Skeletal Radiol (1991) 20:534-538
Case report 693 A. Giedion, M.D. 1, K. Biedermann, M.D. 2, 3. Briner, M.D. 3, R. Soler, M.D. 3, and M. Spycher, Ph.D. 3
1 Department of Radiology, University Children's Hospital Departments of 2 Gynecology and 3 Pathology, University of Zfirich, Ziirich, Switzerland
Figs. 1-3. See next page for corresponding captions
9 1991 International Skeletal Society
A. Giedion et al. : Case report 693 535
Fig. 1. Aborted fetus at 23 weeks gestation Fig. 2A, B. Babygram. The numbers corre- spond to those in Table 2. Besides the snail- like configuration of the iliac wings (large arrow) note also the generalized edema, the prominent mandible with obtuse angle, the lumbosacral lordosis (thin arrow) and the spoon- or fork-like anterior ends of the ribs
Fig. 3A, B. Magnified view of right ilium shows some resemblance to the silhouette of a snail, but perhaps more to that of a turtle
Fig. 4. A Upper and B lower extremity and C macroscopic view of femur. Besides severe brachymelia, dumbbell-shaped femur and brachymesophalangy, metaphyseal spur for- mation is observed (arrow), corresponding to the increased periosteal ossification visi- ble (arrow) on the macroscopic cut Fig. 5. Ultrasonogram of fetus at 13 2/7 weeks, third pregnancy. Trunk and head are of normal size, the extremities only frag- mentarily visible due to extreme micromelia. Arrow, lower extremities
Address reprint requests to: Prof. A. Gie- dion, Department of Radiology, University Children's Hospital, Steinwiesstrasse 75, CH-8032 Ziirich, Switzerland
The parents are first-degree cousins of Italian extraction. The first fetus was aborted at 23 weeks of gestation (mother aged 23 years) as the ultra- sonographic findings were consid- ered incompatible with life. The fol- lowing two pregnancies were each in- terrupted at 14 weeks (mother aged 24 and 26 years) after recognition of the same type of short-limbed skele- tal dysplasia.
Index case-physical examination
Figure 1 shows the aborted fetus at 23 weeks of gestation, mother 23 years old. Weight 430 g, crown-heel length 17.5 cm. Female with large head, "sunken- in" fiat nose, hardly visible neck, short rump, extreme mi- cromelia and large hands and feet. Severe edema of scalp, face, neck, and back was also present
Radiographic findings' (further de- scriptions)
Skull: Well ossified, steep base, later- ally raised orbits ("Mephistophelian look"), flat face, prominent mandible with obtuse angle are characteristic.
Spine." Narrow interpediculate dis- tances and generalized platyspondyly are present in the anteroposterior view. In the lateral view the vertebral bodies are round, connected by a thread-like bony bridge with the re- mainder of the spine. Lumbosacral lordosis of almost 90 is seen with nar- row sacral centers. The short ribs end in a spoon- or fork-like pattern. Cla- vicular hooks, in oblique view "han- dlebar-like," are noted. The short scapulae are framed by a dense border. Small ilia with "snail-like configuration" are typical with the head of the snail protruding from the shell (the sorthened iliac wings) look- ing towards the upper sacral region. A horizontal acetabular roof and a well-ossified pubis and ischium are present. The long bones are very short, the femur and humerus dumb- bell-shaped. Some metaphyseal spur formation of humerus, ulna, and fe- mur is usually found.
Hands and feet: These are relatively large. Brachymetacarpism and bra- chymesophalangism are noted. Ossi- fication centers of the talus, calcan- eus, and (?) cuboid are visible.
536 A. Giedion et al. : Case report 693
Diagnosis: Schneckenbecken dysplasia
Gross findings: In addition to the al- ready described deformities of skull, rump, and extremities, hypoplastic lungs were noted. No abnormal find- ings of other organs were present.
Microscopic findings (see Fig.6): Generalized disturbance of cartilage formation (also noted in laryngeal, tracheal, and bronchial cartilage) re- sulted in severe reduction of intercel- lular matrix in the markedly hyper- cellular resting and proliferating zones. Vascular penetration was in- creased, and the columns of prolifer- ating cartilage were massively short- ened and irregular. Increased perios- teal ossification led to bony spurs, extending membranous ossification to the lateral aspects of the epiphy- seal line.
