278 Brief reports
Histopthology 1991. 18, 278-279
BRIEF REPORT
Follicular adenoma of the thyroid gland with extensive chondroid metaplasia A.VISONA, M.PEA, L.BOZZOLA, V.STRACCA-PANSA & S.MELI Department of Morbid Anatomy and Histopathology, Ospedale Sun Bortolo, Vicenza, ltaly Date of submission 16 August 1990 Accepted for publication 2 3 October 1990
Keywords: thyroid, follicular adenoma, cartilage, metaplasia
Introduction Cartilage is an extremely rare finding within the thyroid gland. It has in fact been described in benign and malignant teratomas'*2,in the form of chondrosarcomatous foci as part of undifferentiated carcinomas3 and as
hyaline nodules in multinodular goiter4. A case is described in which a large follicular adenoma of the thyroid was predominantly composed of metaplastic mature cartilage.
Case report A 72-year-old man presented with a large mass occupy-
ing the right lobe of the thyroid: the lesion had grown
Figure 1. Cross-section of surgical specimen showing a predominantly solid lobulatcd mass with a few cystic spaces. Address for correspondence: Dr A.Visona. Anatornia e Istologia Patologica. Ospedale Civile San Boortolo, Viale Rodolfi. 37, 361 00 Vicenza. Italy.
Brief reports
2 79
capsule, grey-white in colour and predominantly solid, with a few cystic areas filled with clear fluid and lined with a rim of bluish tissue with a vaguely chondroid appearance (Figure 1). Histological examination showed that the bulk of the lump was made up of mature cartilage with small peripheral residual areas presenting the features of a microfollicular adenoma. A positive immunohistochemical reaction for thyroglobulin confirmed the follicular nature of the glandular structures compressed between the fibrous capsule and the large central cartilagineous core (Figure 2).
Discussion This case represents a very unusual variant of follicular adenoma of the thyroid gland, characterized by massive chondroid metaplasia of the stromal component. The rareness of cartilagineous tissue within benign or malignant thyroid lesions can be underlined by the few reported cases in the medical literature. Follicular adenoma with extensive chondroid metaplasia is, in our opinion, the most suitable term for this lesion. Metaplastic changes deriving from thyroidal stroma are, according to Finkle & Goldman4,the best histogenetic interpretation for these areas of heterotopic cartilage. The possibility of branchiogenic/bronchogenic origin or teratoid differentiation may alternatively be taken into account. A final possibility is that this represents a hamartomatous lesion5.
Acknowledgements
Figure 2. The cartilagineous core is surrounded by focal residual areas with a microfollicular pattern positive for thyroglobulin.ABC immunoperoxidase.
We greatly appreciate Professor J.Rosai's kind collaboration in the confirmation of the histological findings and helpful suggestions relating to this case.
References slowly over a long_ _period of time. causing-~symptoms due to tracheal compression. On scintigraphy the lump was The was resected and the patient made an uneventful recovery. He died of cardiac failure 2 years later: no autopsy was performed. PATHOLOGICAL FINDINGS
On gross examination' the resected was Oval and rubbery, measuring 10 cm in its largest diameter. On cut section it was lobulated, clearly outlined by a narrow
1. Keynes WM. Teratoma of the neck in relation to the thyroid gland.
Br. 1. Surg. 1959; 46: 466-472. 2. Meissner WA, Warren S. Tumors of the thyroid gland. In: Atlas o/ Tumor Pathology. 2nd series, fascicle 4, Washington Dc: Armed Forces Institute of Pathology. __ 1969. 3. Hedinger C. Histological typing of thyroid tumours. In: WHO International Histological Classification of Tumours. 2nd Ed. Berlin: Springer-Verlag. 1988. 4. Finkle, HI, Goldman RL. Heterotopic cartilage in the thyroid. Arch. Pathol. 1973: 95; 48-49. 5. Chahal AS, Subramanyam CSV. Bhattacharjea AK. Chondromatous hamartoma of the thvroid gland. Aust. NZ ~7. Sura 1975; 45; 30-31.
