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Patient Presentation
Pediatric residents and their attending pediatrician were discussing a new adolescent oncology patient admission. The teen was diagnosed with lymphoma after presenting with cough, fever and fatigue, and who had mediastinal lymphadenopathy. The attending remarked that lymphoma was common in this age group and also a common cause of anterior mediastinal tumors. “Remember your 4T’s, but thymoma is rare,” he said. “Then why do we always talk about it so much?” asked one of the residents. “I think that’s funny too. Thymoma is rare in kids, but more common in adults. I always think about tumors starting with what is the likely organ it is arising from, then what organs are around in that space like the mediastinum, lungs, abdomen etc. Then what else commonly would metastasize to this area, and then of course, there is always bones and soft tissues that can have tumors arise from them like sarcomas or lipomas or hemangiomas. In this case, the thymus is one of those organs in the area and therefore you have to think about it as a potential cause. Oh, I should also throw in, remember to include infections like tuberculosis or fungal infections infiltrating into tissues which can look like masses, or even diseases like sarcoid. Less common, but like thymomas you should think about potential causes, although we start to work up more likely causes first just because they occur more often. Rare diseases happen rarely but do happen. In this patient’s case, he has mediastinal adenopathy, but also other nodes that we were able to more easily biopsy and therefore make the lymphoma diagnosis,” he discussed.

Figure 149 shows Hodgkin Lymphoma

Discussion
Thymomas are rare pediatric tumors. They can present at all ages from infancy to > 90 years but most occur in the 4th to 5th decades with 10% of thymomas diagnosed in those in the pediatric age range. There are approximately 80 cases of pediatric thymomas in the literature based on a 2022 comprehensive literature review spanning 1985-2020. In this and a 2014 review, males are more commonly affected than females in the pediatric age range, but in adults the genders are about the same percentage or have a slight female predominance.

Thymomas are associated with paraneoplastic processes including presentation with myasthenia gravis. Of pediatric patients with thymomas, 5-15% have been reported as having myasthenia gravis. For adult patients with a thymoma, 30% will develop myasthenia gravis. For those adult patients presenting with myasthenia gravis, 10% will have a thymoma. Overall most thymomas are generally indolent and often present for workup of another condition. However mass effect in the chest (e.g. cough, dyspnea, superior vena cava syndrome) can be a presentation especially in small children.

Learning Point
Thymic tumors include:

Thymoma

Thymic carcinomas

Anterior mediastinal tumors are usually remembered by the 4T’s of thymoma, teratoma, thyroid and “terrible” lymphoma. Germ cell tumors and lymphomas are most common. The differential diagnosis includes:

• Germ cell tumors such as teratomas and a variety of benign and malignant tumors of different cell types
• Lymphoma – Hodgkin’s lymphoma is most common.
• Thymic neoplasms – 15% with thymoma being the most common (about 4% of pediatric mediastinal tumors).
• Aberrant thyroid tissue and goiter
• Parathyroid adenoma
• Hemangioma
• Lipomas
• Sarcomas

Questions for Further Discussion
1. Explain the function of the thymus?
2. What is the name of the radiologic sign which shows the thymus on an infant chest radiograph?
3. What are the different types of myasthenia gravis? A review can be found here.
4. Describe the mediastinal spaces? A review can be found here.
5. What are the most common pediatric tumors? A review can be found here.

Related Cases

Disease: Lymphoma | Thymus Cancer

Symptom/Presentation: Cough | Fatigue | Fever and Fever of Unknown Origin | Mass or Swelling

Specialty: Oncology

Age: Teenager

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.

Information prescriptions for patients can be found at MedlinePlus for these topics: Lymphoma, Thymus Cancer, and Myasthenia Gravis.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Yalcin B, Demir HA, Ciftci AO, et al. Thymomas in Childhood: 11 Cases From a Single Institution. Journal of Pediatric Hematology/Oncology. 2012;34(8):601-605. doi:10.1097/MPH.0b013e31825808e9

Fonseca AL, Ozgediz DE, Christison-Lagay ER, Detterbeck FC, Caty MG. Pediatric thymomas: report of two cases and comprehensive review of the literature. Pediatr Surg Int. 2014;30(3):275-286. doi:10.1007/s00383-013-3438-x

Rossi C, Zanelli M, Sanguedolce F, et al. Pediatric Thymoma: A Review and Update of the Literature. Diagnostics (Basel). 2022;12(9):2205. doi:10.3390/diagnostics12092205

Myasthenia gravis and congenital myasthenic syndromes. In: Handbook of Clinical Neurology. Vol 195. Elsevier; 2023:635-652. doi:10.1016/B978-0-323-98818-6.00010-8

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa

Patient Presentation
A former 34 week gestation male who was now 4 months corrected gestational age was seen for his health maintenance visit. He had transitioned to regular formula feeding at 2 months and was taking his bottle well. His mother had not attempted solid foods. He had good head control in a prone position and was making cooing sounds. He was not consistently rolling over or using his hands at midline. He was stooling and urinating freely. The past medical history was positive for an isolated epispadias.

