Synchronous Bony and Soft Tissue Metastases from Follicular Carcinoma of the Thyroid

Abstract

INTRODUCTIONFollicular thyroid carcinoma (FTC) is a slow-growing tumor, and is the second most common cancer of the thyroid. Distant spread may occur commonly to bones, brain and lungs. Soft tissue metastasis is extremely rare and the reported incidence of distant metastasis is between 11 and 25%, while the initial presentation with distant metastasis is uncommon (1). So far to our knowledge, there is no report of a synchronous bone and soft tissue metastases in the literature. We conducted this study based on the extremely rare case of soft tissue metastasis. CASE REPORTA 42-yr-old male presented with a non-toxic solitary thyroid nodule (STN) of 5 yr of duration with swellings on the scalp and on the right forearm with the durations of 3 and 2 months respectively. There was no other significant contributory history.On examination, the general condition and vital signs were normal. A left STN measuring 5×3 cm was present, and was hard in consistency. There was no cervical lymphadenopathy. The left parietal region swelling was firm, non-tender, welldefined and measured 7×5 cm. A bony defect was palpable. The right forearm subcutaneous swelling was hard, non-tender, mobile and well-defined (Fig. 1).Investigations revealed a normal hemogram and chest radiography. Radiography of the skull revealed the erosion of the outer table of the left parietal bone (Fig. 2). Fine needle aspiration cytology (FNAC) from the thyroid nodule, swellings on the scalp and the forearm revealed atypical follicular cells, suggesting a follicular neoplasm. A complete excision with adequate free margins (2 cm) of the swelling on the forearm was carried out under local anesthesia, and the histopathology revealed fibrous septae separating colloid-filled follicles lined by cuboidal follicular cells with areas of Hurthle cell change, anisonucleosis and scalloping of colloid with pseudopapillary hyperplasia (Fig. 3). Serum thyroglobulin (TG) level was found to be 580 ng/mL (normal ≤60 ng/mL). Hence, a diagnosis of FTC with synchronous metastases to bone and soft tissue was made.The patient was operated upon in two phases. First a total thyroidectomy was executed. There were no palpable enlarged lymph nodes, intraoperatively, in the neck. A week later, the scalp swelling was excised widely with adequate margins (2 cm). Final histopathology report showed follicular carcinoma in both specimens (features as described above, with presence of both capsular and vascular invasion). Post-operative period was uneventful. At the end of the 3rd week, serum thyroglobulin levels had reverted back to normal. A 131 I whole body scan at the end of the 5th week showed no residual thyroid tissue in the thyroid bed (neck), except for a hot spot in the scalp which was ablated with 131 I (30 mCi). Patient has been put on thyroxine 0.3 mg/day for life and kept under close follow-up. The patient has been free of symptoms for the next 3 yr. DISCUSSIONFTC is the second most common differentiated thyroid ma- Follicular carcinoma of the thyroid rarely manifests itself as a...

Scalp metastases from thyroid carcinomas: review of clinical and pathological features

“…[15] Face, neck, chest, arm and pelvis are the other cutaneous sites of metastasis affected with scalp. [16][17][18][19] Eighteen cases of FTC metastasis to scalp were reported in the literature [3,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] (Table 1). Two cases reported by Lissak et al [20] were follicular microcarcinoma revealed by solitary scalp lesions.…”

Papillary thyroid carcinoma presenting as a solitary soft tissue arm metastasis in an elderly hyperthyroid patient. Case report and review of the literature

“…Other localizations of follicular carcinoma, including muscle and other soft tissues, are rare and become exceptional when this metastasis is the first and only clinical manifestation of the tumor, as reported in the pelvis, medial rectus muscle or mandible [3,10,13]. Another case was described to have soft tissue metastases of a follicular carcinoma, which were, however, synchronous with bony spread [16]. PTC is commonly associated with lymphatic spread to cervical lymph nodes [7,8].…”

Diagnostic clue of nodular fasciitis mimicking metastasis in papillary thyroid cancer, mismatching findings on 18F-FDG PET/CT and 123I whole body scan: A case report

“…This proportion is only 4-15% in the case of differentiated thyroid cancers (7,8). Common sites of metastasis include the lungs and bones (8)(9)(10)(11), while soft tissue metastasis is reportedly extremely rare (12)(13)(14). Although distant metastasis in patients with thyroid cancer is not as grave as that in other cancers, it significantly affects survival; therefore, a thorough work-up including 18 F-FDG PET/CT is required (9,15,16).…”