Partial agenesis of the pectoralis major and minor muscle: A cadaveric case report.

RATIONALE: The pectoralis major and minor muscles, located in the anterior chest wall, are crucial for upper limb movements. PATIENT CONCERNS: Their nonsyndromic absence is rare but significant for surgical procedures involving the axillary and pectoral regions. DIAGNOSES: Ultrasound can confirm the diagnosis and delimit the extent of the muscular abnormality, detect abnormalities of the costal cartilages, among others. INTERVENTIONS: This descriptive, cadaveric case report involves a formalin-fixed 57-year-old North American male, with no clinical or family history of similar conditions. The study was conducted at the Human Anatomy Laboratory of the School of Medicine of the Universidad Finis Terrae in Santiago, Chile, in August 2022. OUTCOMES: We present a cadaveric case of bilateral partial agenesis of the pectoralis muscles discovered during routine dissection. The pectoralis major muscle exhibited only the clavicular portion, with the sternocostal and abdominal portions absent and replaced by a thin layer of connective tissue bilaterally. The pectoralis minor muscle showed partial muscle fibers only in the most distal and inferior portions bilaterally. LESSONS: This case report is significant due to the rarity of this condition without accompanying anatomical variations. Understanding this variant is valuable for clinical situations involving the shoulder and thorax region, such as trauma to the proximal third of the humerus, clavicular region, suprascapular region, and anterior chest wall. It may complicate conservative and/or surgical treatments due to different functional and irrigation patterns in the area and is also important for educating future professionals.

Axillary arch muscle and pectoralis quartus: an unusual combination of two variant supernumerary muscles in the axillary region - a case report.

Variant anatomy in the axillary region is of great clinical significance. It is one of the most frequently accessed regions for radical dissection surgery. During routine dissection of embalmed cadavers, we found a rare case of two accessory muscular slips emerging from the lateral border of latissimus dorsi (LD) and the inferolateral border of pectoralis major (PM), crossing the neurovascular structures in the axilla and merging distally together to the brachial fascia at the upper end of humerus below the bicipital groove. The accessory slip from LD is commonly referred to as the "axillary arch" in literature. We identified the accessory slip from the PM crossing over the axilla as pectoralis quartus. These aberrant slips can cause neurovascular compression in the axilla and can have clinical implications. Prior knowledge of the variant anatomy is the key to successful surgery in the axilla, thereby avoiding inadvertent injuries and post-operative complications.

A case report of bilateral atypical origin of pectoralis minor.

PURPOSE: In the existing literature, various insertion variations and classifications for the Pectoralis Minor (PMi) muscle have been reported. However, there is limited information on inferior origin variations of the PMi muscles and a certain classification is lacking. CASE PRESENTATION: During routine cadaver dissection of an adult male, variations in the origin of the bilateral PMi muscles were identified. Morphometric measurements of the PMi were conducted using ImageJ software, and the unusual origin patterns of the PMi were categorized into specific types. The PMi muscle demonstrated a bilateral variations. On the right side, the PMi displays a bifid structure comprising medial and lateral fibers. The left PMi originate from the superolateral margins of the 4th to 6th costae and terminate at the anterosuperior surface of the coracoid process. The length of the right medial fiber before merging was 5.67 ± 0.04 cm, while that of the right lateral fiber was 6.68 ± 0.05 cm. The distance between the two fibers was measured as 0.43 cm, with a length of 3.33 ± 0.02 cm. The length and diameter of the muscle fibers extending to the 6th costa were 2.63 ± 0.01 cm and 0.46 cm, respectively. CONCLUSIONS: Potential variations in PMi arising from impairment during development may occasionally manifest as asymptomatic conditions or predispose individuals to shoulder impingement, rotator cuff dysfunction, shoulder-related disorders, and functional impairments. Therefore, careful attention to this variation is considered in surgical planning.