-
-
Histopthology 1991. 18, 278-279
BRIEF REPORT
Follicular adenoma of the thyroid gland with extensive chondroid metaplasia A.VISONA, M.PEA, L.BOZZOLA, V.STRACCA-PANSA & S.MELI Department of Morbid Anatomy and Histopathology, Ospedale Sun Bortolo, Vicenza, ltaly Date of submission 16 August 1990 Accepted for publication 2 3 October 1990
Keywords: thyroid, follicular adenoma, cartilage, metaplasia
Introduction Cartilage is an extremely rare finding within the thyroid gland. It has in fact been described in benign and malignant teratomas'*2,in the form of chondrosarcomatous foci as part of undifferentiated carcinomas3 and as
hyaline nodules in multinodular goiter4. A case is described in which a large follicular adenoma of the thyroid was predominantly composed of metaplastic mature cartilage.
Case report A 72-year-old man presented with a large mass occupy-
ing the right lobe of the thyroid: the lesion had grown
Figure 1. Cross-section of surgical specimen showing a predominantly solid lobulatcd mass with a few cystic spaces. Address for correspondence: Dr A.Visona. Anatornia e Istologia Patologica. Ospedale Civile San Boortolo, Viale Rodolfi. 37, 361 00 Vicenza. Italy.
Brief reports
2 79
capsule, grey-white in colour and predominantly solid, with a few cystic areas filled with clear fluid and lined with a rim of bluish tissue with a vaguely chondroid appearance (Figure 1). Histological examination showed that the bulk of the lump was made up of mature cartilage with small peripheral residual areas presenting the features of a microfollicular adenoma. A positive immunohistochemical reaction for thyroglobulin confirmed the follicular nature of the glandular structures compressed between the fibrous capsule and the large central cartilagineous core (Figure 2).
Discussion This case represents a very unusual variant of follicular adenoma of the thyroid gland, characterized by massive chondroid metaplasia of the stromal component. The rareness of cartilagineous tissue within benign or malignant thyroid lesions can be underlined by the few reported cases in the medical literature. Follicular adenoma with extensive chondroid metaplasia is, in our opinion, the most suitable term for this lesion. Metaplastic changes deriving from thyroidal stroma are, according to Finkle & Goldman4,the best histogenetic interpretation for these areas of heterotopic cartilage. The possibility of branchiogenic/bronchogenic origin or teratoid differentiation may alternatively be taken into account. A final possibility is that this represents a hamartomatous lesion5.
Acknowledgements
Figure 2. The cartilagineous core is surrounded by focal residual areas with a microfollicular pattern positive for thyroglobulin.ABC immunoperoxidase.
We greatly appreciate Professor J.Rosai's kind collaboration in the confirmation of the histological findings and helpful suggestions relating to this case.
References slowly over a long_ _period of time. causing-~symptoms due to tracheal compression. On scintigraphy the lump was The was resected and the patient made an uneventful recovery. He died of cardiac failure 2 years later: no autopsy was performed. PATHOLOGICAL FINDINGS
On gross examination' the resected was Oval and rubbery, measuring 10 cm in its largest diameter. On cut section it was lobulated, clearly outlined by a narrow
1. Keynes WM. Teratoma of the neck in relation to the thyroid gland.
Br. 1. Surg. 1959; 46: 466-472. 2. Meissner WA, Warren S. Tumors of the thyroid gland. In: Atlas o/ Tumor Pathology. 2nd series, fascicle 4, Washington Dc: Armed Forces Institute of Pathology. __ 1969. 3. Hedinger C. Histological typing of thyroid tumours. In: WHO International Histological Classification of Tumours. 2nd Ed. Berlin: Springer-Verlag. 1988. 4. Finkle, HI, Goldman RL. Heterotopic cartilage in the thyroid. Arch. Pathol. 1973: 95; 48-49. 5. Chahal AS, Subramanyam CSV. Bhattacharjea AK. Chondromatous hamartoma of the thvroid gland. Aust. NZ ~7. Sura 1975; 45; 30-31.
-
-
