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Solitary reticulohistiocytoma
ABSTRACTS
38. NORMAL HISTOLOGIC VARIATIONS IN THE PITUITARY GLANDS J. H. Kim, S. H. Jung Ajou University School of Medicine, Suwon, South Korea Background: The pituitary gland has normal histologic variations, such as basophil invasion, squamous cell nests, salivary gland rests, lymphocytic foci and granular cell tumorlets. These histologic variations in pituitary gland could be of importance clinically when they mimic clinically significant other lesions. Aims: In present study, we investigated incidences and clinicopathologic characteristics of normal histologic variations in the pituitary gland. Methods: We examined 121 cases of surgically resected pituitary specimen and 104 cases of autopsy pituitary glands from autopsy and investigated the incidence, age and sex difference of the normal histologic variations in the pituitary glands and compared the characteristics between surgical resected specimens and autopsy specimens. Results and Conclusions: In autopsy pituitary glands, basophil invasion (40.3%) was most commonly observed, and squamous cell nest (28.8%), lymphocytic foci (13.5%), granular cell tumorlet (3.8%) and salivary gland rest (2.9%) followed. Squamous cell nests revealed female preponderance, whereas basophil invasion showed male preponderance. No significant age difference between histologic variations was present. In surgically resected pituitary glands, however, lymphocytic foci (7.4%) were most frequently identified, and squamous cell nest (1.7%) and salivary gland rest (1.7%) followed. Neither basophil invasion nor granular cell tumorlet were identified in surgically resected pituitary specimens. Normal histologic variations in the pituitary gland were relatively common in autopsy specimens but were rarely identified in surgically resected specimens. Although normal histologic variations in the pituitary gland are not common, they could be found in surgical specimens and make a pathologic diagnosis difficult, especially during intraoperative diagnosis. Therefore, pathologists need to pay attention to these histologic variations when making a diagnosis of pituitary lesions. 39. SOLITARY RETICULOHISTIOCYTOMA L. Mogie1, H. Kasmeridis2 1 SA Pathology, Royal Adelaide Hospital, Adelaide, and 2SA Pathology, The Queen Elizabeth Hospital, Woodville, Australia Background: A 73 year old male underwent an elliptical skin excision from the right lateral thigh, clinically thought to be a dermatofibroma. Aim: To present a case report of solitary reticulohistiocytoma, a rare dermatological lesion. Results: Histological sections revealed a well circumscribed lesion within the dermis comprised of large, histiocytic-like cells with abundant, eosinophilic, ground-glass cytoplasm and scattered background inflammatory cells. Immunohistochemistry revealed positive staining for CD68 with patchy weak staining for S100, SMA and Factor XIIIa. There was negative staining for AE1/3 and Desmin. The case was referred to an expert in soft tissue pathology where the diagnosis of a solitary reticulohistiocytoma was confirmed.
S135
Conclusions: Solitary reticulohistiocytomas typically occur in adults, most commonly on the head and neck.1 It has been postulated that reticulohistiocytomas are reactive in nature, occurring secondary to an inflammatory stimulus, although the exact aetiology is undetermined.1 Surgical excision is considered curative and recurrences are deemed rare, including in patients with incomplete surgical excision of the lesion.2,3 The number of differential diagnoses is substantial and careful histological evaluation is required. References 1. Shibuya R, Tanizaki H, Kaku Y, et al. A plaque-type solitary reticulohistiocytoma in a two-year-old boy. Case Rep Dermatol 2015; 7: 7–9. 2. Cohen PR, Lee RA. Adult-onset reticulohistiocytoma presenting as a solitary asymptomatic red knee nodule: report and review of clinical presentations and immunohistochemistry staining features of reticulohistiocytosis. Dermatol Online J 2014; Mar 17; 20(3). 3. Mannan AR, Kahvic M, Singh NG, Zahir M. Solitary epithelioid histiocytoma (reticulohistiocytoma) of the glans penis. Int Urol Nephrol 2012; 44: 1345–8.
