Skeletal development of achondroplasia: analysis of genotyped patients

Radiological characteristics of skeletal growth in neonates and infants with achondroplasia

Achondroplasia (ACH) is the most common form of skeletal dysplasia characterized by a rhizomelic short stature. Radiological skeletal findings in pediatric and adult patients with ACH include short long bones, a relatively longer fibula compared to the tibia, a narrow lumbar interpedicular distance, and a hypoplastic iliac wing. Nonetheless, the characteristics of skeletal growth during the neonatal and infantile periods have scarcely been explored. Therefore, this retrospective study aimed to analyze the radiological skeletal growth during the neonatal and infantile periods in 41 Japanese patients with genetically confirmed ACH. The length of long bones in the upper and lower limbs and the lumbar interpedicular distances at L1 and L4 were measured. These parameters showed significant positive correlations with age. The upper segment-to-lower segment ratio in the lower limbs resembled the data of healthy controls from previous reports. The L1/L4 and fibula/tibia ratios increased with age, suggesting that some representative skeletal phenotypes of ACH were less distinct during the neonatal and infantile periods. In conclusion, for the first time, this study radiologically characterized skeletal growth during the neonatal and infantile periods of patients with genetically confirmed ACH.

Prostate biopsy free system for laparoscopic radical prostatectomy in a pituitary dwarfism: a case report

Prostate biopsy is the gold standard for the diagnosis of prostate cancer. However, not all patients are suitable for prostate biopsy. For example, some patients have anal stenosis, some patients are too old to withstand the pain caused by puncture, patients who are unwilling to undergo prostate biopsy. We found that there was currently no literature report on a specific solution to this problem. This is the first report of a laparoscopic radical prostatectomy (LRP) in a pituitary dwarfism who didn’t have a prostate biopsy before LRP due to anal stenosis. And this report added a new method to diagnose prostate cancer. We present a case of a 61-year-old pituitary dwarfism who had a prostate specific antigen (PSA) of 32.13 ng/mL by physical examination and didn’t perform prostate biopsy due to anal stenosis. Preoperative prostate MRI suggests a low-signal mass on the left side of the prostate and ⁶⁸Ga PSMA-11 PET/CT demonstrated that Abnormally high PSMA and CHO uptake on the left side of the prostate. Therefore, combined with the patient’s PSA, MRI and ⁶⁸Ga PSMA-11 PET/CT, our clinical diagnosis was prostate cancer. Surgery was difficult due to narrow pelvic space, but achievable through LRP. Histological analysis revealed multifocal prostate cancer, with negative surgical margins and no extraprostatic extension. Postoperative patient had no serious complications and was discharged. Based on this case, For the first time, we proposed to make full use of the results of clinical tests and imaging examinations for the diagnosis and treatment of diseases without prostate biopsy.

Achondroplasia: Really rhizomelic?

Achondroplasia is the most common form of short limb dwarfism in humans. The shortening of the limb lengths in achondroplasia is widely described as "rhizomelic." While this appearance may be convincing clinically, the description is not necessarily true or helpful radiologically. The aims of this study, were therefore, to determine whether rhizomelic shortening is a true feature of achondroplasia at diagnosis in infancy. Humeral, radial, femoral, and tibial diaphyseal lengths were recorded by two independent observers from 22 skeletal surveys of infants with achondroplasia and compared with 150 normal age-matched control subjects. Upper and lower limb bone length ratios (radial/humeral and tibial/femoral lengths, respectively) in both groups were compared using an unpaired t-test. Mean upper limb length ratios were statistically higher within the achondroplasia group at 0.87 ± 0.04 (n = 22, mean age 70 ± 94 days) compared to normal controls at 0.79 ± 0.02 (n = 150, mean age 113 days ± 88 days; P < 0.0001). Lower limb length ratios were not significantly different between groups (0.84 ± 0.04 vs. 0.83 ± 0.02, P = 0.46). There was good inter-observer agreement of limb length measurements, with an average measurement difference of 0.1 ± 1.4 mm. In conclusion, infants with achondroplasia demonstrate statistically significant rhizomelic shortening within the upper limbs, but not lower limbs at diagnosis, compared to normal controls. The term "rhizomelic shortening" in relation to achondroplasia should be reserved when describing upper limb proportions. © 2016 Wiley Periodicals, Inc.

Severe complications in a child with achondroplasia and twoFGFR3 mutations on the same allele

We describe a unique case of achondroplasia with associated complications, including severe respiratory problems. Molecular analysis of the fibroblast growth factor receptor type 3 (FGFR3) gene in this patient showed the common p.G380R mutation and a second novel p.L377R mutation. An allele-specific PCR demonstrated that these mutations were on the same allele (cis). Both mutations were not present in the parents and appear to have occurred de novo. To our knowledge, this is the first report in the literature on an achondroplasia patient with two FGFR3 mutations on the same allele.

Congenital abnormalities of the musculoskeletal system: Perinatal evaluation and long-term outcome

Many musculoskeletal malformations can be detected by prenatal US. Whether isolated or part of a syndrome, these anomalies can have a significant impact on the entire life of the individual. Nonfatal conditions may be subtle and become more recognizable in the second and third trimester. After delivery, radiography helps confirm the diagnosis. US, CT, and MRI all have a role in imaging the primary abnormality, the follow-up effects of treatment, and in monitoring for potential complications that may develop over time. Three-dimensional imaging has an increasing role, in US, CT, and MRI, both in the prenatal and postnatal periods.

Growth and cellular differentiation: a physico-biochemical conundrum? The example of the hand

Currently, the predominant hypothesis explains cellular differentiation as an essentially genetic intracellular process. The goal of this paper is to suggest that cell growth and differentiation may be, simply, the result of physical and chemical constraints. Bone growth occurs at the level of cartilage conjunction (growth plate) in a zone of lesser constrain. It appears that this growth also induces muscle, tendon, nerve and skin elongation. This cartilage growth by itself seems to explain the elongation of the hand. Growth stops at puberty likely because of feed-back from an increasing muscle load. The ossification (that is differentiation of cartilage into bone) appears to result from the shear stress induced. The study of bone age, obtained by X-ray picture of the hand, shows that ossification of epiphyses is very precise both in time and space. Computer modelization suggests that this ossification occurs where shear stress is greatest. The cartilage which does not ossify (joint, nose, larynx, ear, bronchus, etc.) is not exposed to high shear. Shear stress induces the secretion of extracellular matrix and a change of the biochemical environment of the cell. Precipitation of calcium phosphate, as in ossification, seems related to the alkalosis induced by shear stress. To speak in more general terms, loss of cellular differentiation, as occurs with cancer, can result from a change in the physical-chemical environments.

Selections from the buffet of food signs in radiology

Certain pathologic conditions have classic radiologic manifestations that resemble various types of food. These "food signs" are highly memorable and easily recognizable and include findings that resemble various fruits and vegetables; meat, fish, and egg dishes; pasta, rice, grains, and bread (carbohydrates); desserts, cakes, and candy; and dishes, cutlery, condiments, and so on. It is important that radiologists recognize these classic signs, which will allow confident diagnosis on the basis of imaging findings alone or narrowing of the differential diagnosis.