Electronmicroseopie findings (consid- ered nonspec~'c) : The ultrastructure of the resting cartilage of the femoral head was inconspicuous in the epi- physeal plate; however, a severe dis-
turbance of the arrangement of the columnar cells was observed. The cell columns were short, and an increased number of degenerating and necrotic cells was seen in the proliferating and hypertrophic zones. The cytoplasm of chondrocytes contained flattened cisternae of rough endoplasmic retic- ulum, occasionally distended by a granular material of moderate elec- tron density, scanty Golgi areas, some small dense lysosomal inclu- sions, and scattered, small lipid drop- lets. No pathological inclusions could be detected. The extracellular matrix consisted of fine collagen fi- brils up to 30 nm in diameter and numerous proteoglycan particles. Matrix vesicles were seen mainly in the pericellular matrix of the epiphy- seal chondrocytes.
Case 2 and 3: The extremely short extremities were recognized by ultra- sonography at as early as 13 weeks; and the pregnancies "at risk" ter- minated at 14 weeks by suction curet- tage. The fetuses were received in fragments, but the histological find- ings of numerous long bones were identical to those of case 1.
Fig. 6. Histological section of femoral epiphyseal plate (H & E, x 80). The severe reduction of the intercellular matrix leads to a hypercellular appearance of the resting and proliferating zones with short and disori- ented columns
The Schneckenbecken dysplasia (SBD) is the best characterized newer addition to the ever-growing list of "bone dysplasia lethal before or shortly after birth" . The diag- nostic key for this autosomal-reces- sive, neonatally lethal, short-limbed, platyspondylic dwarfism (NLSLPD) is offered by radiology, in particular by the "snail-like configuration of the hypoplastic iliac bones" . Our report, the first one after the original paper, of a family with three affected siblings brings the total of observa- tions to 14 cases seen in 5 different families.
Our observation corresponds in all details to the entity of SBD described in 1986 by Borochowitz et al. . These authors added to their own personal experiences (4 cases) pre- viously published reports of "fami- lial recurring thanatophoric dwarf- ism" , "probable achondrogene- sis" , and "a new category of short-limbed dwarfism" , bringing the total to 6 males and 5 females. In 3 of the 4 families observed, the parents were first-degree cousins and 1-4 additional siblings were affected, so that an autosomal recessive trans- mission (also confirmed by our ob- servation) is likely. In 9 of 14 cases, including ours, the pregnancy was complicated by polyhydramnios; 6 were stillbirths, and in 5 cases a ther- apeutic abortion was induced. Only 3 of 14 babies lived up to 30 min.
The clinical and radiological find- ings, the latter documented in 5 cases, place SBD in the group of per- inatally lethal, short-limbed, platysp- ondylic dwarfism (PLSLPSD)  (Table 1).
Among various typical radiologic features (Table 2) it is the snail-like ilium, together with the vertebral bodies, flat in the AP, yet round in the lateral view, that permits a specif- ic diagnosis within the PLSLPSD group. The most common of all, thanatophoric dysplasia (TD) shares the inverted U-shaped vertebrae, but on the lateral view the vertebral body is not round and bullet-shaped. The typical trident ilium of TD is entirely different from the snail-like finding in SBD; the long bones are some-
A. Giedion et al. : Case report 693 537
Table 1. Perinatally lethal, short-limbed, platyspondylic dwarfism
Relatively rare :
Recently reported isolated cases or families :
Short rib-polydactyly syndromes :
Thanatophoric dysplasia Osteogenesis imperfecta II
Thanatophoric dysplasia and cloverleaf skull Achondrogenesis, Hypochondrogenesis Lethal spondyloepiphyseal dysplasia Schneckenbecken dysplasia
De la Chapelle dysplasia  Fibrochondrogenesis Neonatally lethal, short-limbed, platyspondylic dwarfism, types Torrance, San Diego , Luston 
With irregular, patchy, moth-eaten, extraneous pattern of ossification: [2, 6, 13]; metatropic-like:  A new type of achondrogenesis , Sedaghatian congenital lethal metaphyseal chondrodys- plasia [14, 15] (Platyspondyly not marked or missing)
Table 2. Radiological findings in Schneckenbecken dysplasia
Short-limbed dwarfism with short ribs and platyspondyly Normal mineralization
Skull with laterally raised orbits (" Mephistophelian look") @ Snail-like ilium (distinctive) Narrow vertebral canal, platyspondyl on AP view @ Roundish very small vertebral bodies on lateral view @ Claviculae handlebar-shaped and/or lateral clavicular hooks @ Short scapulae @ Dumbbell-shaped humerus and femur @ Relatively large hands and feet @
The numbers correspond to those of Fig. 2
what less shortened, not dumbbell- shaped, with the characteristic "tele- phone receiver-shaped femora." Two cases of SBD included in Borochow- itz's series were originally published as "famil ial thanatophor ic dwarf- ism" , thus causing much confu- sio