Answer for BIR CoW 10 Aug 2025
Fanconi’s anemia with hypoplastic right thumb( TYPE IIIB by Blauth classification)
Findings:
•Evidence of hypoplasia of proximal two thirds of the first right metacarpal bone with deficient first Carpometacarpal articulation noted. The scaphoid also appears hypoplastic.Other metacarpals, carpals and phalanges appear normal. Distal radius and ulna appear normal.
•Complete blood count revealed- WBC count 2.8x 103/microliter ,RBC count -2.03x106/microliter ,hemoglobin-6.4 g/dl ,HCT- 19.6%,platelet count -11x103/microliter.
Discussion:
General
Skeletal / Radiological Features
Genitourinary (30%)
Other Systems
Hematologic
Differential Diagnoses for Radial Ray / Thumb Abnormalities
Radiology Relevance
References:
•Obstetric imaging:Fetal diagnosis and care,Joshua A.Copel et al.
•Operative Techniques: Hand and Wrist Surger-Kevin C. Chung
•De Kerviler E, Guermazi A, Zagdanski AM, Gluckman E, Frija J. The clinical and radiological features of Fanconi's anaemia. Clin Radiol. 2000 May;55(5):340-5. doi: 10.1053/crad.2000.0445. PMID: 10816398.
•Bhandari J, Thada PK, Killeen RB, et al. Fanconi Anemia. [Updated 2024 Jun 19]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK559133/
TY - JOURAU - Basat, SalihAU - Orman, CagdasAU - Kayadibi, TurgutAU - scetin, IlkerAU - Bozkurt, MehmetPY - 2014/01/01SP - 1T1 - HYPOPLASTIC THUMB TYPE IIIB: AN ALTERNATIVE METHOD FOR SURGICAL REPAIRVL - DO - 10.5455/handmicrosurg.168124JO - Hand and MicrosurgeryER
Findings:
•Evidence of hypoplasia of proximal two thirds of the first right metacarpal bone with deficient first Carpometacarpal articulation noted. The scaphoid also appears hypoplastic.Other metacarpals, carpals and phalanges appear normal. Distal radius and ulna appear normal.
•Complete blood count revealed- WBC count 2.8x 103/microliter ,RBC count -2.03x106/microliter ,hemoglobin-6.4 g/dl ,HCT- 19.6%,platelet count -11x103/microliter.
Discussion:
General
- Rare autosomal recessive DNA repair disorder.
- Presents with pancytopenia, bone marrow failure, congenital malformations, and malignancy risk.
- ~25% may have no obvious physical anomalies.
Skeletal / Radiological Features
- Radial ray deformities (49–66%): absent/hypoplastic radius, absent/hypoplastic/thumb anomalies.
- Thumb anomalies (39–55%): hypoplastic, absent, bifid, or supernumerary.
- Hand: carpal hypoplasia, hypoplastic thenar eminence, clinodactyly (5th finger).
- Other skeletal: spina bifida, rib hypoplasia, hip dysplasia/dislocation.
- Facial: narrow face, microcephaly.
Genitourinary (30%)
- Renal anomalies: hypoplastic/aplastic kidney, ectopic/pelvic kidney, horseshoe/sigmoid kidney.
- Collecting system: duplex, VUR, hypospadias.
Other Systems
- Skin: café-au-lait spots (63–79%).
- CNS: microcephaly, microphthalmia, strabismus, ptosis, external ear anomalies → conductive hearing loss.
- CVS (28%): PDA, VSD, ASD, TOF, mitral valve prolapse, absent/displaced radial artery.
- GIT: esophageal/duodenal atresia, imperforate anus.
Hematologic
- Progressive pancytopenia, macrocytosis, ↑fetal Hb.
- 90% develop bone marrow failure by 40 years.
- High risk of AML + solid tumors (head & neck, GI, genital tract, skin).
Differential Diagnoses for Radial Ray / Thumb Abnormalities
- Holt-Oram syndrome
- Diamond-Blackfan anemia
- Nager syndrome
- Thrombocytopenia-absent radius (TAR) syndrome
- Roberts syndrome
- VACTERL association
- Townes-Brocks syndrome
Radiology Relevance
- Recognize radial ray/hand deformities → may be the first clue at birth.
- Always assess kidneys, heart, spine, hips when thumb/radius abnormalities seen.
- Suggest hematology work-up if congenital anomalies + cytopenia.
References:
•Obstetric imaging:Fetal diagnosis and care,Joshua A.Copel et al.
•Operative Techniques: Hand and Wrist Surger-Kevin C. Chung
•De Kerviler E, Guermazi A, Zagdanski AM, Gluckman E, Frija J. The clinical and radiological features of Fanconi's anaemia. Clin Radiol. 2000 May;55(5):340-5. doi: 10.1053/crad.2000.0445. PMID: 10816398.
•Bhandari J, Thada PK, Killeen RB, et al. Fanconi Anemia. [Updated 2024 Jun 19]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK559133/
TY - JOURAU - Basat, SalihAU - Orman, CagdasAU - Kayadibi, TurgutAU - scetin, IlkerAU - Bozkurt, MehmetPY - 2014/01/01SP - 1T1 - HYPOPLASTIC THUMB TYPE IIIB: AN ALTERNATIVE METHOD FOR SURGICAL REPAIRVL - DO - 10.5455/handmicrosurg.168124JO - Hand and MicrosurgeryER
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!