The pertinent physical exam showed a happy male who was developmentally appropriate for a 2 month old and his corrected gestational age. His growth parameters showed him now to be caught up and on the CDC growth charts he was growing at the 10%. He had a normal physical examination except that the dorsal base of the penis was his urethral opening. A mild curvature to the phallus was also noted.

The diagnosis of of a healthy male, former premature infant with isolated epispadias was made. His mother said that the pediatric urologist was happy with his growth and therefore would be scheduling his surgery soon.

Discussion
The exstrophy-epispadias complex (EEC) is a spectrum of congenitally acquired malformations that affect the urogenital, gastrointestinal and musculoskeletal systems. The most common is classic bladder exstrophy (BE) which occurs in 2.2-3.3 per 100,000 live births. Males are more affected than females. In addition to epispadias, the bladder plate is exposed and lies outside the abdominal wall. Cloacal exstrophy (CE) is the severest form of EEC. It is usually associated with an omphalocoele with multiple organs extending beyond the abdominal wall and are covered by a tissue sac. There can be numerous additional anomalies within CE including kidney abnormalities, duplicated reproductive systems, imperforate anus, and spinal and pelvic bony abnormalities.

BE and CE treatment requires a multidisciplinary team that can plan and carry out the often extensive and multiple surgeries necessary and appropriate pre- and after-care to achieve goals along with the patient and family. As they are complex surgeries, they have a higher rate of anticipated and actual complications. The goals of treatment include urinary and bowel continence and normal organ system growth, normal kidney function, and normal sexual function along with normal psychosocial function. Particular goals may have more importance depending on the patient’s age. Genital hygiene may be more of an issue for a young school age child who needs assistance, whereas a teenager or young adult is likely to be more concerned with sexual functioning.

Initial surgeries are usually performed in young children. Longer-term data supports that youth and young adults who had EEC surgeries were overall satisfied with their parents’ decision to have the surgery(ies) performed. “No decisional regret was found in parents. Reinterventions were associated with a decline in satisfaction, as was a decrease in perceived penile length.” Males with EEC overall have shorter and wider phalluses. Phalloplasty can offer some help for some patients but does have a high complication rate. Females with EEC may have more pregnancy related problems including increased risk of urinary tract infections, miscarriages, and genital prolapse.

Learning Point
Isolated epispadias is the mildest form of EEC and occurs in about 1 per 200,000 births. The urethra is not fully formed and in males “… is open at the dorsal side of the short and curved phallus”, while in females the urethra lies between a bifid clitoris. As this is isolated, the repair is usually less extensive than with BE or CE, but still can have complications.

Questions for Further Discussion
1. How common is hypospadias? A review can be found here.
2. What is normal phallus size? A review can be found here
3. What are common causes of splayed urinary stream? A review can be found here

Related Cases

Disease: Epispadias | Penis Disorders

Symptom/Presentation: Health Maintenance and Disease Prevention

Specialty: Nephrology / Urology

Age: Infant

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews. Information prescriptions for patients can be found at MedlinePlus for these topics: Penile Disorders and Urethral Disorders.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Dunn EA, Kasprenski M, Facciola J, et al. Anatomy of Classic Bladder Exstrophy: MRI Findings and Surgical Correlation. Curr Urol Rep. 2019;20(9):1-7. doi:10.1007/s11934-019-0916-2

Sinatti C, Schechter MY, Spinoit AF, Hoebeke P. Long-term outcome of urethral and genital reconstruction in hypospadias and exstrophy-epispadias complex. Curr Opin Urol. 2021;31(5):480-485. doi:10.1097/MOU.0000000000000920

Haddad E, Hayes LC, Price D, Vallery CG, Somers M, Borer JG. Ensuring our exstrophy-epispadias complex patients and families thrive. Pediatr Nephrol. 2024;39(2):371-382. doi:10.1007/s00467-023-06049-y

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa

Patient Presentation
A 15-year-old female came to clinic for her health maintenance examination. She was overall well but had been diagnosed in the emergency room 4 weeks previously with an enlarged left ovarian cyst of 11 ml in volume. The ovarian cyst was noted incidentally during an evaluation for abdominal pain. The abdominal pain had been consistent with gastroenteritis and had resolved in the interim, and she was well during the visit. The past medical history showed she had menarche at age 12 with regular menstrual cycles.