Músculo Esternal Bilateral, Descripción de un Caso e Implicancias Clínicas / Bilateral Sternal Muscle, Description of a Case and Clinical Implications

El músculo esternal corresponde a una variante muscular supernumeraria de la musculatura torácica, cuya descripción más antigua se remonta al año 1604. A lo largo de la historia ha sido denominado músculo "epiesternal", "preesternal", "recto torácico" o "recto esternal". Se ubica entre la fascia superficial y el músculo pectoral mayor, tiene una prevalencia de entre 3 % y 8 % en la población general, se presenta de forma unilateral o bilateral exhibiendo una alta variabilidad interracial y puede ser motivo de dilemas diagnósticos durante cirugías y exámenes de imagen. Disección en un cadáver adulto de sexo masculino. Se encontraron dos músculos esternales conectados superiormente por un tendón central. El músculo esternal derecho se extendía desde el manubrio esternal hasta el séptimo cartílago costal derecho. El músculo esternal izquierdo se extendía desde el manubrio esternal hasta el sexto cartílago costal izquierdo. Su inervación estaba dada por ramos cutáneos anteriores de los nervios intercostales y su vascularización por ramas perforantes provenientes de los vasos torácicos internos. El músculo esternal presenta una alta variabilidad morfológica y su prevalencia se ve influenciada por factores raciales. Conocer esta variación muscular enriquece la capacidad diagnóstica y quirúrgica reduciendo la posibilidad de iatrogenia.

SUMMARY: The sternal muscle corresponds to a supernumerary muscle variant of the thoracic musculature, whose oldest description dates to 1604. Throughout history it has been called the "episternal", "presternal", "rectus thoracis" or "rectus sternalis" muscle. It is located between the superficial fascia and the pectoralis major muscle, has a prevalence of between 3 % and 8 % in the general population, presents unilaterally or bilaterally, exhibits a high interracial variability and can be the cause of diagnostic dilemmas during surgery and imaging examinations. Dissection in an adult male cadaver. Two sternal muscles were found connected superiorly by a central tendon. The right sternal muscle extended from the sternal manubrium to the right seventh costal cartilage. The left sternal muscle extended from the sternal manubrium to the left sixth costal cartilage. The innervation was given by anterior cutaneous branches of the intercostal nerves and the vascularization by perforating branches coming from the internal thoracic vessels. The sternal muscle presents a high morphological variability and the prevalence is influenced by racial factors. Knowing this muscle variation enriches the diagnostic and surgical capacity, reducing the possibility of iatrogenesis.

Delayed periprosthetic seroma in a male Poland syndrome patient: A case report.

RATIONALE: Custom-made implant is an accepted treatment option for treatment of chest deformity in Poland syndrome. Unlike the raised concerns and awareness for the long-term consequences of breast implants, the long-term complications of customized implants for special purposes like Poland syndrome has not been reported in the literature. PATIENT CONCERNS: A 44-year-old male with Poland syndrome presented to our institution complaining of a large bulge and fluctuation on the right chest wall. This occurred after 14 years from the initial implant surgery for correction of chest wall deformity. Upon failure of resolution by multiple aspirations, workup was carried out under suspicion of implant associated malignancy. INTERVENTION: Total Capsulectomy and implant removal was done. OUTCOMES: Histology revealed chronic inflammation with fibrosis. Implant-associated malignancy was not found. He is being followed up with no signs of recurrence. LESSONS: For rare cases of implant insertion such as Poland syndrome, awareness of delayed complications and workups based on suspicion of implant-associated malignancy is needed. Surgeon awareness and patient education is required.

Prevalence of anomalous or ectopic insertion of pectoralis minor: a systematic review and meta-analysis of 4146 shoulders.

INTRODUCTION: The proximal insertion beyond coracoid process of pectoralis minor is considered as hidden culprit of rotator cuff disorders. The ectopic insertion is also associated with thoracic outlet syndrome. The current review was conducted to provide a comprehensive evidence-based assessment of the anatomical characteristics of ectopic insertion of pectoralis minor. MATERIALS AND METHODS: A through systematic search was conducted on the major electronic database, PubMed, EMBASE, Google Scholar and Journals of Anatomy, orthopedics, plastic surgery, sports medicine. The primary outcome was to measure the prevalence of ectopic insertion of pectoralis minor tendons. The data extraction was conducted for pooled estimation and metanalysis. RESULTS: A total of 25 studies were included for systematic review. The overall pooled estimate of ectopic insertion of Pectoralis Minor was 19.27% (95% CI 15-24%). The prevalence rate in dissected specimen was 21% (CI 15-28%) and in arthroscopic evaluation was 22% (95% CI 5-59%) which was marginally higher with wide confidence interval due small sample size. The prevalence rate in MRI and USG were 15 and 12%, because MRI and USG have almost similar sensitivity in the detection of anomalous insertion of Pectoralis Minor. The distribution of subtypes of anomalous or ectopic insertion based on Le Double classification was 34% for type I, 42 and 9% for Type III. The incidence of ectopic insertion of pectoralis minor was highest in Japanese population. The female and left side have slightly higher incidence at insignificant level. CONCLUSION: The preoperative MRI or at least USG evaluation of shoulder joint must be conducted for appropriate surgical planning, because the prevalence of ectopic insertion is around 20%. The preoperative detection of anomalous insertion of pectoralis minor can be crucial in minimizing the incidences of iatrogenic injuries of tendon or post-operative complications.