40. CASE REPORT: TWO UNUSUAL LESIONS IN THE BREAST FROM HOOKWIRE LOCALISED EXCISION J. Chen, A. Mani Tamworth Rural Referral Hospital, Tamworth, Australia Background: Hookwire localised excisions are frequently done for local resection and histopathological evaluation of breast lumps. In addition to primary tumours of the breast, tumours arising from other organs may rarely metastasise to the breast, notably lymphoma, leukaemia and malignant melanoma. Inflammatory and infective processes may also arise in breast tissue. These entities may mimic primary breast tumours on clinical examination and imaging. Results: Case 1: A 46-year-old female underwent excision of a breast lump. Microscopy revealed a circumscribed neoplasm composed of sheets and nests of polygonal and slightly spindled cells. Immunostains were positive for melanoma markers, S-100, SOX10 and HMB-45. Staging computed tomography subsequently revealed extensive liver metastases. Past history of melanoma was denied, however the patient had previously had junctional naevi excised in 2009. Case 2: A 57-year-old female underwent excision of a breast lump. Microscopy showed lymphoid tissue with marked follicular hyperplasia and microgranulomas. Toxoplasmosis was the main differential diagnosis based on morphology. Toxoplasma serology was subsequently requested by the clinician. Conclusion: Metastatic melanoma to the breast may be the first presenting sign of disseminated metastases from previously excised melanocytic lesions. These may masquerade as poorly differentiated mammary ductal or sarcomatoid carcinoma. Prompt diagnosis is crucial to prevent delayed therapeutic opportunity given the increasing availability of molecularly targeted therapy. Infective and inflammatory conditions such as toxoplasmosis may also present as an intramammary mass, and remain important differential diagnoses when evaluating the breast lump. 41. CIC-REARRANGED SARCOMA: A CASE REPORT H. Narayanappa1, R. Boyle2, R. Karim1, W. Brown3, W. Cooper1,4, C. Selinger4, F. Bonar5, A. Mahar1 1 Department of Pathology, 2Department of Orthopaedic Surgery, 3Department of Radiology, 4Department of Molecular
38. NORMAL HISTOLOGIC VARIATIONS IN THE PITUITARY GLANDS J. H. Kim, S. H. Jung Ajou University School of Medicine, Suwon, South Korea Background: The pituitary gland has normal histologic variations, such as basophil invasion, squamous cell nests, salivary gland rests, lymphocytic foci and granular cell tumorlets. These histologic variations in pituitary gland could be of importance clinically when they mimic clinically significant other lesions. Aims: In present study, we investigated incidences and clinicopathologic characteristics of normal histologic variations in the pituitary gland. Methods: We examined 121 cases of surgically resected pituitary specimen and 104 cases of autopsy pituitary glands from autopsy and investigated the incidence, age and sex difference of the normal histologic variations in the pituitary glands and compared the characteristics between surgical resected specimens and autopsy specimens. Results and Conclusions: In autopsy pituitary glands, basophil invasion (40.3%) was most commonly observed, and squamous cell nest (28.8%), lymphocytic foci (13.5%), granular cell tumorlet (3.8%) and salivary gland rest (2.9%) followed. Squamous cell nests revealed female preponderance, whereas basophil invasion showed male preponderance. No significant age difference between histologic variations was present. In surgically resected pituitary glands, however, lymphocytic foci (7.4%) were most frequently identified, and squamous cell nest (1.7%) and salivary gland rest (1.7%) followed. Neither basophil invasion nor granular cell tumorlet were identified in surgically resected pituitary specimens. Normal histologic variations in the pituitary gland were relatively common in autopsy specimens but were rarely identified in surgically resected specimens. Although normal histologic variations in the pituitary gland are not common, they could be found in surgical specimens and make a pathologic diagnosis difficult, especially during intraoperative diagnosis. Therefore, pathologists need to pay attention to these histologic variations when making a diagnosis of pituitary lesions. 39. SOLITARY RETICULOHISTIOCYTOMA L. Mogie1, H. Kasmeridis2 1 SA Pathology, Royal Adelaide Hospital, Adelaide, and 2SA Pathology, The Queen Elizabeth Hospital, Woodville, Australia Background: A 73 year old male underwent an elliptical skin excision from the right lateral thigh, clinically thought to be a dermatofibroma. Aim: To present a case report of solitary reticulohistiocytoma, a rare dermatological lesion. Results: Histological sections revealed a well circumscribed lesion within the dermis comprised of large, histiocytic-like cells with abundant, eosinophilic, ground-glass cytoplasm and scattered background inflammatory cells. Immunohistochemistry revealed positive staining for CD68 with patchy weak staining for S100, SMA and Factor XIIIa. There was negative staining for AE1/3 and Desmin. The case was referred to an expert in soft tissue pathology where the diagnosis of a solitary reticulohistiocytoma was confirmed.
