cysts that can cause signs and symptoms of peripheral neuropathy. However, the scarcity of such cases can lead to cognitive biases. Early surgical exploration of space occupying lesions plays an important role in identification and improving the outcomes for intraneural ganglionic cysts. CASE PRESENTATION: This patient presented with loss of sensation on the right sole with tingling numbness for six months. A diagnosis of tarsal tunnel syndrome was made. Nerve conduction study revealed that the mixed nerve action potential (NAP) was absent in the right medial and lateral plantar nerves. The magnetic resonance imaging (MRI) found a cystic lesion measuring 1.4×1.8×3.8 cm as the presumed cause of the neuropathy. Surgical exploration revealed a ganglionic cyst traversing towards the flexor retinaculum with baby cysts. The latter finding came as a surprise to the treating surgeon and was confirmed to be an intraneural ganglionic cyst based on the histopathology report. CONCLUSIONS: Through integrated commentary by a case discussant and reflection by an orthopedician, this case highlights the significance of the availability heuristic, confirmation bias, and anchoring bias in a case of rare disease. Despite diagnostic delays, a medically knowledgeable patient's involvement in their own care lead to a more positive outcome. A fish-bone diagram is provided to visually demonstrate the major factors that contributed to the diagnostic delay. Finally, this case provides clinical teaching points in addition to a pitfall, myth, and pearl related to availability heuristic and the sunk cost fallacy.

The sternoclavicular ganglion cyst, a rare pediatric diagnosis.

We briefly describe the case of a 4-year-old girl, referred for imaging of a small, firm, round, skin-colored, subcutaneous nodule that suddenly appeared at her right sternoclavicular junction. A plain radiograph was non-contributory, but ultrasonography revealed a small cystic structure, leading to the diagnosis of a sternoclavicular ganglion cyst. Sternoclavicular ganglion cysts are a rare diagnosis, with only seven reported pediatric cases. A watchful waiting approach can be adopted so long as they remain asymptomatic.

ISL1 and POU4F1 Directly Interact to Regulate the Differentiation and Survival of Inner Ear Sensory Neurons.

The inner ear sensory neurons play a pivotal role in auditory processing and balance control. Though significant progresses have been made, the underlying mechanisms controlling the differentiation and survival of the inner ear sensory neurons remain largely unknown. During development, ISL1 and POU4F transcription factors are co-expressed and are required for terminal differentiation, pathfinding, axon outgrowth and the survival of neurons in the central and peripheral nervous systems. However, little is understood about their functional relationship and regulatory mechanism in neural development. Here, we have knocked out Isl1 or Pou4f1 or both in mice of both sexes. In the absence of Isl1, the differentiation of cochleovestibular ganglion (CVG) neurons is disturbed and with that Isl1-deficient CVG neurons display defects in migration and axon pathfinding. Compound deletion of Isl1 and Pou4f1 causes a delay in CVG differentiation and results in a more severe CVG defect with a loss of nearly all of spiral ganglion neurons (SGNs). Moreover, ISL1 and POU4F1 interact directly in developing CVG neurons and act cooperatively as well as independently in regulating the expression of unique sets of CVG-specific genes crucial for CVG development and survival by binding to the cis-regulatory elements including the promoters of Fgf10, Pou4f2, and Epha5 and enhancers of Eya1 and Ntng2 These findings demonstrate that Isl1 and Pou4f1 are indispensable for CVG development and maintenance by acting epistatically to regulate genes essential for CVG development.

Spontaneous resolution of spinoglenoid ganglion cyst: a case series.