63-year-old man with right biceps and right pectoralis major abscesses: an unusual case of pyomyositis.

Pyomyositis is considered a great mimicker and masquerader. This case is of a 63-year-old man with diabetes who initially presented to the outpatient clinic afebrile with right shoulder pain. His work-up was negative, and he was discharged home. He subsequently presented to the emergency room (ER) two times for worsening right shoulder pain. During his first visit to the ER, his work-up was unremarkable, and he was discharged home. On his return to the ER, he was now febrile with inflammation involving his right upper extremity and right chest wall. Imaging studies of his right upper extremity and his right chest wall were consistent with multiple abscesses. Methicillin resistant Staphylococcus aureus was cultured from the abscess, and from blood and urine cultures. The diagnosis of pyomyositis was confirmed. This case illustrates the difficulty of diagnosing pyomyositis and the importance of including it in the differential diagnosis, especially in an immunocompromised patient.

Anomalous insertion of the pectoralis minor tendon at the greater tuberosity.

We present a case of ectopic insertion of the whole tendon of the pectoralis minor muscle associated with impingement syndrome. Based on this case, we performed a review of the literature focused on the association between this ectopic tendon insertion and anterior shoulder pain.

Concomitant aortic root and pectus deformity repair in Marfan syndrome patients.

The role of concomitant aortic and pectus repair in Marfan patients remains controversial. We present our surgical technique for concomitant aortic repair of aortic root pathology and pectus correction. The concomitant surgery can be safely achieved in Marfan patients, thus, avoiding the need for a risky second stage operation.

Coexistence of a pectoralis quartus muscle, a supernumerary head of biceps brachii muscle and an accessory head of flexor digitorum profundus muscle.

Although anatomical variations in the upper limb are frequent, coexistence of multiple combined variations is rare. During a routine educational dissection at Jeju National University Medical School, three muscular variations were found in a 75-year-old Korean male cadaver, in which a supraclavicular cephalic vein was also found in ipsilateral upper extremity during skinning. Here we describe cha- racteristics of the pectoralis quartus muscle, the supernumerary head of biceps brachii muscle and an accessory head of flexor digitorum profundus muscle, and discuss their coexistence from morphological and embryological points of view.

Nonsyndromic Congenital Absence of the Pectoralis Muscles.

The congenital absence of the pectoralis muscle is usually a manifestation of Poland syndrome. However, a nonsyndromic congenital absence of this muscle is rare, and such absences are usually partial and unilateral. A complete or bilateral absence is even rarer. Two young men presented to our outpatient clinic with incidentally noted unilateral flat chest walls. By chest computed tomography, they were diagnosed with a congenital unilateral absence of the pectoralis muscles. They did not show any functional disability of the arms. As the congenital absence of the pectoralis muscles is often associated with leukemia and genitourinary anomalies, it is advised that hematological testing and renal ultrasonography be performed, even in nonsyndromic cases.

Poland syndrome accompanied by internal iliac artery supply disruption sequence: a case report.