S135
Conclusions: Solitary reticulohistiocytomas typically occur in adults, most commonly on the head and neck.1 It has been postulated that reticulohistiocytomas are reactive in nature, occurring secondary to an inflammatory stimulus, although the exact aetiology is undetermined.1 Surgical excision is considered curative and recurrences are deemed rare, including in patients with incomplete surgical excision of the lesion.2,3 The number of differential diagnoses is substantial and careful histological evaluation is required. References 1. Shibuya R, Tanizaki H, Kaku Y, et al. A plaque-type solitary reticulohistiocytoma in a two-year-old boy. Case Rep Dermatol 2015; 7: 7–9. 2. Cohen PR, Lee RA. Adult-onset reticulohistiocytoma presenting as a solitary asymptomatic red knee nodule: report and review of clinical presentations and immunohistochemistry staining features of reticulohistiocytosis. Dermatol Online J 2014; Mar 17; 20(3). 3. Mannan AR, Kahvic M, Singh NG, Zahir M. Solitary epithelioid histiocytoma (reticulohistiocytoma) of the glans penis. Int Urol Nephrol 2012; 44: 1345–8.
40. CASE REPORT: TWO UNUSUAL LESIONS IN THE BREAST FROM HOOKWIRE LOCALISED EXCISION J. Chen, A. Mani Tamworth Rural Referral Hospital, Tamworth, Australia Background: Hookwire localised excisions are frequently done for local resection and histopathological evaluation of breast lumps. In addition to primary tumours of the breast, tumours arising from other organs may rarely metastasise to the breast, notably lymphoma, leukaemia and malignant melanoma. Inflammatory and infective processes may also arise in breast tissue. These entities may mimic primary breast tumours on clinical examination and imaging. Results: Case 1: A 46-year-old female underwent excision of a breast lump. Microscopy revealed a circumscribed neoplasm composed of sheets and nests of polygonal and slightly spindled cells. Immunostains were positive for melanoma markers, S-100, SOX10 and HMB-45. Staging computed tomography subsequently revealed extensive liver metastases. Past history of melanoma was denied, however the patient had previously had junctional naevi excised in 2009. Case 2: A 57-year-old female underwent excision of a breast lump. Microscopy showed lymphoid tissue with marked follicular hyperplasia and microgranulomas. Toxoplasmosis was the main differential diagnosis based on morphology. Toxoplasma serology was subsequently requested by the clinician. Conclusion: Metastatic melanoma to the breast may be the first presenting sign of disseminated metastases from previously excised melanocytic lesions. These may masquerade as poorly differentiated mammary ductal or sarcomatoid carcinoma. Prompt diagnosis is crucial to prevent delayed therapeutic opportunity given the increasing availability of molecularly targeted therapy. Infective and inflammatory conditions such as toxoplasmosis may also present as an intramammary mass, and remain important differential diagnoses when evaluating the breast lump. 41. CIC-REARRANGED SARCOMA: A CASE REPORT H. Narayanappa1, R. Boyle2, R. Karim1, W. Brown3, W. Cooper1,4, C. Selinger4, F. Bonar5, A. Mahar1 1 Department of Pathology, 2Department of Orthopaedic Surgery, 3Department of Radiology, 4Department of Molecular