BACKGROUND: Spontaneous resolution of a spinoglenoid notch ganglion cyst (SGC) without surgical treatment has been rarely reported; however, we have encountered this phenomenon occasionally. Therefore, we aimed to describe a case series of consecutive patients with SGC in whom it spontaneously resolved without surgical treatment. METHODS: We retrospectively reviewed 12 patients with magnetic resonance imaging (MRI)-confirmed SGC in whom it resolved without surgical treatment between January 2011 and March 2023. We included patients without abnormally increased signal intensity or muscle atrophy due to denervation from suprascapular neuropathy on MRI. Resolution of the SGC was confirmed via MRI or ultrasound at the follow-up visit, and suprascapular neuropathy was assessed using electromyography and nerve conduction studies when needed. For functional assessments, the visual analog scale for pain and active range of motion of the shoulder were used to compare pre and postresolution follow-ups. RESULTS: Eleven men and 1 woman with a median age of 54.0 years (interquartile range [IQR] 37.0-65.3) were included in this study. The SGCs resolved spontaneously at a median of 13.2 months with an IQR of 8.2-23.0 after initial evaluation using MRI. The SGCs were multiloculated cysts with superior labrum anterior and posterior II-IX lesions, with a median diameter of 2.5 cm (IQR 2.0-2.8). The median visual analog scale for pain (pre-resolution 5.0 [IQR 4.0-7.0] vs postresolution 1.0 [IQR 0.0-1.0], P = .002) and internal rotation at the back (preresolution 8.0 [IQR 7.0-10.3] vs postresolution 7.5 [IQR 7.0-8.0], P = .034) were significantly improved after the resolution. CONCLUSIONS: Surgical treatment may not be necessary in all cases of SGC. Nonsurgical treatment may be a viable option in the absence of suprascapular nerve involvement or superior labrum anterior and posterior-related physical findings.

A Modified Approach for Arthroscopic Excision of Dorsal Midcarpal Ganglion Cysts Using Radiocarpal Portals.

Wrist arthroscopy could be a treatment option for dorsal ganglion cysts. To achieve a thorough dorsal capsulectomy for the removal of midcarpal ganglion cysts, it is commonly necessary to combine both the radiocarpal and midcarpal portals. We present a modified method using radiocarpal portals only for arthroscopically excising dorsal midcarpal ganglion cysts. No extra midcarpal portals are necessary, and the method potentially generates satisfactory results.

Role of serotonin in the lack of sensitization caused by prolonged food deprivation in Aplysia.

Food deprivation may cause neurological dysfunctions including memory impairment. The mollusk Aplysia is a suitable animal model to study prolonged food deprivation-induced memory deficits because it can sustain up to 14 days of food deprivation (14DFD). Sensitization of defensive withdrawal reflexes has been used to illustrate the detrimental effects of 14DFD on memory formation. Under normal feeding conditions (i.e., two days food deprivation, 2DFD), aversive stimuli lead to serotonin (5-HT) release into the hemolymph and neuropil, which mediates sensitization and its cellular correlates including increased excitability of tail sensory neurons (TSNs). Recent studies found that 14DFD prevents both short-term and long-term sensitization, as well as short-term increased excitability of TSNs induced by in vitro aversive training. This study investigated the role of 5-HT in the absence of sensitization and TSN increased excitability under 14DFD. Because 5-HT is synthesized from tryptophan obtained through diet, and its exogeneous application alone induces sensitization and increases TSN excitability, we hypothesized that 1) 5-HT level may be reduced by 14DFD and 2) 5-HT may still induce sensitization and TSN increased excitability in 14DFD animals. Results revealed that 14DFD significantly decreased hemolymph 5-HT level, which may contribute to the lack of sensitization and its cellular correlates, while ganglia 5-HT level was not changed. 5-HT exogenous application induced sensitization in 14DFD Aplysia, albeit smaller than that in 2DFD animals, suggesting that this treatment can only induce partial sensitization in food deprived animals. Under 14DFD, 5-HT increased TSN excitability indistinguishable from that observed under 2DFD. Taken together, these findings characterize 5-HT metabolic deficiency under 14DFD, which may be compensated, at least in part, by 5-HT exogenous application.

Arthroscopic Dorsal Ligamentocapsulodesis in the Treatment of Occult Dorsal Wrist Ganglion Cysts Associated with Scapholunate Instability: Surgical Technique and Preliminary Clinical Results.