BACKGROUND: Poland syndrome is a congenital malformation characterized by ipsilateral hand and chest wall depression, including an absence or hypoplasia of the breast and pectoral muscles. These hypoplastic defects are reportedly caused by a subclavian artery supply disruption sequence. CASE PRESENTATION: A 45-year-old Japanese woman, an out-patient, underwent an emergency examination for intense left lower abdominal pain. Computed tomography images revealed a hydronephrotic left kidney and dilatation of the left ureter. No ureteral calculus or neoplasm was found. In addition, no abnormalities connected to her left abdominal pain were found. Nephritis was diagnosed based on the results of urine analysis, and a course of antibiotics was administered. Computed tomography images also revealed a history of breast reconstruction with a custom-made silicone implant in her right breast. The present case showed symptoms of Poland syndrome, which were absence of the sternal head of the right pectoralis major and asymmetrical malformation of the chest wall due to hypoplasia of the right rib cage. In addition to typical Poland syndrome symptoms, she had hypoplasia of her right kidney, hypoplasia of the right gluteus minimus muscle, right-sided pelvic hypoplasia, spinal curvature to the right, and a cystic mass in her right ovary. CONCLUSIONS: In the present case of Poland syndrome, computed tomography images revealed malformation of the chest wall, absence of the pectoral muscle, and hypoplasia of a left kidney. Unilateral visceral hypoplasia is reported to be caused by a subclavian artery supply disruption sequence that occurs around 7 to 8 weeks of gestation. The present case can be considered a rare atypical phenotype of Poland syndrome with possible subclavian artery supply disruption sequence with internal iliac artery supply disruption.

The value of full-body skin examination: Poland syndrome diagnosed as an incidental finding.

Poland syndrome is a rare congenital disorder characterized by agenesis of the pectoralis major muscle. It is generally unilateral, right-sided, and can be associated with a myriad of thoracic and upper limb defects. Knowledge of this disorder can lead the astute clinician to prompt diagnosis and referral to surgical specialists for further workup. Surgery is often performed for either esthetic or functional concerns.

Serie de Casos: Síndrome de Poland Completo vs. Incompleto. Resolución Quirúrgica / Case Series: Poland Syndrome Complete vs Incomplete. Surgical Resolution

INTRODUCCIÓN: El síndrome de Poland es una enfermedad congénita polimalformativa extremadamente rara, su etiología es aún desconocida, afectando principalmente el desarrollo del músculo pectoral mayor; se acompañan frecuentemente de malformaciones de la mano, mama, complejo areola-pezón, pectoral menor ipsilateral y otras malformaciones asociadas. Su diagnóstico se basa en un correcto examen clínico junto con una tomografía axial computarizada con reconstrucción en 3D. El tratamiento quirúrgico final es individualizado y dependerá de la existencia de una o más malformaciones. CASOS CLÍNICOS: Se trató de cuatro pacientes con cuadro clínico compatible con síndrome de Poland, siendo común el subdesarrollo o ausencia del músculo pectoral mayor. EVOLUCIÓN: Se realizó a cada paciente una tomografía axial computarizada con reconstrucción en 3D para confirmar su diagnóstico y realizar un tratamiento quirúrgico según la necesidad de cada paciente, después del procedimiento se dio seguimiento a los pacientes con una respuesta favorable y sin complicaciones. CONCLUSIONES: El síndrome de Poland se caracteriza por un cuadro clínico variable, con la ausencia o subdesarrollo del músculo pectoral mayor, el tratamiento quirurgico fue personalizado para cada paciente. Las técnicas quirúrgicas incluyeron reconstrucción de la pared torácica mediante osteosíntesis en los casos graves independientemente del sexo del paciente; rotación de colgajos del músculo dorsal ancho, colocación de expansores tisulares y prótesis mamarias en el caso de las pacientes femeninas y colocación de prótesis preformadas mediante estereolitografía en el caso de los pacientes masculinos.

BACKGROUND: The Poland syndrome is an extremely rare polymalformative congenital disease, the etiology is still unknown, mainly affecting the development of the pectoralis major muscle; they are frequently accompanied by malformations of the hand, breast, nipple-areola complex, ipsilateral minor pectoral and other associated malformations. The diagnosis is based on a correct clinical examination together with a computerized axial tomography with 3D reconstruction. The final surgical treatment is individualized and will depend on the existence of one or more malformations. CASE REPORTS: Four patients with a clinical picture compatible with the Poland syndrome were treated, with underdevelopment or absence of the pectoralis major muscle being common. EVOLUTION: Each patient underwent a computerized axial tomography with 3D reconstruction to confirm their diagnosis and perform a surgical treatment according to the needs of each patient; after the procedure, patients were followed up with a favorable response and without complications. CONCLUSIONS: The Poland syndrome is characterized by a variable clinical picture, with the absence or underdevelopment of the pectoralis major muscle, the surgical treatment was customized for each patient. Surgical techniques included reconstruction of the chest wall by osteosynthesis in severe cases regardless of the sex of the patient; rotation of flaps of the latissimus dorsi muscle, placement of tissue expanders and mammary prosthesis in the case of female patients and placement of preformed prostheses by stereolithography in the case male patients.