The pertinent physical exam revealed a healthy female with normal vital signs and growth parameters of 25-75%. Her examination was normal.

The diagnosis of a healthy female with an enlarged left ovarian cyst was made. As the ultrasound characteristics were of a benign functional cyst, the patient was to be monitored and have repeat ultrasound after 3 menstrual cycles. Two months later she had a normal pelvic ultrasound and the cyst was now only 3 ml in volume in size, well below the normal volume.

Discussion
Ovarian masses are classified as non-neoplastic vs neoplastic.
Non-neoplastic masses are the most common and are follicular (simple), hemorrhagic, corpus luteum or paratubal cysts. These are 25-69% of all adnexal masses.
Neoplastic ovarian masses in children and adolescents are usually benign (about 90% of all neoplastic causes) and occur in 2.6 per 100,000 girls. Examples are mature teratomas and cystadenomas.
Neoplastic ovarian masses in children occur in about 10% of all neoplastic masses. They include immature teratomas, dysgerminomas, yolk sac tumors, granulosa cell tumors and borderline tumors.

Ovarian masses are usually found because of evaluation for abdominal pain, abnormal growth or puberty, or being incidentally noted on radiographic imaging. Treatment depends on clinical symptoms. As most masses are non-neoplastic and those that are neoplastic commonly are benign, conservative monitoring, and/or conservative surgical procedures are the most common and preferred treatment. Functional cysts often resolve within 2-3 menstrual cycles like the patient above, and therefore close monitoring and repeated imaging is often the treatment plan for presumed functional ovarian cysts.

Large masses can have an increased risk of ovarian torsion and therefore any patient with an enlarged ovarian mass should be counseled regarding symptoms to return to the emergency room for. A review of ovarian torsion can be found here.

Polycystic ovarian syndrome is also a cause of ovarian cysts. A review can be found here.

Learning Point
Ovarian volume is measured on 3 axes (length, width, height) and then volume is calculated by multiplying the 3 measurements and a constant of 0.52.

Normal ovarian volume for a neonate is 1 ml, in prepubertal females is up to 3 ml and in post-pubertal adolescent females is 6 ml. Normal, non-pregnant adult women ovarian volume is also 6 ml. The volume can be different between each ovary. There can also be a range of normal volumes and deciding what is normal vs. abnormal therefore can be more difficult.

In adult women, values that are 2 standard deviations above the mean for ovarian volume are:

“14-15 mL at <30 years of age
13 mL in the 30s
11 mL in the 40s
5-6 mL in the 50s
4-5 mL above 60 years of age”

Questions for Further Discussion
1. What causes abdominal pain? A review can be found here.
2. What is the normal range for menarche in normal girls?
3. What are the clinical signs and symptoms for McCune-Albright syndrome?

Related Cases

Disease: Ovarian Cysts

Symptom/Presentation: Abdominal Pain | Health Maintenance and Disease Prevention

Specialty: Obstetrics / Gynecology | Radiology / Nuclear Medicine / Radiation Oncology

Age: Teenager

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews. Information prescriptions for patients can be found at MedlinePlus for these topics: Ovarian Cysts and Ovarian Disorders.

To view current news articles on this topic check Google News.

To view images related to this topic check Google Images.

To view videos related to this topic check YouTube Videos.

Papanikolaou A, Michala L. Autonomous Ovarian Cysts in Prepubertal Girls. How Aggressive Should We Be? A Review of the Literature. Journal of Pediatric and Adolescent Gynecology. 2015;28(5):292-296. doi:10.1016/j.jpag.2015.05.004

Management of benign ovarian lesions in girls: a trend toward fewer oophorectomies – PubMed. Accessed September 9, 2025. https://pubmed-ncbi-nlm-nih-gov.proxy.lib.uiowa.edu/28759460/

Stankovic Z. Ovarian Cysts and Tumors in Adolescents. Obstetrics and Gynecology Clinics of North America. 2024;51(4):695-710. doi:10.1016/j.ogc.2024.08.006

Ovary size and volume | Radiology Reference Article | Radiopaedia.org. Accessed September 9, 2025. https://radiopaedia.org/articles/ovary-size-and-volume?lang=us

Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa