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Collision tumor of the thyroid: follicular variant of papillary carcinoma and squamous carcinoma.

Walvekar RR, Kane SV, D'Cruz AK - World J Surg Oncol (2006)

Bottom Line: Collision tumors of the thyroid gland pose a diagnostic as well as therapeutic challenge.Treatment for collision tumors depends upon the combination of primary tumors involved and each component of the combination should be treated like an independent primary.The reporting of similar cases with longer follow-up will help define the epidemiology, biology and establish standardized protocols for treatment of these extremely rare tumors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Head and Neck Surgery, Tata Memorial Hospital, Parel, Mumbai, India. rrohanw@yahoo.com

ABSTRACT

Background: Collision tumors of the thyroid gland are a rare entity. We present a case of a follicular variant of papillary carcinoma and squamous carcinoma in the thyroid. To the best of our knowledge, this is the first documentation of a collision tumor with a papillary carcinoma and a squamous carcinoma within the thyroid gland. The clinicopathological features and immunohistochemical profile are reported. The theories of origin, epidemiology and management are discussed with a literature review.

Case presentation: A 65 year old woman presented with a large thyroid swelling of 10 years duration and with swellings on the back and scalp which were diagnosed to be a follicular variant of papillary thyroid carcinoma with metastasis. Clinical examination, radiology and endoscopy ruled out any other abnormality of the upper aerodigestive tract. The patient was treated surgically with a total thyroidectomy with central compartment clearance and bilateral selective neck dissections. The histopathology revealed a collision tumor with components of both a follicular variant of papillary carcinoma and a squamous carcinoma. Immunohistochemical analysis confirmed the independent origin of these two primary tumors. Adjuvant radio iodine therapy directed toward the follicular derived component of the thyroid tumor and external beam radiotherapy for the squamous component was planned.

Conclusion: Collision tumors of the thyroid gland pose a diagnostic as well as therapeutic challenge. Metastasis from distant organs and contiguous primary tumors should be excluded. The origins of squamous cancer in the thyroid gland must be established to support the true evolution of a collision tumor and to plan treatment. Treatment for collision tumors depends upon the combination of primary tumors involved and each component of the combination should be treated like an independent primary. The reporting of similar cases with longer follow-up will help define the epidemiology, biology and establish standardized protocols for treatment of these extremely rare tumors.

No MeSH data available.


Related in: MedlinePlus

Follicular variant of papillary carcinoma of thyroid and squamous carcinoma in close juxtaposition with each other (H&E 200×).
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Figure 1: Follicular variant of papillary carcinoma of thyroid and squamous carcinoma in close juxtaposition with each other (H&E 200×).

Mentions: Multiple sections from the thyroid mass displayed an invasive follicular variant of papillary carcinoma with foci of capsular invasion. There was an obvious extrathyroidal extension of the tumor. Juxtaposed with the papillary carcinoma in close proximity was an independent primary tumour with histology of a moderately differentiated non keratinizing squamous carcinoma. The two tumours were separated by fibrous septae over a broad area. They intermingled minimally at the interface representing a true "collision tumor" (Figure 1, 2). The follicular variant of papillary carcinoma showed a uniform follicular differentiation without papillary areas or squamous morules. Classical nuclear features of papillary carcinoma namely nuclear crowding, nuclear clearing, overlapping and grooving with irregularities of the nuclear membrane were evident (Figure 3). These two tumors were distinct morphologically and were also independent without a zone of transition from papillary to squamous carcinoma. As the squamous carcinoma was non-keratinizing in nature, keratin pearls were not seen but clusters of cohesive cells with abundant eosinophilic cytoplasm and distinct cytoplasmic borders were noted (Figure 4, 5). The squamous carcinoma revealed a large area of cystic degeneration in the center and also showed muscle infiltration at the periphery. A diligent search failed to reveal remnants of thyroglossal cyst or areas of anaplastic carcinoma. There was an absence of lymphoid tissue around the component of squamous carcinoma. The uninvolved lobe showed no evidence of Hashimoto's thyroiditis.


Collision tumor of the thyroid: follicular variant of papillary carcinoma and squamous carcinoma.

Walvekar RR, Kane SV, D'Cruz AK - World J Surg Oncol (2006)

Follicular variant of papillary carcinoma of thyroid and squamous carcinoma in close juxtaposition with each other (H&E 200×).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1622750&req=5

Figure 1: Follicular variant of papillary carcinoma of thyroid and squamous carcinoma in close juxtaposition with each other (H&E 200×).
Mentions: Multiple sections from the thyroid mass displayed an invasive follicular variant of papillary carcinoma with foci of capsular invasion. There was an obvious extrathyroidal extension of the tumor. Juxtaposed with the papillary carcinoma in close proximity was an independent primary tumour with histology of a moderately differentiated non keratinizing squamous carcinoma. The two tumours were separated by fibrous septae over a broad area. They intermingled minimally at the interface representing a true "collision tumor" (Figure 1, 2). The follicular variant of papillary carcinoma showed a uniform follicular differentiation without papillary areas or squamous morules. Classical nuclear features of papillary carcinoma namely nuclear crowding, nuclear clearing, overlapping and grooving with irregularities of the nuclear membrane were evident (Figure 3). These two tumors were distinct morphologically and were also independent without a zone of transition from papillary to squamous carcinoma. As the squamous carcinoma was non-keratinizing in nature, keratin pearls were not seen but clusters of cohesive cells with abundant eosinophilic cytoplasm and distinct cytoplasmic borders were noted (Figure 4, 5). The squamous carcinoma revealed a large area of cystic degeneration in the center and also showed muscle infiltration at the periphery. A diligent search failed to reveal remnants of thyroglossal cyst or areas of anaplastic carcinoma. There was an absence of lymphoid tissue around the component of squamous carcinoma. The uninvolved lobe showed no evidence of Hashimoto's thyroiditis.

Bottom Line: Collision tumors of the thyroid gland pose a diagnostic as well as therapeutic challenge.Treatment for collision tumors depends upon the combination of primary tumors involved and each component of the combination should be treated like an independent primary.The reporting of similar cases with longer follow-up will help define the epidemiology, biology and establish standardized protocols for treatment of these extremely rare tumors.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Head and Neck Surgery, Tata Memorial Hospital, Parel, Mumbai, India. rrohanw@yahoo.com

ABSTRACT

Background: Collision tumors of the thyroid gland are a rare entity. We present a case of a follicular variant of papillary carcinoma and squamous carcinoma in the thyroid. To the best of our knowledge, this is the first documentation of a collision tumor with a papillary carcinoma and a squamous carcinoma within the thyroid gland. The clinicopathological features and immunohistochemical profile are reported. The theories of origin, epidemiology and management are discussed with a literature review.

Case presentation: A 65 year old woman presented with a large thyroid swelling of 10 years duration and with swellings on the back and scalp which were diagnosed to be a follicular variant of papillary thyroid carcinoma with metastasis. Clinical examination, radiology and endoscopy ruled out any other abnormality of the upper aerodigestive tract. The patient was treated surgically with a total thyroidectomy with central compartment clearance and bilateral selective neck dissections. The histopathology revealed a collision tumor with components of both a follicular variant of papillary carcinoma and a squamous carcinoma. Immunohistochemical analysis confirmed the independent origin of these two primary tumors. Adjuvant radio iodine therapy directed toward the follicular derived component of the thyroid tumor and external beam radiotherapy for the squamous component was planned.

Conclusion: Collision tumors of the thyroid gland pose a diagnostic as well as therapeutic challenge. Metastasis from distant organs and contiguous primary tumors should be excluded. The origins of squamous cancer in the thyroid gland must be established to support the true evolution of a collision tumor and to plan treatment. Treatment for collision tumors depends upon the combination of primary tumors involved and each component of the combination should be treated like an independent primary. The reporting of similar cases with longer follow-up will help define the epidemiology, biology and establish standardized protocols for treatment of these extremely rare tumors.

No MeSH data available.


Related in: MedlinePlus