Background: This study aimed to evaluate our preliminary results and experience with the arthroscopic dorsal ligamentocapsulodesis in managing occult dorsal wrist ganglion cysts (ODGCs) associated with scapholunate (SL) instability. Methods: All patients who underwent arthroscopic dorsal ligamentocapsulodesis due to an ODGC with concomitant SL ligament tear were retrospectively reviewed. In addition to demographic data and length of follow-up, outcomes data that included range of motion, grip strength, modified Mayo wrist score (MMWS), complications and radiographs were collected. Results: The study included 18 patients (18 wrists; 10 female and 8 male). The mean age was 32 years (range: 19-48) and the mean follow-up was 34 months (range: 24-48). The mean preoperative extension deficit decreased from 5.5° (range: 0°-20°) to 2.7° (range: 0°-15°) at the final follow-up (p = 0.004). The mean preoperative flexion deficits decreased from 4.4° (range: 0°-15°) to 2.2° (range: 0°-10°) postoperatively (p = 0.003). The mean hand grip strength significantly increased from 27.7 kg (range: 22-36) to 38.3 kg (range: 31-46) at the final follow-up assessment (p < 0.001). The mean MMWS improved from 46 (range: 25-65) pre-operatively to 91 (range: 70-100) at the final follow-up (p = 0.0002). No major intra- or postoperative complications were observed. Conclusions: SL instability may have an important role in the aetiology of ODGCs, and arthroscopic dorsal ligamentocapsulodesis can provide pain relief and functional improvement without recurrence at the short- to mid-term follow-up in the treatment of ODGCs. Level of Evidence: Level IV (Therapeutic).

CUBITAL TUNNEL SYNDROME DUE TO AN INTRANEURAL GANGLION CYST OF THE ULNAR NERVE.

Cubital tunnel syndrome is the second most common neuropathy of the upper extremity. Cubital tunnel syndrome caused by intraneural ganglion cysts is rare in clinical practice. We present the case of a 71-year-old male patient with a 4-month history of cubital tunnel syndrome of the left elbow due to an intraneural ganglion cyst. After revision of the ulnar nerve and resection of the intraneural cyst nearly complete recovery was achieved within a 5 month follow-up but some sensory deficits of the fifth fingertip. We recommend preoperative ultrasound examination of the cubital tunnel even in cases with clear diagnosis. Ganglion cyst as a cause of cubital tunnel is rare but needs to be diagnosed and treated as soon as possible to prevent irreversible complications.

AN INTRATENDINOUS GANGLION CYST OF THE PATELLAR TENDON: A RARE CAUSE OF ANTERIOR KNEE PAIN.

Ganglion cysts in the knee region can manifest as anterior knee pain. Unlike synovial cysts, these lesions lack synovial epithelial lining and occur secondary to mucoid degeneration of connective tissue because, often in response to chronic irritation and repetitive traumas. However, an intratendinous location is a rare finding. In the knee region, infrapatellar fat pad, the alar folds, and the anterior cruciate ligament are recognized to degenerate into ganglion. There are few case reports describing an involvement of the patellar tendon. We present the clinical case of a 72 years old male patient suffering from anterior knee pain attributed to an intratendinous ganglion cyst of the patellar tendon, obviously after a single traumatic event. After aspiration of the ganglion cyst the patient reported no complaints, and there has been no recurrence during the latest follow-up examination.

Digital mucous cysts of the finger without osteoarthritis: optimizing outcome of long needle trajectory aspiration and injection.

Digital mucous cysts are common, benign and highly recurrent tumors of the distal interphalangeal joints of the fingers and often associated with osteoarthritis. Multiple treatment modalities have been described, but still no consensus is stated. In the absence of degenerative changes, we promote a novel non-surgical approach. The aim of this study was to examine all patients with digital mucous cysts without underlying osteoarthritis, undergoing this injection technique and to assess outcome and complications of this procedure. This was a single center study (2018-2019) of 17 patients who received a long needle trajectory aspiration and injection for treatment of digital mucous cysts. Exclusion criteria were prior surgical treatment, post-traumatic cyst formation and the presence of radiographic distal interphalangeal joint osteophytosis. A total of 15 patients were found eligible for inclusion. The patient reports were retrospectively analyzed with a follow-up of 6 months. The primary study outcome was resolution of the cyst; secondary outcomes were complications of the procedure. Twelve (80%) resolved completely and three (20%) had limited local recurrence at 6 months. No complications were reported. None of the patients with limited recurrence desired further treatment. We believe that this technique offers a non-invasive, low-cost treatment option for digital mucous cysts, particularly in the subset of patients with ample evidence of degenerative articular changes in the distal interphalangeal joint. The described technique can be performed in an office-based setting and avoids typical surgical as well as aspiration-associated complications.