Effect of white striping on turkey breast meat quality.

In the past decades, the intense selection practices carried out in order to develop fast growing and high breast-yield turkey hybrids profoundly modified the muscle physiology leading to the development of growth-related alterations and muscular abnormalities. White striations of variable thickness have been particularly observed on the ventral surface of Pectoralis major muscle belonging from heavy male turkeys since several years. However, although the effects of white striping (WS) have been extensively studied on broilers, this condition was not considered as a main quality issue by both turkey producers and meat industry. Thus, this study aimed at evaluating whether the occurrence of WS in heavy male turkeys affects the quality traits and technological properties of meat to the same extent previously observed for broilers. In two replications, 72 Pectoralis major muscles were classified as: normal (NORM), moderate WS (MOD) and severe WS (SEV) cases. The whole muscle was weighed and cut in order to assess colour, ultimate pH, water holding (drip and cooking losses) and binding (marinade uptake) capacities, NMR relaxation properties, shear force as well as proximate composition of meat. The Pectoralis major muscles affected by WS (both moderate and severe cases) exhibited a one-fifth increased weight in comparison with their NORM counterpart. However, the occurrence of WS only partially affected the proximate composition of the meat. In detail, although moisture, collagen and protein contents did not differ among the groups, if compared with NORM, higher lipid levels were found in SEV muscles, whereas MOD had intermediate values. On the other hand, both MOD and SEV exhibited lower ash content. Despite these variations in proximate composition, both water holding and binding capacities of turkey breast meat were not affected by WS. Indeed, quality traits of raw (pH, colour, cooking losses and shear force) and marinated (uptake, cooking losses and shear force) meat as well as water distribution within the muscle tissue did not differ between NORM and WS cases. Overall, if compared with broilers, WS only marginally affected quality traits of turkey breast meat. It might thus be hypothesised a diverse specie-specific physiological response to the pressure in muscle tissue induced by the selection in turkeys that, although analogously led to the occurrence of WS, results in limited effects on meat quality.

Controversies in Poland Syndrome: Alternative Diagnoses in Patients With Congenital Pectoral Muscle Deficiency.

PURPOSE: Poland syndrome was first described as a deficiency of the pectoral muscle with ipsilateral symbrachydactyly. Currently, numerous case reports describe variations of Poland syndrome in which pectoral muscle deficiency is often used as the only defining criterion. However, more syndromes can present with pectoral muscle deficiency. The aim of this review is to illustrate the diversity of the phenotypic spectrum of Poland syndrome and to create more awareness for alternative diagnoses in pectoral muscle deficiency. METHODS: A systematic literature search was performed. Articles containing phenotypical descriptions of Poland syndrome were included. Data extraction included number of patients, sex, familial occurrence, and the definition of Poland syndrome used. In addition, hand deformities, thoracic deformities, and other deformities in each patient were recorded. Alternative syndrome diagnoses were identified in patients with a combination of hand, thorax, and other deformities. RESULTS: One hundred-and-thirty-six articles were included, describing 627 patients. Ten different definitions of Poland syndrome were utilized. In 58% of the cases, an upper extremity deformity was found and 43% of the cases had an associated deformity. Classic Poland syndrome was seen in 29%. Fifty-seven percent of the patients with a pectoral malformation, a hand malformation, and another deformity had at least 1feature that matched an alternative syndrome. CONCLUSIONS: Pectoral muscle hypoplasia is not distinctive for Poland syndrome alone but is also present in syndromes with other associated anomalies with a recognized genetic cause. Therefore, in patients with an atypical phenotype, we recommend considering other diagnoses and/or syndromes before diagnosing a patient with Poland syndrome. This can prevent diagnostic and prognostic errors. CLINICAL RELEVANCE: Differentiating Poland syndrome from the alternative diagnoses has serious consequences for the patient and their family in terms of inheritance and possible related anomalies.